Asian Pacific FRIEND Report for Phase 1 (1997-2001)INTERNATIONAL HYDROLOGICAL PROGRAM Asian Pacific...

INTERNATIONAL HYDROLOGICAL PROGRAM

Asian Pacific FRIEND Report for Phase 1 (1997-2001) Flow Regimes from International Experimental and Network Data

IHP-V Project 1.1 IHP-V | Technical Documents in Hydrology | No. 9 Regional Steering Committee for Southeast Asia and the Pacific UNESCO Jakarta Office 2002

Edited by K. Takeuchi and Z. X. Xu

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PREFACE It is my great pleasure to summarize the first phase of research activities for the Asian

Pacific FRIEND (Flow Regimes from International Experiment and Network Data) (APF) conducted between 1997 and 2001 under the framework of IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific. The first phase has focused on the establishment of the objectives, work plans, research networks and the databases. Most of the scientific achievements are still in a preliminary stage. Nevertheless we are proud of the achievements as they form the basis for the development of the second phase of the Asian Pacific FRIEND.

The number of researchers involved in the APF is nearly 200 from 13 countries in the

region. They are hydrologists from governmental offices, universities and various research institutes and communicate each other mainly via the e-mail Mailing List [email protected]. Such a collaborative network has never been realized in the region before.

IHP FRIEND started in the early 1980s, firstly by Northern European countries, and

propagated around the world, so that there are now 8 regional FRIENDs. The APF was officially established in 1997 at the 5th RSC held at Nong Khai, Thailand. Although its history is relatively young compared with some other regional FRIENDs, the research network is firm and the basic activities are strong. Much of this strength comes from the APF being under the auspices of the RSC framework, which was established in 1993. The 10th RSC was held in Port Dickson, Malaysia on 18th October 2002. We celebrated the tenth anniversary with:

• Completion of four volumes of Catalogue of Rivers for Southeast Asia and the

Pacific which together include information on 94 rivers from 13 countries in the region; and, nearly

• More than 10 proceedings of symposia held in conjunction with RSC and various APF workshops.

Great achievements! At the 10th RSC, we also elected Mr. Trevor Daniell as the new

coordinator for the APF. Our region is now the hot spot of water in the world because of rapidly increasing

population, urban growth and economic development under intensifying climate variation. These factors are reflected in the growing water management issues associated with floods, water shortage and environmental pollution of water bodies. The problems of Southeast Asia and the Pacific are symbolic of the whole world. The collaborative wisdom in the region will not only benefit the region but also other regions.

I look forward to APF activities developing further in the next phase, with revised

objectives and programs under the new leadership based on the experiences and achievements of the first phase summarized here.

December 16, 2002 Kuniyoshi Takeuchi

APF Coordinator (1997-2002)

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EXECUTIVE SUMMARY The Asian Pacific FRIEND (Flow Regimes from International Experimental and

Network Data) is an IHP project organized by the IHP Regional Steering Committee for Southeast Asia and the Pacific that officially started in 1997. The project, under the umbrella title: Comparative Hydrology and Water Resources, provides a framework within which research is carried out to improve the understanding of hydrological science and water resources management in the region through comparative studies of the similarity and variability of the regional hydrological phenomena and water resource systems. The research can take advantage of the multi-continental scale coverage of the member countries and their diverse water resources management experiences. The project will progress in phases over a number of years with the first phase focusing on two major projects: establishment of the Asian Pacific Water Archive, and flood and low flow research. With the great efforts from nearly 200 members in 5 working groups, significant achievements have been obtained for the first phase of the Asian Pacific FRIEND project during the past several years.

Working Group 1 has made great efforts to collect and process hydrological data and

to establish an Asian Pacific Water Archive. The archive is Internet-based and consists of three nodes linked to each other. The central node is at the Regional Humid Tropics Hydrology and Water Resources Centre in Kuala Lumpur, Malaysia (http://htc.moa.my/apfriend/wa/). The central node acts as a gateway or portal for the two national nodes at Yamanashi University in Kofu, Japan and the Bureau of Meteorology in Melbourne, Australia. Some of the data held by the archive are available for immediate download while other data must be requested using an online request form. Individual countries may establish a node or data for the country may be made available from the central node. Presently the Water Archive holds a range of hydrological, hydrometeorological, geophysical and socio-economic information such as flood event data, annual and flood peak series and groundwater data. Initial data collection activity has concentrated on the primary data types of precipitation, streamflow and, where possible, temperature and evaporation. Currently, data for 94 rivers from 13 member countries is held on the Water Archive. Daily time series are included where possible (such as New Zealand and Australia), with data for other countries predominantly monthly time series.

Working Group 2 in AP FRIEND aimed to reduce the uncertainty in flow prediction and to assess the impact of land use changes and climate variation on floods and low flows. For this purpose the members in this group have progressed the development of rainfall-runoff models that can be used in data scarce basins to improve the predictability of floods and low flows. Different kinds of rainfall-runoff models used in the Asia and Pacific region were calibrated and validated. Several new models were developed and tested. As examples of these efforts, the 4-layer tank model was applied to five different catchments in Southeast Asia. Results obtained in some basins show that rainfall intensity strongly depends on elevation and basin aspect in relation to the direction of monsoon winds. Two distributed hydrological models, a grid-based distributed model and a hill-slope network model, have been used to simulate evapotranspiration, infiltration, groundwater flow and river flow as continuous daily simulations. A physically based rainfall-runoff model BTOPMC (Block-wise use of TOPMODEL coupled with Muskingum-Cunge method) has been developed and tested at Yamanashi University. This model is especially applicable to large, data-sparse basins. The successful

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applications of BTOPMC model in Japan, China, Indonesia, and Thailand have provided enough evidence to confirm the usefulness of the model for comparative hydrology and water resources assessment. Other examples also include TOPNET model developed in New Zealand and DTVGM model developed in China.

A number of different research approaches were adopted to investigate what methods were suitable for development of regional procedures in Working Group 3. Data sets were subdivided into regions, because an adequate streamflow prediction could not be achieved when the entire data set was treated as one region. The results suggest that catchments may be grouped using the Region of Influence approach followed by a streamflow clustering process based on Hosking’s H-statistic. The Artificial Neural Networks (ANNs) may also provide a method of grouping catchments in some cases. It demonstrated that the use of specific approaches for both low and high flows was required. Statistical frequency distributions were examined for the data sets to discover whether there was a flow-based relationship between the various data sets. Monte Carlo techniques in the process of probability weighted moment analysis and the measurement of similarity of homogeneous regions were also used. Decisions will be made in the future for the sustainable management and development of water resources. Long data sets of climate variables and streamflow need to be established to predict the consequences of humankind’s activities on streamflow and to manage risk. It became apparent through the research work carried by this working group that there are indeed large areas of the region without long periods of data records. Therefore, it is recommended that a concentrated effort be made to further review the availability of data to enable a more thorough examination of the data with the regionalization procedures that have been developed in Phase 1.

The aim of the Working Group 4 was to conduct comparative research and to establish a standard method of frequency analysis for the Southeast Asia and Pacific region. Activities include model selection and parameter estimation for small samples, methods for robust estimation of parameters, selection of proper extreme value frequency models and techniques for handling outliers. The working group has collected information about frequency analysis models and methods in several countries that proposed projects, and exchanged their experiences in the region through papers and presentations in the symposia and workshops during IHP-V (1997-2001). An extreme-value database HEAP (Hydrological Extremes in Asian Pacific region) has been established at Kyoto University in Japan. The HEAP database includes extreme discharge and rainfall in the Catalogue of Rivers for Southeast Asia and the Pacific and some additional extreme-value data from some countries. The HEAP is anticipated to be a part of the Asian Pacific Water Archive and to form the basis for frequency analysis studies throughout the region.

The main objective of Working Group 5 was to analyze and compare human adjustment processes used in different countries and regions for improved flood and low flow management. Possible outcomes from this group were expected to include damage estimates of floods and droughts, identification of the natural and social background to recent increases in flood and drought damage, potential damage increases from floods and droughts under increasing climatic variability, and non-structural measures to mitigate flood and drought damage. This group did not progress sufficiently to prepare a report due to the resignation of the coordinator.

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Since the Asian Pacific Science Plan has been published, nearly 200 researchers and practitioners in the region have been organized and their activities coordinated. Although programme implementation is still at an early stage, there have been notable achievements. These have included the publication of four volumes of the Catalogue of Rivers for Southeast Asia and the Pacific, covering 94 rivers from 13 member countries in the region, the establishment of the Asian Pacific Water Archive, the organization of annual Asian Pacific FRIEND symposium and the publication of a series of symposium and workshop proceedings. Collaboration with other related organizations and programmes such as GEWEX/GAME is also being established.

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ACKNOWLEDGEMENTS The main contributors for each chapter are listed below. The editors would also like

to thank many FRIEND colleagues who have contributed to this report through their research, by providing data and information to authors, and preparing text or illustrations. The editorial advice/comment on the draft of the report from Dr. Richard Ibbitt at the National Institute of Water and Atmospheric Research, New Zealand, and Mr. Ross James at the Bureau of Meteorology, Australia are gratefully appreciated. The assistance from Mr. Giuseppe Arduino at UNESCO Jakarta Office is also gratefully acknowledged. Executive summary Contributors: Kuniyoshi Takeuchi and Zongxue Xu Chapter 1 Introduction Contributors: Kuniyoshi Takeuchi and Zongxue Xu Chapter 2 Working Group 1: Asian Pacific FRIEND Water Archive Contributors: Ross James and Mohamed Nor bin Mohamed Desa Chapter 3 Working Group 2: Rainfall-Runoff Models Contributors: Kuniyoshi Takeuchi, Richard Ibbitt, Srikantha Herath, So Kazama, Kuraji Koichiro, Hiroshi Ishidaira, Akihiko Kondoh, Jun Xia, and Zongxue XU Chapter 4 Working Group 3: Statistical and Stochastic Models Contributors: Soontak Lee, Zhongmin Liang, Yasuyuki Ujihashi, and Trevor Daniell Chapter 5 Working Group 4: Frequency Analysis Models Contributor: Kaoru Takara Chapter 6 Working Group 5: Human Adjustment Models Contributor: Kasem Chunkao (resigned) Chapter 7 Summary and Recommendations Contributors: Kuniyoshi Takeuchi and Zongxue Xu Chapter 8 Conclusions Contributors: Kuniyoshi Takeuchi and Zongxue Xu References and Annexes Collated by Zongxue Xu, on the basis of the information provided by 5 working groups.

The AP FRIEND programme relies on the support of large number of universities, water authorities, and research organizations, who have contributed data, staff or financial resources to the project. Support has also been provided by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) and the Infrastructure

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Development Institute, Japan (IDI). During IHP-V (1996-2001), financial support was provided by the Ministry of

Education, Culture, Sports, Science and Technology (MEXT) of Japan (formerly Ministry of Education, Science, Sports and Culture (Monbusho)). Main financial sources are Japanese Fund-in-Trust for the International Hydrological Programme (IHP) and the Grants-in-Aid for Scientific Research as shown below. The members of Technical Sub-Committee for Asian Pacific FRIEND (APF-TSC) are grateful for this financial support from the Japanese government. • Grant-in-Aid for International Scientific Research: 08044170 (1996-1998),

Comparative Study on Rivers and Water Resources and Foundation of Hydrological Database Management Systems in Southeast Asia and the Pacific Region, PI: Prof. Kazutoshi Kan (Shibaura Institute of Technology).

• Grant-in-Aid for International Scientific Research: 09041199 (1997), Water Use and Data Environment in Southeast Asia and the Pacific--For Sustainable Development, PI: Prof. Shuichi Ikebuchi (Kyoto University).

• Grant-in-Aid for International Scientific Research: 10044342 (1998), Investigation on Recent Abnormal Hydrological Phenomena in Southeast Asia and the Pacific and Effective Countermeasures, PI: Prof. Kuniyoshi Takeuchi (Yamanashi University).

• Grant-in-Aid for Scientific Research (A): 10044156 (1998-2000), Water-Man-Earth Interaction and Sustainable Water Resources--Cooperation in East Asia and Oceania, PI: Prof. Shuichi Ikebuchi (Kyoto University).

• Grant-in-Aid for Scientific Research (A): 11694141 (1999-2000), Joint Research on Water Crisis and Solution Strategies, PI: Prof. Kuniyoshi Takeuchi (Yamanashi University).

• Grant-in-Aid for Scientific Research (B): 12574018 (2000-2002), Joint Research on Integrated Water and Sediment Management in Java and Sumatra, Indonesia, PI: Prof. Kaoru Takara (Kyoto University).

• Grant-in-Aid for Scientific Research (A): 13374001 (2001-2003), Evaluation, Management and Counter Measures for Water Resources Environment in Asia Pacific Region, PI: Prof. Shuichi Ikebuchi (Kyoto University).

• Grant-in-Aid for Special Purpose (1): 13800011 (2001-2003), Hydrologic Prediction in Ungaged/Information Poor Basins, PI: Kuniyoshi Takeuchi (Yamanashi University).

The authors and researchers wish to thank their respective organizations for allowing

them to participate in the Asian Pacific FRIEND Project. Their appreciation goes to the funding agencies that have supported them in performing research and participating in meetings across the region. The researchers also thank all the organizations for the supply of hydrological, topographical, and other data. The editors particularly would like to acknowledge the UNESCO Jakarta Office and MEXT for their valuable scientific and financial support to Asia Pacific FRIEND, including the preparation and publication of this report.

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CONTENTS PREFACE ............................................................................................................................ i EXECUTIVE SUMMARY................................................................................................. ii ACKNOWLEDGEMENTS ................................................................................................ v CONTENTS...................................................................................................................... vii 1. INTRODUCTION..................................................................................................... 1 1.1 General ...................................................................................................................... 1 1.2 Asian Pacific FRIEND: Comparative Hydrology and Water Resources .................. 1 1.3 Structure of the report ............................................................................................... 3 2. WORKING GROUP 1: ASIAN PACIFIC FRIEND WATER ARCHIVE.............. 4 2.1 Introduction ............................................................................................................... 4 2.2 Achievements ............................................................................................................ 5 2.3 Assessment ................................................................................................................ 8 2.4 Training ..................................................................................................................... 8 2.5 Further Development................................................................................................. 9 2.6 References ................................................................................................................. 9 3. WORKING GROUP 2: RAINFALL-RUNOFF MODELS.................................... 10 3.1 Introduction ............................................................................................................. 10 3.2 Main hydrological issues and the research projects proposed ................................ 11 3.3 Scientific Achievements and Assessment ............................................................... 12 3.3.1 Main achievements and practical applications .................................................... 12 3.3.2 Training and capacity building ............................................................................ 20 3.3.3 Contribution to the scientific community ............................................................ 21 3.4 Summaries and Recommendations ......................................................................... 21 3.5 References ............................................................................................................... 22 4. WORKING GROUP 3: STATISTICAL AND STOCHASTIC MODELS............ 24 4.1 Introduction ............................................................................................................. 24 4.2 Summary of Achievements ..................................................................................... 25 4.2.1 Data collection and Verification .......................................................................... 25 4.2.2 Principle Characteristics for Asian Pacific Region.............................................. 26 4.2.3 Modelling techniques used .................................................................................. 26 4.3 Scientific Assessment.............................................................................................. 35 4.3.1 Practical applications ........................................................................................... 35 4.3.2 Training and capacity building ............................................................................ 35 4.3.3 Contribution to scientific community .................................................................. 35 4.4 Summaries and recommendations........................................................................... 35 4.5 References ............................................................................................................... 36 5. WORKING GROUP 4: FREQUENCY ANALYSIS MODELS............................ 38 5.1 Introduction ............................................................................................................. 38 5.2 Research projects proposed..................................................................................... 38 5.3 Achievements and Assessment ............................................................................... 39 5.3.1 Main achievements and practical application ...................................................... 39 5.3.2 Training and capacity building ............................................................................ 42 5.3.3 Contribution to scientific community .................................................................. 43 5.4 Summary and recommendations ............................................................................. 43 5.5 References ............................................................................................................... 49 6. WORKING GROUP 5: HUMAN ADJUSTMENT MODELS .............................. 52 7. SUMMARY AND RECOMMENDATIONS......................................................... 54 7.1 Key achievements of Asia Pacific FRIEND ........................................................... 54

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7.2 Applications and future initiatives in IHP VI...........................................................54 7.3 Other issues ..............................................................................................................55 8. CONCLUSIONS......................................................................................................56 REFERENCES...................................................................................................................57 ANNEX 1. ABBREVIATIONS ....................................................................................58 ANNEX 2. COUNTRIES PARTICIPATING AND COORDINATORS.....................58 ANNEX 3. CATALOGUE OF RIVERS: RIVER BASINS INCLUDED....................60 ANNEX 4. EXAMPLES OF WORKING GROUP PUBLICATIONS.........................62

Chapter 1: Introduction

Asian Pacific FRIEND: IHP V Technical Documents in Hydrology No. 9 1

1. INTRODUCTION

1.1 General The Flow Regimes from International Experimental and Network Data (FRIEND)

grew out of the International Hydrological Decade (IHD), an international programme underpinned mostly by national financial support. Its objective was and still is to improve the understanding of hydrological variability and similarity across time and space, through mutual exchange of data, knowledge, and techniques at a regional level. The research projects in FRIEND cover a diverse range of topics from low flows, floods, rainfall-runoff modelling and streamflow generation to climate change, land use impact on hydrological processes and sediment transport. Training and capacity building is an important component of FRIEND and is carried out through training courses, workshops, conferences, symposia, distribution of technical literature, and financial support to postgraduate students (Gustard and Cole, 2002). The transfer of skills, knowledge and experience between regional projects is an important achievement of FRIEND.

FRIEND is one of the studies being undertaken by the nations of the developed world

in partnership with the nations of the developing world. It started from the idea that the potential in the results from the large number of experimental and representative basins, which had been established globally in the 1960s and 1970s, had not been fully realised. Practical applications were lacking particularly at the regional scale, the scale where these results could be most valuable for assessing water resources, predicting floods and for tackling many other water problems. The Intergovernmental Council of UNESCO’s International Hydrological Programme (IHP) in 1984 agreed to the UK’s proposal for a collaborative and ongoing project in IHP III named FRIEND.

FRIEND represents a concept of hydrological research and has grown greatly during

the past decade. Presently more than 100 countries participate in FRIEND and eight regional FRIEND projects have been successfully established: the Northern Europe (NE), the Alpine and Mediterranean (AMHY), the Southern Africa, the Nile Basin, the West and Central Africa (AOC), the Hindu-Kush Himalayan (HKH), the Asian Pacific, and the Mesoamerican and Caribbean (AMIGO). The following regional FRIEND projects are in the process of being established or will be established in the near future: Central Asia, South America, and the Persian Gulf and Caspian Sea. 1.2 Asian Pacific FRIEND: Comparative Hydrology and Water Resources

The Asian Pacific FRIEND, launched officially in 1997, is an IHP regional project organized by the IHP Regional Steering Committee for Southeast Asia and the Pacific. The science plan, prepared for Asian Pacific FRIEND under the umbrella title of Comparative Hydrology and Water Resources, identified two major areas of activity: establishment of Asian Pacific Water Archive, and Flood and Low Flow Research as the major focus of the first phase (UNESCO, 1999). As of May 2001 the following thirteen countries are participating: Australia, Cambodia, China, Indonesia, Japan, R Korea, Lao, Malaysia, New Zealand, Papua New Guinea, the Philippines, Thailand and Vietnam.

Asian Pacific FRIEND provides a framework within which research is carried out to

improve the understanding of hydrological sciences and water resources management in the region through comparative studies of the similarity and variability of the regional hydrological phenomena and water resource systems. The research can take advantage of the multi-continental scale coverage of the member countries and their diverse water


2 Asian Pacific FRIEND: IHP V Technical Documents in Hydrology No. 9

resources management experiences. The focus of research is on providing solutions to individual as well as common issues relevant to countries in the region and covers areas such as the following: 1. Better modelling of hydrological processes and application of a systems approach to

provide improved regional hydrological design and water resources management to meet the urgent needs for water and its control.

2. The impact on catchment hydrology and water resources of natural and human induced changes in land use and management practices.

3. The impact of climate variability on water resource availability and management. 4. The importance and effects of different spatial and temporal scales on hydrological

analyses to address regional issues. 5. The basic conditions needed to make water related technology transfer and exchange

possible.

A wide range of research projects are carried out by researchers throughout the region under the broad project headings defined by the Asian Pacific FRIEND project. While these individual projects have specific outcomes, the success of Asian Pacific FRIEND will be measured by the extent to which the results of research are: 1. used within the region to provide improved and up to date training of hydrology and

water resource practitioners, 2. transferred to and used by hydrology and water resource practitioners to solve

regional issues, and 3. appreciated by the global hydrological and water resources community as scientific

inputs from the regional findings and experiences.

These projects progress in phases over a number of years. The first phase focuses on the following two major projects: 1. Project 1 - Asian Pacific Water Archive: The purpose of this project is to establish

and maintain a data archive, which contains hydrometeorological data and other water resources related information for river basins in the region. The data are available for both current and future Asian Pacific FRIEND projects.

2. Project 2 - Flood and Low Flow Research: This project progresses through many smaller research projects focusing on particular aspects of flood and low flow hydrology. These individual projects are carried out by researchers throughout the region. Collaboration between projects to advance broader regional objectives is encouraged as much as possible. Working groups are formed with the responsibility of fostering this collaboration and of drawing together the results of similar research to achieve outcomes and recommendations for action that are of relevance to the wider region (UNESCO, 1999).

The establishment of Asian Pacific FRIEND involved the identification of existing

and proposed research projects in the region that were consistent with the FRIEND objectives. The research on floods and low flows involved the calibration and validation of the hydrological models currently used in the Asia and Pacific region, as well as the development and testing of new models. This process resulted in the identification of over 50 projects and proposals that were grouped into five broad areas, each to be coordinated by a working group. The research projects and proposals are described in more detail in UNESCO (1999).



1.3 Structure of the report This report is produced to mark the successful ending of phase one for the Asian

Pacific FRIEND (1997-2001). It summarises and, while not including all activities carried out, presents the major research output achieved during the first phase of Asian Pacific FRIEND. It gives the reader an overview of the activities and different issues each working group faced and solved. Following this introductory chapter, five chapters are devoted to the different working groups. Each chapter was prepared by the working group coordinators, based on the contributions of different participants from several member countries. These chapters generally include the hydrological challenges each working group faced, project organization and development, an outline of the activities undertaken by each group, and several selected examples of the research output for each working group. A simple summary for phase I, and some recommendations and suggestions for the next phase are given in chapter 7. General conclusions for the first phase of Asian Pacific FRIEND are represented in the last chapter.

Abbreviations related to this report are given in Annex 1. Contact details for the working groups and member countries are listed in Annex 2. The rivers catalogued in the four volumes of the Catalogue of Rivers are listed in Annex 3, and publications produced by Asian Pacific FRIEND participants are provided in Annex 4.

Chapter 2: Working Group 1: Asian Pacific FRIEND Water Archive


2. WORKING GROUP 1: ASIAN PACIFIC FRIEND WATER ARCHIVE

2.1 Introduction The establishment of the Asian Pacific FRIEND Water Archive is one of the two

major projects that commenced under the first phase of Asian Pacific FRIEND. The purpose of the archive as described in UNESCO (1999) was to contain the river runoff and other hydrometeorological and water resources related information collected for: • The Catalogue of Rivers for Southeast Asia and the Pacific, • Asian Pacific FRIEND research projects, and • Other IHP related activities of member countries.

The intention was that data for river basins described in the published volumes of the

Catalogue of Rivers for Southeast Asia and the Pacific would be contributed to the archive by the countries of the region. This would then form a core of data that would be available to projects to be undertaken under the second major project of Asian Pacific FRIEND: ‘Flood and Low Flow Research’. In turn these projects would contribute to the Water Archive any additional data collected during the course of the project. As a result, over time an expanding body of data would become available for other research projects carried out within the region. It is also hoped that the countries in the region will see the benefits of the collaborative research being carried out under Asian Pacific FRIEND, relax restrictions on access to data and contribute additional data to the archive. Table 2.1 Working Group 1 projects (in addition to establishing the Water Archive) Project Number

Title Contact person

1.1

Information on New Zealands Freshwaters: Water Resources Archive

Charles Pearson NIWA, New Zealand

1.2

Development of Internet GIS based Water Archive System

Keho Kim Uni System Engineering Consultants, Republic of Korea

1.3

Establishment and Dissemination of Water Archive

Dr Mohd. Fadhlillah Hj. Mahmood Dept of Irrigation and Drainage Malaysia

1.4

Directory of Asian Pacific River Basins Ross James Bureau of Meteorology, Australia

1.5

Development of Hydrologic Data Base to Describe the Regionality

Assoc. Professor Akihiko KondohChiba University, Japan

1.6

Development of GIS Water Archive System in Merapi-Yogyakarta Basin

Dr Dwikorita Karnawati Gadjah Mada University, Indonesia

The process of seeking research proposals to be undertaken as part of Asian Pacific

FRIEND has been described in Chapter 1. As a result of this process a total of six proposals were received that were broadly related to database development or management of, and access to, data and information. Another feature of these proposals



was that they were not collaborative in the sense that they did not involve people in a number of countries collaborating on a hydrological development or on research into a hydrological issue. However, while all of the proposals except two had objectives quite specific to the country undertaking them, there was considerable potential for the technology being developed to be of value in the further enhancement of the Water Archive or, for access to data for Asian Pacific FRIEND projects to be improved. Consequently, the proposals were placed in Working Group 1 so their progress could be monitored and encouraged. The titles of the projects are shown in Table 2.1 and a more complete description of the objectives of each project may be found in UNESCO (1999).

As the projects did not involve collaboration between countries, communication

between the working group members has been minimal and primarily consisted of enquiries regarding progress so that working group progress reports could be prepared. 2.2 Achievements

This section provides a description of the development of the Asian Pacific FRIEND Water Archive. It also includes a summary of information that is available about progress in the other projects in the working group. Asian Pacific FRIEND Water Archive

The development of the Asian Pacific FRIEND Water Archive was the primary objective of the working group. Related to this primary objective were a number of sub-objectives as follows: • To assist with the establishment of the Central Node at the Regional Humid Tropics

Hydrology and Water Resources Centre for Southeast Asia and the Pacific in Malaysia.

• To document the preferred standards and guidelines for the provision of data and other information to the Water Archive by participating countries.

• To obtain and prepare data and make it available from the water archive nodes. • To prepare guidelines for the operation of the country nodes being established to

provide access to the data for the host country. • To work through the Regional Centre to assist countries to establish and operate a

Country Node.

The primary objective has been achieved with the establishment of the Water Archive. The archive is not a data archive in the traditional sense of a structured database management system for storing, managing and providing access to data. Its primary focus is to provide easy access to data from a wide geographical area by users who may also be widely separated geographically. It is also important to note that the water archive is not intended to be a repository of original data. The ownership of the original data and responsibility for its archival always remains with the source country. Consequently, access to the data rather than robust and secure data archival has been emphasised in the Water Archive development.

In order to provide the desirable level of access to data, a distributed system based on the Internet has evolved. The water archive consists of a series of nodes linked via a home page that acts as a gateway to the archive. The use of nodes, which can be located in separate countries, provides each country with the opportunity to manage and control access to their data. The individual country nodes are linked to a central node where data



from countries that do not wish to establish an individual node are stored. Nodes may be created over time in response to changing circumstances in participating countries. The central node acts as a gateway or portal to the other nodes thus giving the impression that the Water Archive is a single entity. The structure of the archive is shown schematically in Figure 2.1 and is described in more detail in James and Desa (2000) and James et.al. (2001).

The Water Archive Home Page and the central node are located in Malaysia at the Regional Humid Tropics Hydrology and Water Resources Centre for Southeast Asia and the Pacific. To-date two country nodes have been established; one at Yamanashi University in Japan and the other at the Bureau of Meteorology in Australia. Data for Japan and Australia are available from the respective country node and data for all other participating countries are available from the central node. The address of the Home Page for the central node is http://htc.moa.my/apfriend/wa.

The Water Archive has been designed to provide flexibility in the way data can be accessed so that data are made available according to the wishes of the country providing it. Three forms of access are available: • Immediate download where requested data are immediately transferred to the user. • Request where a user submits an online request and the data are made accessible to

the requestor on-line after the request has been cleared by staff at the Regional Humid Tropics Hydrology and Water resources Centre.

• Link where a link is provided to a third-party web site where the data may be accessed.

The use of these methods of data access is described in more detail in James et.al. (2001).

Figure 2.1 Schematic diagram of Water Archive structure

Data holdings have been slowly increasing as participating countries realise the benefits of making data available for research purposes and relax restrictions on distribution of data. Unfortunately the rate of contribution has been less than originally hoped for and the length of record and range of data types available for some river basins

W ATER ARCHIVE

HOM E PAGE

Country 1 Country 2 Country 3 Country 4 Country 5 :::: :::: Country X

W W W

Country 2 Node Data Files

Country 4 Node Data Files

Researcher connects to the W ater Archive by the W W W

Connection transferred via W W W to Nodes as needed to obtain data for different countries

Central Node Country 1 data files Country 3 data files Country 5 data files



are less than considered necessary to support regional hydrological research. The objective is to assemble long daily and monthly time series of the primary hydrometeorological data types (streamflow, precipitation, evaporation) for selected river basins in each participating country. By mid-2002 data had been received for 46 basins in 12 countries. The data are mainly of streamflow and precipitation although there are also some evaporation, temperature and wind data. Unfortunately much of the data are in short time series and are monthly values.

Comprehensive documentation detailing the preferred data formats and conventions for preparing data has been prepared. This documentation has been distributed to all participating countries and is used as an explanatory document when requests for additional data to be included in the Water Archive are made. The information in the document is also used to guide the preparation and management of data for the archive by staffs at the Regional Humid Tropics Hydrology and Water resources Centre. Additional technical documentation has been prepared describing the water archives web based interface and its maintenance. Project 1.1 - Information on New Zealand’s Freshwaters: Water Resources Archive

The objective of this project is to manage the data collected from the national climate, hydrometric and water quality networks and to provide comprehensive information about New Zealand’s climate and surface water resources (Pearson 1998). Analysis of the water quality data is being undertaken in collaboration with the USGS. Considerable progress has been made towards updating the software used to manage the databases. The updated software will provide improved access to the data with access to all databases via the Internet scheduled to be implemented during 2002. The development of the data bases and efforts to provide improved access has required a range of issues to be addressed such as; transfer of data between different data base systems, provision of and standards for metadata, ownership of data and the difficult question of charging for the provision of data. A copy of the hydrometric database has been provided to the Regional Humid Tropics Hydrology and Water Resources Centre for Southeast Asia and the Pacific for inclusion in the Asian Pacific FRIEND Water Archive. Project 1.2 - Development of Internet GIS- based Water Archive System

The objective of this project is to develop a GIS based water archival system on the Internet to provide access to both geographic and non-geographic data. A hydrologic unit code that is a function of topography is the basis of the system. This code is used to index and store meteorological, hydrological, sociological and any other related data. The river systems in Korea have been classified using this system into 10 large basins. These large basins have been further divided into 115 medium basins that have been further subdivided into 1174 small basins. The current stage of development of the database is not known. Successful completion of this project may result in a new node for the Water Archive. Project 1.5 - Development of Hydrologic Data Base to Describe the Regionality

The objective of this project is to study variations in regional hydrology using an Internet based database of hydrological and geophysical data and GIS technology. The database contains a wide range of observational data and the results of hydrological studies carried out on research catchments from around the world (Kondoh et. al. 1998, 1999). Data in the database consists of precipitation, streamflow, albedo, environmental



isotope, satellite imagery and land use change. GIS presentations of some of the data can be created. The database and presentation system have been developed using readily available open system software (Kondoh et. al. 1999) and may be accessed at the URL: http://aqua.cr.chiba-u.ac.jp/gdes/. Other projects

Projects 1.3 and 1.6 in Table 2.1 were unable to commence either due to changes in personnel at the institutions undertaking them or due to the lack of necessary funding. It was decided not to commence project 1.4 as a result of sensitivities in some countries to the provision of mapping information and the difficulties experienced in obtaining hydrological data for inclusion in the water archive. It was felt that the map information required for this project might be more readily available during future phases of Asian Pacific FRIEND. 2.3 Assessment

An overall assessment of Working Group 1 is that it has achieved its primary objective of establishing the Asian Pacific FRIEND Water Archive. The archive is operational, accessible via the Internet, simple to use and straightforward to maintain. Increased collaboration between countries as a result of the Asian Pacific FRIEND is evident in the increasing willingness of countries to contribute data to the archive. More effort is required, however, as the range and quantity of data available for river basins throughout the region is not yet as extensive as was planned or sufficient to support the research projects proposed. This situation is expected to continue to improve over time as data are made available from additional collaborative research projects and the benefits of the archive are realised. Use of the archive is difficult to monitor as much of the data are available for immediate download. As yet formal systems for monitoring access to the web pages have not been implemented.

With respect to the other projects in the working group the results have been varied. As these projects have been quite independent and the majority are specific to the country in which they were to be carried out, it has not been necessary for the working group to establish close links between them. Unfortunately, as the working group was unable to provide funding support a number of the projects were unable to commence. 2.4 Training

Training is a key component of the successful implementation of all new techniques and technologies. While training in the use of the Water Archive is not considered practical as its potential users are widely dispersed, or considered necessary due to its simplicity, training in the management of the interface software and database and of the computer server on which it operates is essential. Staff at the Regional Humid Tropics Hydrology and Water Resources Centre have an ongoing responsible for maintaining the integrity of this computer system, interface software and archive of data and for ensuring that efficient and effective access to the data via the Internet is maintained. UNESCO Jakarta Office has agreed to fund a training program to ensure that the necessary skills, particularly the information technology skills, to meet these responsibilities are available. Initial training has been undertaken and funding for ongoing training to maintain these skills will be considered on a year-by-year basis.



2.5 Further Development In common with all software and database systems there is always additional

development that can be undertaken. Further development of the Water Archive may be summarised as follows. • Making available a more comprehensive range of data for a larger number of river

basins throughout the Asia-Pacific region. This will require an increase in communication with the countries participating in the Asian Pacific FRIEND and the researchers throughout the region undertaking FRIEND research projects to convince them of the value of contributing data to the water archive.

• Expansion of the archive to include digital copies of reports, papers, conference proceedings and any other digital material that will improve the understanding of the hydrology and water resources of the region.

• Implementation of systems to assess use of the water archive by monitoring access to the various web pages that form the interface to the water archive data.

• Development of a formal data base management system to provide a more rigorous management environment for the data and other digital documentation held by the water archive. This development would require a considerably larger commitment of resources and skill during the development and then for ongoing management. Consequently, it should only be undertaken if the use of the water archive increases dramatically and the volumes of data held become unmanageable using the current system.

2.6 References Pearson, C.P. Changes to New Zealand’s national hydrometric network in the 1990s.

Journal of Hydrology (NZ) 37(1): 1-17, 1998. James, R.A. and Desa M.,M.N. Asian Pacific FRIEND Water Archive: Status Report,

Proceedings Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, November 2000, IHP technical Documents in Hydrology No 7 UNESCO Jakarta Office, 2000.

James, R.A., Desa M.,M.N. and Mohd. Shahar, S. Upgrade of the Asian Pacific FRIEND Water Archive, Proc. Int. Symp. On Achievements of IHP-V in Hydrological Research, Ha Noi, Viet Nam November 2001, IHP technical Documents in Hydrology No 8 UNESCO Jakarta Office, 2001.

Kondoh, A. and Agung, B.H. Study on areal evapotranspiration in Asia-Pacific region – Toward GIS-oriented hydrologic database for comparative hydrology. Proc. Int. Symp. on Hydrology, Water Resources and Environment Development and Management in Southeast Asia and the Pacific. Taegu, Republic of Korea, Nov 1998. IHP-V Technical Documents in Hydrology No 3, UNESCO Jakarta Office 1998.

Kondoh, A., Nakayama, D., Harto, A.B. and Runtunuu, E. Geographic Database to describe regional characteristics. Proc. Int. Symp. on Floods and Droughts. Nanjing, China, Oct 1999. IHP-V Technical Documents in Hydrology No 4, UNESCO Jakarta Office 1999.

UNESCO. Asian Pacific FRIEND. IHP-V Technical Documents in Hydrology No. 2, UNESCO Jakarta Office, 1999.

Chapter 3: Working Group 2:Rainfall-Runoff Models


3. WORKING GROUP 2: RAINFALL-RUNOFF MODELS

3.1 Introduction The Asian Pacific FRIEND provides a framework within which cooperative research

is carried out to improve the understanding of hydrological science and water resources management in the Asian Pacific Region through comparative studies of the similarity and variability of regional hydrological phenomena and water resource systems. Working Group 2 mainly aims to develop rainfall-runoff models, that can be used in data scarce basins to improve the predictability of floods and low flows and to make it possible to assess the impacts of land use changes and climate variation on floods and low flows.

General overview - general objectives, methods of working, funding situation

Comparative hydrology and water resources are areas of study in which the characteristics of hydrological processes across a region are analysed and simulated. In Working Group 2, both the differences and the similarities of the characteristics that govern the hydrology and water resources of the region have been investigated. A series of rainfall-runoff models to describe the hydrological responses of basins, including both components from natural basins and those components to assess the impacts on quantity, quality, and sedimentation resulting from water resources development, have been developed by this working group. These models can be used in small basins, dominated by rainfall-runoff processes, or large basins with complex channel and storage processes. With these models, the following hydrological processes have been examined: 1. Factors controlling floods and low flows 2. Assessment of land use changes 3. Assessment of climatic variation 4. Assessment of precipitation and river discharge measurement networks 5. Assessment of changes in sediment discharge and water quality 6. Establishment of flood and low flow forecasting systems, including flash flood

forecasting 7. Identification of urban floods and low flow dynamics 8. Transportation and diffusion phenomena of water quality and sediments

The financial support for Working Group 2 was mainly from UNESCO and MEXT

(Japan Ministry for Education, Culture, Sports, Science and Technology), and it has supported the attendance of some researchers at workshops and conferences. Organisation of research, research network, research schedule, WG meeting

Implementation of the working group commenced at the 1st Asian Pacific FRIEND Workshop in Kuala Lumpur, March 1998, where the Asian Pacific FRIEND Science Plan was presented and agreed. After a request for research proposals distributed by the UNESCO Jakarta Office to the IHP National Committees, more than 50 researchers from 10 member countries submitted their proposals to the coordinator. The details of all research proposals and the contact details of all researchers have been published both to promote information exchange and to encourage researchers to collaborate with others in the same working group. The creation of an e-mail list administered by the Regional Humid Tropics Hydrology and Water Resources Centre in Kuala Lumpur is an important way for researchers to contact each other and to be informed of activities within the Asian Pacific FRIEND. A series of workshops and meetings were organized, at which participating researchers were invited to present progress reports, encouraged to share experiences and to seek assistance from other specialists. The financial support for

Chapter 3: Working Group 2: Rainfall-Runoff Models


Working Group 2, mainly from UNESCO and MEXT, has successfully supported the participation at workshops and conferences for researchers from different member countries. 3.2 Main hydrological issues and the research projects proposed

This working group aims to develop rainfall runoff models that can be used in data scarce basins to improve the predictability of floods and to make it possible to assess the impacts of land use changes and climate variation on floods and low flows. Main research projects proposed

After the request for research proposals were distributed by UNESCO Jakarta Office to the IHP National Committees in 1998, more than 20 research proposals were submitted to the working group coordinator. These include (Contact person’s name is underlined): 1. Comparative analysis of evapotranspiration and runoff in AP region

(M. Hashino, H. X. Yao, H. Yoshida, Japan) 2. Development of modified river sediment transport model for hydrological simulation

of large, ungaged and human disturbed basins (W. Sae-Chew, Thailand)

3. Integration of rainfall-runoff model and GIS software packages for drainage simulation and graphic presentation of flooding in urban areas (T. Kitpaisalsakul, C. Sukhsri, Thailand)

4. Comparisons of ANSWERS and TOP model runoff prediction on different catchment scales (H. Pawitan, Indonesia)

5. Forecasting of flood and low flows using neural networks (M. Y. bin Mashor, R. Abdullah, Malaysia)

6. Development of modified Xinanjiang model for hydrological and water resources simulation of large and human disturbed basin (G. S. Wang, China)

7. Water fluxes and pathways in river basins (R. A. Woods, New Zealand; R. Grayson, Australia)

8. Linked precipitation runoff modelling system for mountainous catchments (R. P. Ibbitt, New Zealand)

9. Assessment and modification of available hydrological computer models to suite local condition and possible application for the regions (Ismail bin Hj. Abustan, M. N. Hj. M. Desa, Malaysia)

10. Development of rainfall-runoff model using GIS and satellite images information (K. Yoon, G.-B. Yeon, Korea)

11. Development of modified TOP model and Muskingum-Cunge method for hydrological and water resources simulation of large, ungaged and human disturbed basins (K.Takeuchi, H. Ishidaira, K. Sunada, Y. Sakamoto, Japan)

12. Estimation of lumped model parameters from basin characteristics without runoff data (S. Kazama, Japan)

13. Assessing the performance of a topographic-based model, TOPMODEL in simulating runoff responses in tropic regions for basins in Malaysia (L. K. Sing, M. N. bin M. Desa, Malaysia)

14. Development of a WWW-based flood forecasting system using a distributed catchment model and its application in some selected Asian river basins



(S. Herath, R. Jha, D. W. Yang, D. Dutta, A. Pathiraman, K. Musiake, Japan; A. Pineda, P. Castro, Philippines; U. Weesakul, T. Sukhapunnaphan, Thailand; H. M. Hien, Vietnam)

15. Application of 2-dimensional finite element model for runoff prediction (H. Nakamura, Japan; D. Karnawati, Indonesia)

16. Comparative hydrological study on stable isotopic compositions of rivers in the Asia Pacific region (T. Tanaka, J. Shimada, Japan)

17. Comparative study of the characteristics of spatial and temporal variability of rainfall in headwater mountainous areas in Asia Pacific region (K. Koichiro, Japan; S. Salim, Malaysia; A. D. Rampisela, Indonesia)

18. Quantitative analysis of effects of reforestation in AP region (S. Kobatake, E. Shimojima, Y. Shimizu, Japan)

19. Rainfall-runoff modelling and uncertainty analysis (J. Xia, China; K. Takeuchi, S. P. Zhang, Japan)

20. Detection of global climate variation from river discharge and application of river discharge information for the improvements of global climate prediction (T. Oki, K. Musiake, S. Herath, T. Nakaegawa, Japan)

21. Development of modified HORTON or TANK model, Nash Instantaneous Unit hydrograph method and continuous Muskingum method for hydrological and water resources simulation and forecasting of large and human disturbed basins (X. Tao, X. M. Feng, China)

22. Rainfall-runoff computations for small and medium river basins in Vietnam (L. T. Anh, T. Thuc, Vietnam)

23. Reservoir sedimentation computations (N. K. Dzung, C. D. Du, Vietnam)

3.3 Scientific Achievements and Assessment

3.3.1 Main achievements and practical applications Introduction – regional needs, focus of research, and potential applications

As one example of the Asian Pacific FRIEND activities, a workshop on Mekong Basin Studies was successfully organized by Working Group 2 in Bangkok, January 2000. As the largest international river in the region, the Mekong River studies received unprecedented attention by Asian Pacific FRIEND members. At this workshop, a range of modelling studies on the Mekong River were presented, a number of problems related to the Mekong River basin were raised and ways to deal with them were considered. In addition, a wealth of information pertaining to subjects such as: • how to simulate large catchments, • how to incorporate into models land use change as a dynamic process linked to water

resources, • what techniques can be used to derive physical catchment characteristics, and • what different types of models are required for simulating diverse hydrological

processes, were found and widely discussed. The outcomes have successfully stimulated hydrological research in the region, and have greatly contributed to hydrological science. Main achievements

Before rainfall-runoff models with good performance are developed and applied in the Asian Pacific Region, it is necessary to investigate the similarity and difference of the



hydrological characteristics of the region. For this purpose, the specific mean annual discharge against catchment area for many rivers in the region was compared, as shown in Figure 3.1. The largest specific mean annul discharge (>6.0 m3/s/100km2) appears in humid regions such as Indonesia, Japan, Lao, Malaysia, New Zealand, Papua New Guinea, Philippines, and Vietnam. The second largest values (3.0-5.0 m3/s/100km2) were found in Southern China and Korea. The lowest specific mean annual dischares appear in Australia, one of the most arid countries in the Asian Pacific FRIEND region. Unexpectedly, the specific mean annual discharges in Thailand are also quite small (<2.0 m3/s/100km2). This may be because of over-withdrawal of water from the rivers in Thailand.

Figure 3.1 Specific mean annual discharge against catchment area. Data have been grouped according to their annual basin precipitation

Data from the Asian Pacific Water Archive has been used in a water balance study of

the Monsoon Asia (Kondoh et al., 1998). The study uses the water balance to classify the hydrological region. Four components of water balance; the potential evapotranspiration by the Priestley and Taylor method, actual evapotranspiration by Thornthwaite’s book-keeping method, soil moisture and water surplus and deficit have been estimated in Monsoon Asia. Figure 3.2 shows the resultant map of water surplus and deficit classified into seven regions, in which ATD stands for the annual total deficit of water and the definitions of the regions area: - Region A: water surplus all year around; - Region B1: water surplus with deficit in some months (ATD <200 mm); - Region B2: water surplus with deficit in some months (ATD >200 mm); - Region C1: water deficit with surplus in some months (ATD <200 mm); - Region C2: water deficit with surplus in some months (ATD >200 mm). - Region D1: water deficit all year around (ATD <200 mm); - Region D2: water deficit all year around (ATD >200 mm);

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10 100 1000 10000 100000 1000000

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Figure 3.2 Hydrological regions in Monsoon Asia

Several kinds of rainfall-runoff models, able to be applied to small basins dominated by rainfall-runoff processes, and large catchments dominated by complex channel and storage processes, have been developed and calibrated. One of the first models developed by members of the working group was based on the Tank model (Nawarathna & Kazama, 1999; Kazama et al., 2000). This model was used to study 5 basins in the Southeast Asian region, including: 1. The Chu basin in Vietnam with a drainage area of 2,105 km2, 2. The Thac Buoi basin in Vietnam: 2,313 km2, 3. The Sirikit basin in Thailand: 13,130 km2, 4. The Srinagarind basin in Thailand: 10,880 km2, and 5. The Lam Dom basin in Thailand: 3,363 km2.

All the basins are covered mainly with forest and have distinct dry and wet seasons. The Tank model was used in these five basins from 1993 to 1995 and the numerical calibration obtained 16 Tank model parameters to compare with geographical conditions supported by GIS analysis. The results showed that there are high correlations between the parameter of the surface flow from the first tank (Z11) and the amount of waste and vacant land (WVL), between the supply of moisture from the soil to base flow (B3) and the consolidated deposit area (CD) in the third tank, and between the dam lake area ratio and base flow contribution (A4) in the fourth tank. However, the second tank has weaker correlations for all combinations of parameters because it has only a small impact on total runoff. Figures 3.3 and 3.4 show two examples of the parameter correlations and Table 3.1 shows all relationships between all parameters and geographical conditions found by multi-regression analysis. All Tank model parameters can be estimated from the results and the Tank model can generate a hydrograph in an ungauged basin. Figure 3.5 indicates simulated results by this method with observed data for the Chu basin. This study shows



that there is a strong possibility that GIS data can be used to define runoff models that do not need calibration and are characteristic of Southeast Asian basins.

Figure 3.3 Relationship between basin factors and the Tank model parameters (CH: Chu, TB: Thac Buoi: Vietnam) (SR: Sirikit, SN: Srinagarind, LD: Lamdom: Thailand)

Figure 3.4 Tank model with 16 parameters used

CH

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Table 3.1 Multi-regression derived equations for estimating Tank model coefficients from Basin Factors, where the basin factors are expressed as a ratio of basin area. FL: Forest land, WVL :Waste and Vacant area, FAL :Farming area, CD :Consolidated Deposition Area, UCD :Unconsolidated Deposition Area, DLA :Dam lake area

Pij FL WVL FAL Slope Length

Basin Area

CD UCD DLA

A11 0.0037 0.0145 -0.0207 -0.0020 0.0000 -0.0024 0.0024 -0.0159

A12 0.0030 -0.0323 -0.0025 0.0006 0.0000 -0.0026 -0.0057 0.0037

B1 0.0023 -0.0081 0.0149 0.0024 0.0000 0.0005 0.0119 -0.0023

A2 0.0030 0.0056 -0.0135 0.0006 0.0000 -0.0031 -0.0033 -0.0063

B2 0.0007 0.0013 0.0050 -0.0005 0.0000 0.0019 0.0079 -0.0041

A3 0.0003 0.0052 -0.0007 0.0013 0.0000 -0.0029 0.0035 -0.0051

B3 0.0005 -0.0024 0.0007 0.0005 0.0000 -0.0002 -0.0036 0.0039

A4 0.0057 0.0000 -0.0305 0.0001 0.0000 -0.0034 -0.0021 -0.0175

Z11 0.4855 -1.7689 5.7456 1.5092 -0.0263 -0.2542 8.4287 -4.9842

Z12 -0.0017 0.4961 1.8823 0.0966 -0.0030 0.2463 2.9056 -1.6667

Z2 0.1449 0.4515 0.3674 0.0020 -0.0007 0.0560 0.3670 -0.1478

Z3 0.1511 0.0437 -0.2455 -0.1521 0.0023 0.2215 -0.2041 0.1361

Chu basin

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Figure 3.5 Comparison between observed data and Tank model estimates using parameters derived from the equations given in Table 3.1.



With the introduction of increased computing power and the need for more spatial detail in the results, several grid-based spatially distributed models were developed. Two of these, the PB and GB models were developed for simulating the hydrological processes in large river basins (Jha et al., 1998; Yang et al., 1998; Herath et al., 1999). Hydrological modelling using 1 km DEM data sets has been carried out in the upper Chao Phraya basin of Thailand and the upper and middle reaches of the Mekong basin, covering 100,000 km2 and 400,000 km2 respectively. The basins to which the model was applied are shown in Figure 3.6 (left hand panel). In these models, evapotranspiration, infiltration, groundwater flow and river flow were simulated on a continuous daily basis.

For each sub-basin within each catchment the corresponding daily values were aggregated into annual means and compared with the measured data. The comparisons for each of the 21 sub-basins in the Chao Phraya catchment are shown in Figure 3.6 (centre panel). In the legend the simulated runoff corresponds to results from the PB model with and without the use of the surface storage component (“with SS” and “no SS” in the figure legend). The major findings of the study can be summarized as follows: 1. The most important factor for determining the accuracy of flow simulation was the

rain gauge density, with best results obtained in Japan where the rain gauge density is 3-8/1000 km2 compared with 0.1-1/1000 km2 in Thailand and .03-.2/1000 km2 in the Mekong basin.

2. The effective resolution of regional land use data is around 20-40 km2, similar in order to that of soil property information. Therefore, the heterogeneity of land classifications cannot be represented adequately below this spatial resolution.

3. While the river flows can be simulated well by the two different simulation models, the evapotranspiration estimates varied in some catchments. As the groundwater and evapotranspiration losses can be complementary, it is difficult to verify each variable adequately as the amount of data available, especially spatial distribution of groundwater, is not adequate. Focusing on evapotranspiration estimates may lead to better quantification of hydrological cycle.

4. Figure 3.6 Study areas (the Mekong River basin left, the Chao Phraya River basin right in the left hand panel) and the annual water balance in Chao Phraya basin, Thailand (Centre). The centre graph shows for each sub-basin marked on the map to the right, the annual measured and simulated water balance components.

Y1C

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More recently, with the greater access to DEM data, more physically based models better able to use the new information have been developed. One of these models, the physically-based distributed hydrological model, BTOPMC, developed by the working group at Yamanashi University, was successfully tested and validated on both small and large river basins. The large basins used include the Fuji River in Japan, the Mekong River, and the Yellow River in China (Takeuchi et al., 1998; Ishidaira et al., 2000). Combined with this study, mapping of regional spatial data such as land use and geology was also carried out. This model has been developed as a rainfall-runoff model for application to various basins as a common measure for comparative hydrological studies. This model is a modified TOPMODEL combined with the Muskingum-Cunge channel routing method, and it is suitable for use in large, data-poor, basins. Figure 3.7 shows the result of application of the BTOPMC to the upper Kali Brantas basin in Indonesia (5,100 km2). Elevation data on an approximately 1 km grid were used from the GTOPO30 DEM, and monthly precipitation data from 21 stations for 1951-1979 were used in this simulation. The model parameters were identified through calibration with data from 1951 to 1952. The results of the validation from 1953 to 1972 show reasonable agreement with observed discharge. However, the simulated hydrographs did not fit the observed ones well after 1973 and this is attributed to the effects of flow regulation by reservoir operations. Thus, in order to simulate the streamflow more accurately, it is necessary to incorporate the effects of reservoir operation into model applications.

Figure 3.7 The simulated (smooth line) and observed (square symbols) monthly hydrograph at Jeli, Kali Brantas.

In a similar development, New Zealand has developed a modelling system called TOPNET that allows large basins to be modelled using a sub-basin structure rather than a grid-based structure. This model was applied to data from the remote Nam Gnouang River (Herath and Dutta, 2000, pp.81-91), a tributary of the Mekong River in Lao PDR.

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Karaangkates Karaangkates DamDam(343.0 x 106m3)

LahorLahor DamDam(36.1 x 106m3)

WlingiWlingi DamDam(24.0 x 106m3)

Calibration (1951-1952): e=86.0% r=0.91Validation (1953-1972): e=63.5% r=0.88; (1973-1979) e=-50.7% r=0.82

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Karaangkates Karaangkates DamDam(343.0 x 106m3)

LahorLahor DamDam(36.1 x 106m3)

WlingiWlingi DamDam(24.0 x 106m3)

Calibration (1951-1952): e=86.0% r=0.91Validation (1953-1972): e=63.5% r=0.88; (1973-1979) e=-50.7% r=0.82



Results were presented at the Mekong Basin Modelling Workshop held in Bangkok in January 2000. Figure 3.8 shows the fit obtained to 12-hourly data for this catchment of about 2400 km2 and Figure 3.9 shows the sub-basin structure derived from the GTOPO30 DEM used to build the model’s spatial structure.

Figure 3.8 The result of calibrating the TOPNET model to the Nam Gnouang catchment in Lao PDR so as to minimise the difference in the measured and simulated flow values. The measured data are the triangular symbols, while the simulated data form a continuous line.

Figure 3.9 Nam Gnouang sub-basins, channels and channel segments (straight lines) used in the model representation. Sub-basins are defined by locations on the channel network through which at least 160 upstream pixels drain.

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Another more recent example is the Distributed Time Variant Gain Model (DTVGM) developed by Xia et al. (2001) and applied to arid and semi-arid regions. The runoff generation process and flow routing is combined by soil moisture in the DTVGM model. In this model, the vertical direction is divided into two layers: one is surface flow, the other is the subsurface flow. Surface flow is routed using a kinematic wave approach. Figure 3.10 shows the comparison of the simulated and observed hydrographs at mountainous Heihe River basin with a basin area of 130,000 km2 and 35 tributaries in China. The results show that the DTVGM model can capture the main features of the runoff generation in arid or semi-arid catchments.

Figure 3.10 Comparison of the simulated and observed hydrographs in Heihe River basin of China 3.3.2 Training and capacity building Review of training provided

Training and capacity building in Working Group 2 are mainly provided in the form of workshops and technical meetings. In collaboration with the other four working groups, several combined workshops and technical meetings have also been successfully organized from 1998. The main workshops and international symposia held are listed as follows: • 1st AP FRIEND Workshop on Science and Water Archive of the Comparative

Hydrology and Water Resources, Kuala Lumpur, Malaysia, Mar. 20-21, 1998. • 2nd AP FRIEND Workshop on ENSO, Floods and Droughts in Southeast Asia and the

Pacific Hanoi, Viet Nam, Mar. 23-26, 1999. • International Symposium on Floods and Droughts, Nanjing, China, Oct. 18-21, 1999. • International Symposium on Fresh Perspectives on Hydrology and Water Resources

in Southeast Asia and the Pacific, Christchurch, New Zealand, Nov. 21-24, 2000. • AP FRIEND Workshop: Mekong Basin Studies. Bangkok, Thailand, Jan. 24-26, 2000. • International Symposium on Achievements of IHP-V in Hydrological Research. Ha

Noi, Viet Nam, Nov. 19-22, 2001.

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Achievements in capacity building

With the successful holding of the international symposia, workshops and technical meetings, the research results achieved by the working group have been disseminated to the local research communities. The participation of many researchers from developing countries has made a great contribution to the capacity building in those member countries. 3.3.3 Contribution to the scientific community Contribution to the local scientific community

Working Group 2 has been and will continue to be successful in transferring the results of the research to both the national and regional scientific communities in the region. As an example, at the national level, the Workshop on Mekong River Studies, successfully organized by the Mekong River study group of Working Group 2 in January 2000 enabled the Asian Pacific FRIEND members from Thailand, Vietnam, Lao, China, New Zealand, and Japan to meet and present their results in the field of model studies related to the Mekong River (Herath & Dutta, 2000). Delegates from the Mekong River Commission (MRC) in Cambodia, the Royal Irrigation Department of Thailand, and the Asian Institute of Technology also participated in the workshop and presented their views and experiences on the Mekong River basin and its water resources management. Many of the delegates commented on the value they had gained from sharing the results of their Mekong River studies with each other. Although the exchange between the Asian Pacific FRIEND and local organization is still in the early stage, the strong enthusiasm from both sides was impressive. There is a strong likelihood that the outcomes of this workshop will be applied by the local water resources management authorities. Contribution to global scientific community

Although on-going effort is required to disseminate the results of the research on AP FRIEND through more activities, past efforts such as publishing reports and organizing conferences and workshops have been very effective in disseminating research results to a wide audience in both the Asian Pacific Region and to the global scientific community. The working group also has links with other regional and international research programmes. Examples include the link between Working Group 2 and GEWEX/GAME in Japan, China, Thailand, and Indonesia. 3.4 Summaries and Recommendations Achievements and assessment

The main progress and achievements in hydrological research resulting from Working Group 2 are: • The development and application of rainfall-runoff models, • The analysis of the hydrological consequences of climate change, and • The comparison of the hydrological characteristics of rivers in the Southeast Asia and

the Pacific Region.



Recommendation for phase 2 More cooperation among researchers is required in phase 2, which would benefit the

development objectives in Southeast Asia and the Pacific region. The establishment of inventories of FRIEND research basins and the related database will further improve the development and management of the regional water resources and will also strengthen the comparative hydrology research in the Asian Pacific FRIEND region. The development of different rainfall-runoff models and the software to apply these models are also significant for local development in the region. Increased collaboration between working groups should be encouraged and UNESCO may provide part of the financial support for this kind of collaboration. This kind of collaboration may include both co-organizing conferences and working together on common projects related to local hydrological studies. Increased collaboration between working groups will also help with the development of regional initiatives for IHP-VI with its emphasis on more integrated approaches to river basin research. 3.5 References Herath, S. and D. Dutta (2000). Mekong Basin Studies, Proc. AP-FRIEND workshop,

INCEDE Report 19, pp.164. Herath, S., Yang, D., and K. Musiake (1999), Description of catchment hydrologic

response using Catchment area function, IAHS publication no. 54, pp. 61-70. Ishidaira, H., Takeuchi, K., and Ao, T. Q. (2000). Hydrological simulation of large river

basins in Southeast Asia. Proc. Fresh Perspectives Symposium, 21-24 Nov., 2000, Christchurch, New Zealand, pp.53-54.

Jha, R., Herath, S., and K. Musiake (1998). Application of IIS distributed hydrological model (IISDHM) in Nakhon Sawan, Thailand, Annual Journal of Hydraulic Engineering, Vol.42, JSCE, pp.145-150.

Kazama, S., T.L. Trung, Y. Yokoo and M. Sawamoto (2000), Study on construction of lumped model without runoff data, Proc. 12th congress the APD/IAHR, Vol.3, pp.879-888.

Kondoh, A., Tsujimura, M. & Kuraji, K. (1998). Construction of world basin water budget data base. In: Proc. 1st Asian Pacific FRIEND Workshop, Data Archive and Scientific Methods for Comparative Hydrology and Water Resources. Kuala Lumpur, Malaysia, 20-23 March 1998, pp.69-75.

Nawarathna, NMNS B. and S. Kazama, Analysis of the relationship between water balance and basin characteristics, Water Resources Journal, ESCAP/UN, No.202, pp.24-38, 1999.

Takeuchi, K., Ao, T. Q., and Ishidaira, H. (1998). Introduction of block-wise use of TOPMODEL and Muskingum-Cunge method for the hydro-environmental simulation of a large ungauged basin. Hydrol. Sci. J., 44(4), 633-646.

UNESCO (1995): Catalogue of Rivers in Southeast Asia and the Pacific, Vol. 1, (Eds.) Takeuchi, K., Jayawardena, A.W. and Takahashi, Y., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 291 pp.

UNESCO (1997): Catalogue of Rivers in Southeast Asia and the Pacific, Vol. 2, (Eds.) Jayawardena, A.W., Takeuchi, K. and Machbub, B., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 285 pp.

UNESCO (2000): Catalogue of Rivers in Southeast Asia and the Pacific, Vol. 2, (Eds.) Hidayat, P., Jayawardena, A.W., Takeuchi, K. and Lee, S., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 268 pp.

UNESCO Jakarta Office (1999): Proceedings of the 1st Asian Pacific FRIEND



Workshop: Data archive and scientific methods for comparative hydrology and water resources, Kuala Lumpur, Malaysia, 20-23 March 1998, IHP-V, Technical Documents in Hydrology, No. 1.

Xia J. (2001). A system approach to real time hydrological forecasts in watersheds, Water International, 27(1), 87-97.

Yang, D., Herath, S., and Musiake, K. (1998). Development of a geomorphology-based hydrological model for large catchments, Annual Journal of Hydraulic Engineering, Vol.42, JSCE, pp.169-174.

Chapter 4: Working Group 3: Statistical and Stochastic Models


4. WORKING GROUP 3: STATISTICAL AND STOCHASTIC MODELS

4.1 Introduction Objectives

The objectives of this working group were: • To compare regional characteristics of flow regimes through the assessment of long

term changes and the discrimination of similar hydrological zones, and • To develop statistical and stochastic models which can be used for flood and low flow

prediction as well as hydrological design in the Region. Working group activities

Since 1997 the following activities have been carried out to achieve the objectives: • Interaction among the working group members consisted of correspondence such as

emails, letters and face-to-face meetings when the opportunity arose; • Meetings of a number of the members of the working group were generally held in

conjunction with other meetings in the Region such as the annual meeting of the Regional Steering Committee (RSC) and workshops and symposia, and

• A working group meeting to write up the final results.

The cooperation between the respective countries and researchers contributed greatly to the achievement of the task. The researchers requested data from many organizations and the supply of hydrological, topographical and other data from these organizations made the research in this report possible.

Funding and other scheduling issues

Each individual researcher carried out their projects using their own funds. Funding for the participation of the researchers in RSC workshops and symposia was achieved through UNESCO and government funds from Japan and other countries. This did not always allow all working group members to interact with others, as it was not always possible for many members of the working group to be at the same meeting.

Research Procedure adopted

River basins in the region were reviewed and surveyed for the comparative analyses and then various research steps were performed to accomplish the above objectives as follows: • Collection of hydrological statistics and information from various countries and

researchers in the Region; • Assessment of regional characteristics of flow regimes from the statistical and

stochastic assessment of long term variability; • Improvement of statistical and stochastic models by comparison with existing models

in the Region; and • Establishment of Asian Pacific FRIEND statistical and stochastic models for flood

and low flow hydrological design.

The research programme was developed by asking researchers within the Region to nominate research projects that could be performed in the first phase of Asian Pacific FRIEND. Fourteen projects from six countries were nominated and these are included in the IHP Technical Documents in Hydrology No2, UNESCO Jakarta Office, 1999.



4.2 Summary of Achievements

4.2.1 Data collection and Verification Different researchers used a variety of data sets, which encapsulated those included in

the Asian Pacific FRIEND Water Archive. Other sources of data included regional databases of both rainfall and stream flow data as well as data bases on the Internet such as the Global Runoff Data Centre (http://www.bafg.de/grdc.htm). Table 4.1 shows the number of catchments, number of countries and length of records used for their analyses.

Table 4.1 Catchments and Length of Records used in research Researcher No of catchments used No of countries Record Length (yrs)Daniell 154 13 10- 100 Lee 30 11 10-65 Liang 16 2 20-50 Ujihashi 6 6 24-40

Different researchers used different catchments. Table 4.2 shows the variety of

catchment characteristics that were assembled to develop regional relationships. Area, river length and rainfall were the most used parameters.

Table 4.2 Catchment Characteristics Examined Researchers Variables Daniell et al Lee Liang Ujihashi Others Area xxxx xxxx xxxx xxxx Rainfall xxxx xxxx xxxx xxxx xxxx % Agriculture xxxx % Forest xxxx Population xxxx % Urban xxxx Distance of Catchment to Ocean xxxx River Length xxxx xxxx xxxx xxxx Latitude xxxx Longitude xxxx Slope xxxx xxxx Catchment Shape factor xxxx xxxx Channel slope xxxx xxxx % Water/Swamp/Paddy xxxx % Other xxxx Terrain xxxx Min Elevation xxxx Elevation xxxx Max Elevation xxxx Av. Temperature xxxx xxxx % Undulating Xxxx % Rice xxxx % Mountain xxxx River width xxxx xxxx %Flat xxxx SOI xxxx



4.2.2 Principle Characteristics for Asian Pacific Region The results from Daniell et al (2001) suggest that the following characteristics are the

most influential in estimating the annual peak streamflow response of an ungauged catchment; Catchment Area, Percentage Urban, Rainfall, The Minimum Elevation, Percentage Rice Fields, Percentage Agriculture, and Percentage Flat Land. The following characteristics were also found to be the most influential in estimating the average monthly streamflow quantiles response of an ungauged catchment; Catchment Area, Percentage Forest, Percentage Agriculture, Percentage Water/Swamp/Paddy, Average Rainfall, and Catchment Population.

Data sets were subdivided into regions as an adequate streamflow prediction could not be achieved when the entire data set was treated as a single region. The results of the Daniell et al. (2001) research suggest that catchments be grouped using the Region of Influence approach followed by a streamflow clustering process based on Hosking’s H-statistic. However, the emergence of Artificial Neural Networks seems to provide a method of grouping catchments but this was only effective in some cases.

Lee described principle components for discrimination of hydrological zones. Eleven variables were used to describe three distinct factor groups which were climate, topography and hydrology. Discriminant analysis in addition to the factor and cluster analyses was adopted to show clearer results in zoning distinct hydrological characteristics in the region. Variables for these analyses were Catchment Area, River Width, Elevation, Channel slope, Shape factor, Precipitation, Temperature, Discharge and Specific Discharge. Four hydrological zones were found in the region, these being the humid tropical zone of cluster 1, warm maritime zone of cluster 2, continental zone of cluster 3 and an outlier zone of cluster 4. Daniell also used Andrew’s curves for defining hydrological zones but only with limited success. 4.2.3 Modelling techniques used

A variety of techniques were used as shown in Table 4.3. The various inter relationships of using specific approaches for both low and high flows were demonstrated by Daniell et al.(2001) and Lee (2001). Statistical frequency distributions of the data sets were examined to discover whether there was a flow-based relationship between the various data sets. Monte Carlo techniques in the process of Probability Weighted Moment analysis of Liang et al. (2000a) and for the measurement of similarity of homogeneous regions by Daniell et al. (2001) were also used.

For the generation of flow estimates a variety of techniques were used ranging from autoregressive models, statistical equations from multiple correlation and artificial neural networks.

Lee’s Research Results

Lee (2001) determined similar hydrological zones and their rainfall-runoff characteristics in Southeast Asia and the Pacific river basins by the comparative multivariate statistical analyses and discriminant analyses. Factor analysis was firstly applied to identify the structure of climate, topographical and hydrological variables in 30 river basins of 11 countries in this region. Cluster and discriminant analyses were then used to partition river basins in the region into several zones based on the similarity of basins for typical factors and to find their hydrological characteristics. As a result of



comparative analyses, river basins in the region can be partitioned into four hypothetical zones. These included a humid tropical zone, a warm maritime zone, a continental monsoon zone and an outlier zone. The rainfall-runoff characteristics in each zone were obtained by comparative statistical analyses. Their similarities and differences were then examined according to regional hydrological conditions. Table 4.3 Modelling Methods used

Methods Researcher Multiple

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Figure 4.1 shows the dendrogram, in which h indicates the relationships between the various river basins such as Australia 1 (A1), China 1 (C1), Japan 1 (J1)…Korea 7 (K7) and so forth with the hydrological zones I, II, III and IV.

Most of the hydrological zones showed the best frequency distributions of flows to be either a 2 or 3 parameter log normal distribution and a 3-parameter gamma distribution for rainfall and runoff.

Simulation of rainfall and runoff in each hydrologic zone by autoregressive type models such as AR, ARMA and ARIMA showed that an AR(2), AR(3) and AMA(1,1) for rainfall and AR(1), AR(3) for runoff as the most suitable models.



Figure 4.1 Dendrogram for hierarchical cluster analysis using Ward’s method Liang’s Research Results

The statistical property of robustness is important in extreme value estimation. A robust method for estimating parameters was investigated by Liang et al. (1999). By combining Huber’s M-Estimator (M-E) and the Minimum Distance Estimation (MD-E), a robust estimator for quantile estimation was designed. It was known that M-E is capable of obtaining a robust estimate of the location parameter, while MD-E is able to achieve robust estimates of the scale and shape parameters, so that the combination is able to lead a robust estimation. The statistical properties of the proposed method were tested by



Monte-Carlo simulation using data generated from a Pearson type III (P-III) distribution. It was shown that the estimator is robust and has advantages if lack of bias and effectiveness are important. The procedure presented for this study is also applicable to other probability distributions for flood or low flow analysis. In a further study, Liang et al. (2000a, 2001a) proposed a modified weighted function method which may help simplify the estimation of the coefficient of variation and the coefficient of skewness from the second-order and the third-order moments of the conventional method to the first-order moment for a P-III distribution. Monte-Carlo results indicated that the modified method possesses good statistical properties in unbiasedness, effectiveness and robustness.

Liang et al. (2000b) applied the Statistical Component Analysis (SCA) to analyze the annual runoff time series in the drought regions in the northwest of China. Statistical forecasting was also presented for the studied areas. It was shown that the SCA is suitable to fit and predict an annual runoff time series.

Liang et al. (2001b) also studied the application of multi-variable stochastic models to river flow simulation. In this study, an AR(p) was used which included the determination of the structure, the estimation of model parameters and the procedure to test the model. It was concluded through the study that AR(p) is suitable to simulate river flows of both flood events and low flows. Compared to other kinds of multi-variable models, the AR(p) has advantages in application as it is simple in structure and easy to parameterise. As an example, the model was applied to analyse the water supply risk of transferring water from the Yangtze River to the northern part of China, and reasonable results were obtained from the model.

Hua and Liang (1999, 2000) described the methods and procedures for analysing the statistical properties of extreme data. In order to estimate the design flood as well as its hydrograph under the framework of the Rational Formula for small basins, a new formula and procedure were presented by modifying the traditional Rational Formula assumptions and arithmetic. Instead of making the assumption in the general Rational Formula that the rainfall is uniformly distributed for the whole duration of a design storm, the new method modifies that assumption as: only in each time interval of the design storm hyetograph is the rainfall uniformly distributed. This extends applicability of the Rational Formula to the case where the rainfall duration is less than the basin concentration time. The new method can be applied to estimate not only the design flood peak discharge, but also to simultaneously generate the flood hydrograph. In the new procedure, the statistical properties of rainfall data are summarized, then the “index-flood” method is used to estimate the parameters in the storm formula, thus obtaining the (design) rainfall hyetograph by which the design flood hydrograph is calculated. The new formulas and procedures are applicable to small basins with geometry like an ellipse, rhombus or rectangle. Parameters related to runoff yield and flood routing can be estimated either by at-site observations or by grouping the regional data in the modified procedure. The new formula and procedure were applied to estimate design flood hydrographs for several small basins, Figure 4.2 is one of the results.



Figure 4.2 Sketch of Design Flood Hydrograph Daniell’s Research Results

The research of Daniell et al. (2001) investigated regionalisation methods using Artificial Neural Networks (ANNs) for overcoming the shortage of adequate streamflow records in the Asian Pacific Region. Daniell (1991) had investigated a number of water resource problems using neural networks and had recommended the use of this technique for regionalisation. This was done by comparing well gauged catchments to develop a method of prediction for ungauged catchments. Streamflow distributions were estimated from similar catchments by training an Artificial Neural Network (ANN) to predict streamflow quantiles for the ungauged site based on the catchment’s characteristics. Methods investigated for use in forming regions using FRIEND catchments are the Region of Influence method, Kohonen Self Organised Mapping, and cluster analysis. Once the regions were formed, L-moments were used to determine the most appropriate distribution to represent the flow values from the gauged catchments. L-moments were also used in a homogeneity test when forming the regions as a threshold to ensure the homogeneity of the regions formed. The annual peak streamflow data was represented by a probability distribution fitted to the data quantified by the 2, 5, 10, 20 and 50 year Average Recurrence Interval flows (ARIs). Linear moments were developed in order to overcome the problem of higher order moments by removing the power terms and replacing the moment derivation functions with linear combinations of probability weighted moments which are an ordered combination of the data. To estimate the appropriate distribution function that fits a data set from its linear moments an L-Moment ratio diagram, as shown in Figure 4.3, was used.



Figure 4.3 Peak Flow Moment Ratio Diagram

The catchments in Australia did not match those of other Asian sites and this is due to the large variability in Australian flows.

To assess the performance of both the estimation and grouping methods the groups formed by a region of influence approach, a clustering analysis and self organising networks were analysed by comparing the results obtained using both a power multiple regression model and Artificial Neural Networks (ANNs).

Peak Flow Modelling

The final results from the estimation of annual peak flow are presented in Figure 4.4. These results show that the Multiple Regression (power) package used to estimate the streamflow performed very poorly. The Artificial Neural Network simulator, Neuframe, however, produced an average estimation error of 333%. Both the methods are dependent on the data used and in this case the data could have been significantly improved by sourcing additional characteristics that may influence the streamflow, additional sites and more accurate measurements.

The improvement to the estimations is shown to be significant by grouping the data in an attempt to find particular sites within the database that when combined represent the nature of the streamflow response of the ungauged catchment. Furthermore the results suggest that the Kohonen Networks and the HD Cluster Algorithm perform relatively evenly with average errors of 73% and 68% respectively. The stability of each grouping method is represented by the standard deviation of the estimations to attempt to see how much fluctuation occurs when estimating for multiple sites.

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The main difference between a Kohonen matrix and the HD Cluster algorithm is the

emphasis placed on the ungauged site. In effect a Kohonen matrix is an unsupervised cluster analysis considering only the characteristics of the sites to form subgroups of the entire set and then locating the ungauged site. The HD Cluster algorithm groups the sites with respect to the similarity of their characteristics to the ungauged site (ROI) and then forms a sub group with respect to the streamflow response of the sites.

Considering this, it is a significant finding that the data suggests that even though Kohonen networks do not take into account the streamflow response of the catchments for peak flow events, the groups performed as well as the groups formed by statistical hydrology. This further emphasises the importance and capacity of artificial neural networks for use in this application.

Monthly Average Streamflow Modelling

In light of the results from the yearly peak streamflow estimation the monthly flows were predicted using Artificial Neural Networks.

The results suggest two main points that: 1. the formation of regions using the HD Cluster algorithm appears to provide more

accurate monthly average streamflow estimations than the Kohonen network groups, and

2. the most accurate predictions of streamflow quantiles for both grouping methods were gained through the use of the minimum number of characteristics defined as influential through the PCA analysis.

The results shown in Figure 4.5 suggest three main results:

1. the HD Cluster algorithm on average will perform better that the Kohonen Matrix. 2. the use of average rainfall when estimating mean streamflow is preferable, and 3. the use of minimal characteristics when estimation monthly average streamflow is

preferable to using all gathered data.

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A comparison between the mean flow predicted using the rainfall quantiles, and the 50% AEP determined using the same inputs, shows the similarity of the results and emphasises the plausibility of the predictions

Figure 4.5 Errors in Estimation of Monthly Average Mean Streamflow

The results presented display the potential of ANNs and Kohonen Self Organising Maps in improving the estimates of the flow for ungauged sites. ANNs show promise in being able to improve the estimates obtained even when applied to sparse and highly variable data but the accuracy is still not good. The most effective and efficient is the use of Artificial Neural Networks with the combination of either a Kohonen Network or a combination of traditional methods to form the HD Cluster algorithm. The HD Cluster algorithm combines the Region of Influence approach with a Homogeneity clustering algorithm to avoid the problem of assuming an inappropriate seed to form groups within the data set, followed by a back propagation trained ANN.

The results for the two methods were very similar to the HD Cluster which performed slightly better on average. However, the estimates formed from the ANNs are anticipated to improve with more research into their application.

Ujihashi’s Research Results

Ujihashi (Takase and Ujihashi, 1988; Ujihashi et al, 1990) developed a procedure of data analysis and synthesis that was based on the concept of pattern recognition. Ujihashi applied the model to the synthesis and analysis of monthly hydrological data. However, in order to analyse low flow regimes or droughts a short time period of measurement such as ten days, weekly or five-day record was used. The model was refined (Ujihashi, 1998) by employing the feature prediction model using feature selection through K-L expansion. The feature selection was performed to reduce the dimensionality of the patterns and to bring the intra-pattern structure of the pattern classes to the multivariate normal probability distribution. The applicability of the methodology to data analysis, generation

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and prediction as well as detection of unusual events, such as the impact of ENSO was shown. The model consists of three entities: • a pattern analysis including feature analysis, • a stochastic analysis of pattern structures, and • a data synthesis algorithm.

The schematic diagram of the model is shown in Figure 4.6. In pattern analysis, first, a given hydrological time series of N years is divided into N segments, with each segment corresponding to a geophysical year. Each segment is further divided into K objects or seasons according to K seasons in a geophysical year. As a result, the data of all N years will be divided into N×K patterns. The stochastic structure of intra-pattern is represented by a multivariate probability distribution. In order to transform the intra-pattern structure to a normal distribution and to reduce dimensionality of the pattern, two methods were used. Firstly entropy minimization and secondly orthogonal expansions are used to select features mathematically. All patterns (N×K feature vectors) obtained through the foregoing procedure must be first recognized and classified by using a clustering method ISODATA. The inter-pattern structure describes the occurrence of reference vectors in successive seasons of the time series. This dependent relationship denotes persistence among reference vectors and can be described by a first order Markovian structure.

Figure 4.6 Schematic diagram of the model

The model was applied to the Asian-Pacific region using precipitation and also

discharge data for both monthly and ten-day data. The results show that the model has high potential to extract the variable characteristic of a hydrological record. The seasonal variation of hydrological records can be described by the representative patterns that occur in a season. Moreover, the results of statistical tests shows that the basic historical statistics such as mean, standard deviation, skewness, kurtosis, lag-one autocorrelation coefficient, Hurst coefficient, are contained within the 95% confidence interval obtained from the synthetic realization. Hence the model is capable of generating a record that can be considered to possess statistics at the series level which are representative of the historical record

Pattern ClassificationPattern Classification

Pattern AnalysisPattern Analysis

Formation of Pattern VectorsFormation of Pattern Vectors

Feature ExtractionFeature Extraction

Stochastic Analysisof Pattern Structure


Intrapattern Structure AnalysisIntrapattern Structure Analysis

Interpattern Structure AnalysisInterpattern Structure Analysis

Data SynthesisData Synthesis

Generation of Reference Vector SequencesGeneration of Reference Vector Sequences

Generation of Pattern Vector SequencesGeneration of Pattern Vector Sequences

Pattern ClassificationPattern Classification























4.3 Scientific Assessment

4.3.1 Practical applications Each country requires guidelines to establish statistical design criteria for applications

such as designing for floods and low flows. It was this need which has led to many of the research activities that have been carried out.

It was also seen that there was a need to establish a consistent approach to the

establishment of criteria across the Region. This is seen as a priority due to the scarcity of data within the Region. Techniques that are robust within a data scarce environment would be able to be used by many of the countries within the Region.

It would be convenient that if a suitable regional approach was found so that adjacent

and homogeneous areas within the Region could use these results for better prediction of hydrological parameters.

Individual countries are in the process of establishing or have established sets of guidelines for the prediction of flood flows and low flows using statistical and stochastic procedures. It was not the aim of the group to circumvent these national activities. 4.3.2 Training and capacity building

Training was achieved through the performance of tasks by research students and researchers as well as by attending seminars and symposia and by adoption of procedures from different countries. The results have also been used for upgrading the knowledge of professional practitioners and undergraduate students.

Achievements in capacity building were undertaken mainly through the networking and interaction of the researchers in the various projects. This increased awareness among the various researchers of the activities being carried out in the Region has led to a better and more complete understanding of the issues involved in the research. 4.3.3 Contribution to scientific community

Training courses have been undertaken in various countries to alert the scientific community of the advances that have been achieved by the individual researchers. In some instances training course materials have been developed to allow practitioners to use these methods.

Many of the researchers have presented their results at various meetings both nationally and internationally. 4.4 Summaries and recommendations

The achievements in Phase 1 are a set of procedures and tools that enable data to be examined much more easily for the development of regionalisation methods. Further work in Phase II needs to be done with regards to low and peak flow determination.

The performance of Phase I has brought a number of researchers much closer together. From this interaction it is anticipated that a much stronger collaboration will progress into Phase II. The nominated areas in IHP VI where stochastic and statistical studies will play



a large part are: Theme 1: Global Changes and Water Resources Theme 2: Integrated Watershed and Aquifer Dynamics Theme 3: Land Habitat Hydrology; and Theme 5: Water Education and Training Recommendations

It is recommended that Regional governments, as a priority, support data collection programmes in individual countries.

Decisions on water resources will be made in the future for the sustainable development of water. For informed decisions to be made they need to be based on a comprehensive set of data. Long data sets of climate variables and streamflow need to be established to predict the consequences of man’s activities on streamflow and to manage risk. It became apparent through the research work carried by this working group that there are indeed large areas of the Region without long periods of data records.

It is recommended that a concentrated effort be made to further review the availability of data to enable a more thorough examination of the data with the regionalisation procedures that have been developed in Phase I.

It is recommended that to further progress the research in this area that applications for funding both be made at a national and international level to maintain the continued cooperation between the various members. 4.5 References Daniell, T.M. (1991) Neural Networks - Applications in Hydrology and Water Resources

Engineering, International Conference on Hydrology and Water Resources Symposium 1991, Perth, 2-4 October ,Volume 3. The Institution of Engineers, Australia Preprints of Papers pp 797-802 (National Conference Publication No. 91/19)

Daniell Trevor M, Matthew S Hunter, Martin P Faulkner, Karlson J Hargroves (2001) Using ANNs to develop Regionalisation Methods for Streamflow Estimation in SE Asia and the Pacific, International Symposium on achievements of IHP-V in Hydrological Research, November Hanoi, Viet Nam, IHP V Technical Document in Hydrology No. 8 UNESCO Jakarta Office.

Hua, J. P., and Liang Z. M. (1999). A new method in determining design flood hydrograph for small basins, Proceedings of AP FRIEND and GAME Joint Workshop on ENSO, Floods and Droughts in the 1900’s in Southeast Asia and the Pacific, Hanoi, Vietnam, pp. III 20-27.

Hua, J. P., and Liang Z. M. (2000). Construction of Runoff Model Without Discharge Data, Proceedings Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, IHP, Christchurch, New Zealand, pp. 136-142

Lee,Soontak (2001), Discrimination of Hydrologic Zones and Rainfall Runoff Characteristics in South east Asia and the Pacific River Basins, Proceeding of the international Symposium on Advanced Civil Engineering in National Unification Era, Korean Society of Civil Engineers, Seoul, Korea.

Liang, Z. M., and Hua, J. P. (1999). A robust method in flood frequency analysis, Proceedings of AP FRIEND and GAME Joint Workshop on ENSO, Floods and Droughts in the 1900’s in Southeast Asia and the Pacific, Hanoi, Vietnam, pp. III 47-54.



Liang, Z. M., et al. (2000a). A modified weighted function method for hydrologic frequency analysis, Proceedings Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, IHP, Christchurch, New Zealand, November 2000, pp. 23-31

Liang, Z. M., et al. (2000b). Statistic component analysis for annual runoff at mountain-pass stations in drought regions, J. of Hohai University, Vol. 28, No.6, pp. 11-14

Liang, Z. M., et al. (2001a). Application of weighted function method to hydrological frequency analysis, J. of Hohai University, Vol. 29, N0. 4, pp. 95-98

Liang, Z. M. (2001b). Risk analysis on water supply quantity for middle-line of south-to-north water transfer project, J. of Hohai University, Vol. 29, No. 5, pp. 95-98

Takase N. and Y. Ujihashi (1988) Stochastic synthesis of hydrology data based on pattern recognition, Proceedings of 6th Congress APD-IAHR, Vol.1 pp.213-220.

Ujihashi Y., N. Takase and K.Kamon: (1990) Analysis and Synthesis of Monthly Precipitation Data Based on Pattern Recognition, Proceedings of J.S.C.E.,No.417,Ⅱ-13, pp.43-52 (in Japanese with English abstract).

Yasuyuki Ujihashi (1998) Feature extraction model in ten days hydrologic data analysis, First APF Symposium, Kuala Lumpur, Malaysia, March 1998(unpublished).

Chapter 5: Working Group 4: Frequency Analysis Models


5. WORKING GROUP 4: FREQUENCY ANALYSIS MODELS

5.1 Introduction Frequency analysis of hydrological extremes is important in practice, for example for

flood control planning and hydraulic systems design. The aim of Working Group 4 was to conduct comparative research and to establish a standard method of frequency analysis for Southeast Asia and the Pacific Region. Activities include model selection and parameter estimation for small samples, methods for robust estimation of parameters, selection of proper extreme value frequency models and techniques for handling outliers.

Working Group 4 was intended to contribute to both the two major activities of Asian Pacific FRIEND: establishment of Asian Pacific Water Archive and flood and low flow research. As the contribution to the Archive, the working group recommends the Regional Steering Committee (RSC) and Working Group 1 to include extreme value data. As a result of research undertaken by the working group members, the extreme data will be made available to the Asian Pacific Water Archive for the other users.

The coordinator of the Working Group 4 would like to express sincere thanks to Dr. Chen Yuanfang (Hohai University, China) and Dr. Van-Thanh-Van Nguyen (Canada) who helped to finalize this working group report. 5.2 Research projects proposed

Seven projects were proposed for Working Group 4, as shown in Table 5.1. Table 5.1 Working Group 4 projects: Frequency Analysis Models

Project Project title Proposer 4.1 Regionalization of floods and droughts of

Java island Hidayat Pawitan (Indonesia)

4.2 Development of frequency analysis models for hydrologic time series data

Joesron Loebis, Dyah Rahayu Pangesti (Indonesia)

4.3 Development of Nationwide low flow frequency maps of different durations and an assessment of major historical droughts

Yoon Yong-Nam, Yoo Chulsang (Rep. of Korea)

4.4 Regionalisation of rainfall parameters in Selangor, Malaysia

Zalina bt. Mohd. Daud, Amir Hashim bin Mohd Kassim (Malaysia)

4.5 Finding appropriate methods of analysis for estimating peak flows and extreme lowflows in a medium size of river basin in tropical monsoon climates

Khamthong Soukhathammavong, Khamphene Phangviladone (Lao P.D.R.)

4.6 Estimation of extreme flood by PMP/PMF method

Dang Lang Huong (Vietnam)

4.7 Frequency analysis of Hong Kong rainfalls

A.W. Jayawardena (Hong Kong)

Additional Contributors Yuanfang Cheng (China), Van-Thanh-Van Nguyen (Canada)

WG4 Coordinator Kaoru Takara (Japan)



5.3 Achievements and Assessment

5.3.1 Main achievements and practical application Working Group 4 has collected a range of information about frequency analysis

models and methods in use in the Southeast Asia and Pacific region. A number of papers dealing with hydrological frequency issues have appeared in symposia and workshops held as IHP activities during the Phase V of IHP (1996-2001). This collection of information describes the current state of hydrological frequency analysis in the Region. However, as not all the countries joined the working group the information is incomplete. Assessment of the models crossing over countries has not been executed during the several years so that no practical application has been done through the working group activity. Consequently, the information exchange did not affect methods used in each country, though it certainly stimulated researchers doing flood and drought frequency analysis.

The Working group has collected information about frequency analysis models and methods in several countries that proposed projects, and exchanged their experiences in the Region through papers and presentations at symposia and workshops during IHP-V (1997-2001). The main findings in this group include: 1. The standard methods of the countries considered are different, depending on the

situation of the country. 2. Some countries have a standard procedure developed in the country, while others are

using traditional frequency analysis methods. 3. The Southeast Asia and Pacific region has had some difficulty maintaining continuous

hydrological observations because of wars, and this resulted in relatively short records for frequency analysis.

4. Most countries use the annual maximum series (AMS); however, the partial duration series (PDS) or peaks-over-threshold (POT) series have also been used for short records or for discharge data.

5. Return periods for flood quantile estimation are different from country to country, depending on the hydrological regimes of the river basins.

6. Regionalization techniques have been investigated in some countries. 7. Frequency analysis for lowflows is basically very primitive. No systematic approach

was found in the Region. 8. Application of resampling methods such as the jackknife and the bootstrap methods,

to frequency analysis is introduced to show the variability (or stability) of quantile estimates.

9. Probability distributions with both lower and upper bounds are also introduced, encouraging hydrological consideration of the probable maximum precipitation (PMP) and probable maximum flood (PMF). Another achievement from this working group is the establishment of an extreme-

value database that is named HEAP (Hydrologic Extremes in the Asia and Pacific region), details of which were presented at the Fresh Perspectives Symposium held in Christchurch, New Zealand, in November 2000 (Takara and Nakayama, 2000). The HEAP database, which has been established at Kyoto University, includes extreme discharge and rainfall data given in the Catalogue of Rivers for Southeast Asia and the Pacific (UNESCO, 1995, 1997, 2000) and some additional extreme-value data from some countries. The HEAP is anticipated to be a part of the Asian Pacific Water Archive and to form the basis for frequency analysis studies throughout the Region.

The coordinator has summarized frequency models and methods used in countries in



the Asia Pacific region by a questionnaire to researchers who submitted proposals to the working group and by reviewing a number of papers presented at symposia and workshops. The items investigated were: 1. Which frequency analysis models (probability distributions) are often used in the

country (or state/province/region) for flood control planning. 2. Which parameter estimation (fitting) methods are used in practice.

• MOM: Method of moments; • MLE: Maximum likelihood estimation method, • PWM/LM: Probability weighted moments/L-moments; • LS: least-squares method with some plotting position formulae such as Cunnane,

Hazen, and Weibull. • GM: Graphical method using probability papers with some plotting position

formulae such as Cunnane, Hazen, and Weibull. 3. How to assess the model. 4. Which data type is used for flood control planning, i.e., discharge or rainfall? 5. Which type of data series is used, a annual maximum series or a partial duration series

(PDS)? Note that PDS may be regarded as POT (peaks-over-threshold) series. 6. The return period used for flood control planning. 7. Frequency analysis models (probability distributions) for low flow control planning, if

any. 8. Parameter estimation methods and return periods used for low flow planning.

Table 5.2 summarizes the result of the questionnaire. Frequency analysis methods are different from country to country based on the state-of-the-art and climate conditions of each country. Though Vietnam and Lao P.D.R. did not reply to the questionnaire, the coordinator included them in Table 5.2, based on available information in papers presented in the IHP-RSC meetings: Cao et al. (2001) and Soukhathammavong (1998). China

In China, the Pearson Type III (P-III) distribution is used to describe flood and precipitation extreme data for the whole country (Chen, 1999; Chen et al., 2002). The curve-fitting method (by vision-estimation or optimization technique) uses MOM or PWM/LM for estimating the initial values of parameters. The objective function of the optimization in the curve-fitting method is the sum of square errors (SSE) or the sum of absolute errors (SAE):

SSE ,)( 20

1p

n

i

ip xx −=∆ �

=

or SAE �=

−=∆n

ip

ip xx

1

0 (1)

which is also used as a goodness-of-fit criterion. In selecting the distribution model, two aspects are usually considered: (1) goodness-of-fit criteria and (2) comparison of the characteristics of the distribution with the hydrological variables concerned. Return periods for flood control planning depend on rivers. The return periods used are usually about 20-100 years; in some cases 200 years or more is used, and in other cases even 1000 years. For example, in Shanghai it is 1000 years for the Huangpu river flood control and 50-100 years at Nanjing, while 20-50 years are used for rivers near small cities. If the Pearson-III distribution is not fitted well for the observed data in terms of the goodness of fitting, the population distribution may be changed after getting permission from the General Design Institute of the Ministry of Water Resources. Wang (1999) described methods of estimating probable maximum precipitation (PMP) and probable maximum flood (PMP) comprehensively in his book.



Table 5.2 Comparison of Frequency analysis methods Country Distributions Fitting methods Goodness-of-fit Rainfall/

Discharge AMS/PDS

China P-III Curve fitting method (vision estimation or optimization), MOM, PWM/LM

SSE, SAE

Discharge AMS (PDS for short record)

Indonesia Normal, Log-normal, Gumbel, LP-III

MOM, Gumbel’s method (with Weibull formula)

Most consistent estimates

Rainfall and discharge

AMS

Japan Gumbel, GEV, Log-normal, P-III, LP-III, GPareto

ML, PWM/LM, GM (Weibull, Hazen, and Cunnane)

SLSC, PPCC

Rainfall (Discharge is also used recently.)

AMS (Recently PDS is also used.)

Rep. Korea

P-III, Log-normal, LP-III, Gumbel, etc.

MOM, PWM Kolmogorov-Smirnov Test, Chi-Square Test, RRMSE, PPCC

Mostly rainfall

AMS for rainfall, mostly PDS for runoff

Lao, P.D.R.

Log-normal, Gumbel

MOM, GM Chi-Square Test Discharge AMS

Malaysia Gumbel MOM PPCC Discharge and rainfall

AMS

Vietnam P-III MOM (No information) Rainfall, discharge, Water level

AMS

Indonesia

Frequency analysis models (probability distributions) are often used in Indonesia for flood control planning for annual maximum series of rainfall and discharge (Joesron, 2000). Most often used is the Gumbel distribution with a graphical fitting method. Point to areal rainfall relationships were developed empirically for Indonesian conditions (during the colonial era as early development of hydraulics in Indonesia), and are known as the Melchior, Weduwen and Haspers formulae. Systematic hydrometric station networks were developed nationally during the 1970's, with some stations existing before that time. Return periods used are 100 years for large dams and 25 years for urban drainage. No systematic low flow frequency analysis method is used in the country. At present in Indonesia, there is no strict enforcement of frequency analysis standards or guidelines. Therefore, the present study and suggestions for reasonable guidelines will be very important. Considerable hydrological research and development needs to be undertaken in Indonesia and the experience from other more developed countries can assist with this. A Probable Maximum Precipitation (PMP) study is also expected to be undertaken. There have not been any guidelines developed for low flow analysis in Indonesia, as major water supply systems are only available for urban areas where the sources of water mainly come for major rivers that are perennial and the demand is still much less than the low flow conditions. Recent developments of water supply systems favour use of groundwater sources due to heavy pollution of surface water sources. Further investigation of groundwater conditions in Indonesia is required. The 7-day low flow statistics should be used for low flow planning in Indonesia, especially for domestic and industrial water supply purposes.



Japan Recently, hydrologic frequency analysis in Japan has become more systematic than

before by incorporating many candidate probability distributions, best fitting methods for them, goodness-of-fit criteria such as the standard least squares criterion (SLSC) and the probability plot correlation coefficient (PPCC), and the stability of T-year events (quantiles) estimated by the re-sampling methods such as the jackknife and the bootstrap methods (see Takara and Stedinger, 1994):

SLSC =−−

δ min* *

2

1s sq q

(2)

PPCC =− −

− −=

==

�

��

( )( )

( ) ( )

y y r r

y y r r

i ii

N

i ii

N

i

N

1

2 211

1 2 (3)

Graphical methods are used, not for fitting probability distributions, but for verifying

the goodness-of-fit. Annual maximum series of rainfall have been used for flood control planning. Recently, discharge data have also been used to obtain quantile (T-year flood) estimates and compare them with values estimated by the conventional flood control planning procedure based on T-year storm and runoff analysis. The central government deals with 109 major rivers with return periods of 100, 150 or 200 years, while local governments use return periods of 30, 50 or 100 years for local rivers. The PDS or POT series has begun to be used (Tanaka and Takara, 2000, 2002). For low flows, an empirical method is used. For low flow situations a once in ten years or twice as twenty years frequency is used in practice. No consistent theoretical probability distribution is used in Japan. Probability distributions with both lower and upper bounds are also investigated (Takara and Tosa, 1999). Republic of Korea

Frequency analysis models in Korea are: Gamma (Pearson Type III), Lognormal, Log-Pearson Type III, Gumbel, etc. Methods of moments and PWM (probability weighted moments) are often used. Goodness-of-fit is tested by the Kolmogorov-Smirnov and chi-square tests, the relative root mean square error (RRMSE) and the PPCC (Kim et al., 1998). Flood control planning uses mostly annual maximum rainfall series, while partial duration runoff series are used sometimes. Return periods for major rivers are 100, 150 and 200 years. Local governments are using 30, 50, 80 years. Lao, P.D.R.

Soukhathammavong (1998), who proposed Project 4.5, indicates that the lognormal and Gumbel distributions are used in the central plain of Lao, P.D.R. The selection of distribution type is guided by the chi-square test. Low flow analysis is not applicable to this region because of very limited low flow observation. Malaysia

The Gumbel distribution is mostly used in frequency analysis for flood control planning in Malaysia. The parameter estimation uses the method of moments (MOM). Both rainfall and discharge records are used as annual maximum series. Urban areas use 100-year return period for design, while for rural (especially agricultural drainage areas) lower return periods are used, e.g. 50 or 25 years. The PPCC is used for goodness-of-fit



judgement. More information can be found on the Department of Irrigation and Drainage website (http://agrolink.moa.my/did/river/stormwater/index.html) where they have posted their storm water manual.

For low flows, the Type III extreme value (EV III) distribution is used. A hydrological procedure to estimate the magnitude and frequency of low flows in Peninsular Malaysia based on this distribution was developed in 1976. This was revised in 1985 and is still in use. The magnitudes of low flows are characterized by the duration of the low flow for e.g. 1, 4, 7, 14 & 30 days. The choice of duration is based on the permissible tolerance to water shortages or deficits decided by the planner. In this case a mean low flow of 7 days is the variable to be fitted to the EV III distribution.

Vietnam

According to Cao et al. (2001), statistical analysis is conducted for maximum rainfall, peak discharge and water level. Pearson type III distribution is used. If the data quality is bad or data length is too short, other methods are considered such as GRADEX, PMP/PMF and rainfall-runoff analysis to obtain design flood estimates. 5.3.2 Training and capacity building

Nothing is specified on training and capacity building for Working Group 4. 5.3.3 Contribution to scientific community

As outputs from this working group, a number of papers have been contributed to the scientific community. The papers have been presented in international journals and proceedings of international symposia and conferences and are listed in the references below. This section introduces some contributions presented by the working group members. Model fitting and Regionalization Study

Based on the annual maximum discharge data for 58 rivers in eight countries described in the three volumes of Catalogue of Rivers in Southeast Asia and the Pacific (UNESCO, 1995, 1997, 2000), Joesron Loebis (Project 4.2) obtained relationships for each country in the region between drainage area and average annual maximum discharge and between drainage area and standard deviation of annual maximum discharges (Joesron, 2002). Joesron (2001) also compared statistical and hydrological characteristics of floods in Indonesia and in New Zealand. He always uses the Gumbel distribution and frequency factor in his research (Joesron, 1999, 2000).

Zalina Mohd Daud and Amir Hashim Mohd Kassim (Project 4.4) conducted a detailed statistical analysis of the monthly and annual rainfall data in the state of Selangor, Malaysia. Thirty-four manually operated raingauges with archived data from 1903 to 1995 provided the input data for the analysis. Results of the analysis revealed the spatial and temporal pattern of the monthly and annual rainfall series in Selangor. Assessing various mathematical frequency distribution models, they determined the best distribution model for describing the extreme rainfall series in Selangor (Zalina et al., 1999a, 1999b).

Annual maximum series of fifteen-minute and sixty-minute durations from seventeen automatic rain gauges were used. The longest data set available was from 1971 to 1998 although missing data was also encountered. Eight probability distributions were used in the analysis namely the Gamma, Gumbel, GEV, GPA, GNO, PE3, LP3, and Wakeby. The procedure involved parameter estimation by the method of L-moment and goodness-of-fit test by the L-moment ratio diagram and some quantitative evaluation such as the



PPCC, the root mean square error (RMSE), the relative root mean square error (RRMSE) and the maximum absolute error (MAE). The results were further enhanced by investigating the extrapolative abilities of the distributions involved through bootstrap re-sampling of the quantiles.

Figure 5.1 Map of Peninsular Malaysia showing the location of the stations, the three best-fit distributions selected based on PPCC, RRMSE, RMSE and MAE values

and the boundaries of the homogeneous regions (Zalina et al., 2002)

The same procedure for probability distribution fitting was repeated using annual maximum data from seventeen other raingauges located throughout Peninsular Malaysia. The analysis has been completed for both Selangor and Peninsular Malaysia. The GEV has been concluded as the most suitable distribution to describe the annual maximum series. Further extension of the work has been the construction of intensity-duration-frequency (IDF) curves for the stations in Peninsular Malaysia based on the chosen distribution. Work on a regionalisation study has been carried out in the whole of Peninsular Malaysia using the same stations used previously in the distribution study (Zalina et al., 2002), as shown in Figure 5.1. The current work will be extended to cover East Malaysia (Sabah and Sarawak), which have not been included so far. By adding more stations to the investigation will further refine the regionalisation work and it is expected that an internet-based Rainfall Atlas for Malaysia will be developed.

Probable Maximum Precipitation and Flood

There are many research papers relating to the probable maximum precipitation (PMP) in all over the world (e.g., WMO, 1986; Pearce, 1993). Desa et al. (2000) analysed annual maximum 1-day rainfall data of 29-63 years for 33 stations in the region of Selangor, Malaysia to estimate PMP for 1-day duration by using the Hershfield method. Estimated PMPs at 33 locations in this region are within a range of 315-512 mm in 24 hours. A generalized 24-hour PMP is mapped over the Selangor region. Figure 5.2 shows



that more than 450 mm along the west coast, and around 375 mm at the north and south regions, while the PMP in the interior zone is 400 mm. They found out that average ratio of 24-hr PMP to 1-day PMP is approximately 2.0, which is also observed in for tropical region in India. Dang (1999) reported PMP/PMF approach in Vietnam (Project 4.6).

Figure 5.2 Generalized 24-hour PMP (mm) over Selangor, Malaysia, Calculated by the Hershfield method

Figure 5.3 Depth-duration relationships as a first-order estimation of PMP (Probable Maximum Precipitation) at a point based on the world and Japan records of

extraordinary storms [updated from Takara et al. (1996)].



Figure 5.4 Depth-Area-Duration relationships obtained by historical maximum radar rainfall in the Naka River basin

Figure 5.5 Comparison of the EV4 and Slade distributions in terms of goodness-of-fit and

the effect of the lower bound setting

Figure 5.3 shows the historical maximum precipitation in the world and in Japan for durations from one minute to one year. This Depth-Duration relationship gives statistical estimates of PMP at a point in the region considered. The working group coordinator prepared a web site for: depth-duration relationship of historical maximum precipitation in the world and Japan at http://fmd.dpri.kyoto-u.ac.jp/~flood/data/worldrec.html and http://fmd.dpri.kyoto-u.ac.jp/~flood/data/japanrec.html.

0

0.005

0.01

0.015

0.02

p. d

. f.

LN3EV4 (a=0)

0

0.005

0.01

0.015

0.02

p. d

. f.

LN3EV4 (a=30)

0

0.005

0.01

0.015

0.02

0 100 200 300

RAINFALL [mm]

p. d

. f.

LN3EV4 (a=54.5)

0

0.005

0.01

0.015

0.02

p. d

. f.

LN3Slade (a=0)

0

0.005

0.01

0.015

0.02

p. d

. f.

LN3Slade (a=30)

0

0.005

0.01

0.015

0.02

0 100 200 300

RAINFALL [mm]

p. d

. f.

LN3Slade (a=54.5)



The coordinator intended to produce similar tables and Depth-Duration relationships for countries in Southeast Asian and Pacific region, because this Depth-Duration relationship can provide a nationwide PMP estimate and contribute to comparative hydrological studies in the framework of the Asian Pacific FRIEND.

Using two radar rainfall observation systems with spatial resolution of 1.5 km and 34 raingauges in the Naka-gawa basin (3,270 km2) in Japan, Takara et al. (2000) conducted the depth-area-duration (DAD) analysis to derive PMP and then the corresponding probable maximum floods (PMF). They describe a procedure of estimating the PMP using radar raingauges and DAD analysis. Radar data obtained from two radars, which cover the Naka river basin in Japan, are calibrated with 45 ground raingauges. The radar data indicated the local extreme rainfall that ground raingauges could not detect. In obtaining the DA relationship with spatially distributed rainfall data, constant area and fixed rainfall methods were used and the difference between DAD equations given by the two methods was investigated. Figure 5.4 shows a DAD relationship obtained by a non-linear optimisation technique developed by Takara et al. (2000, 2001) to objectively calibrate parameters of the DAD equations. Consideration of Upper and Lower Bounds in Frequency Analysis

The above mentioned probable maximum hydrological extremes can be regarded as the upper bound of frequency analysis models. From this viewpoint, Takara and Tosa (1999) applied probability distributions with upper and lower bounds to hydrologic frequency analysis. Two distributions are applied to some data sets of extreme-value precipitation and river discharge: the Slade-type four-parameter log-normal distribution (Slade) and the extreme value distribution with lower and upper bounds (EV4 or EVLUB) proposed by Kanda (1981).

The Slade-type four-parameter LN distribution was proposed by Slade (1936):

��

�

�

��

�

�

��

�� −−−

−−−−=

2)}()(ln{

21exp

2))(()(

Y

Y

Y

xgaxxgaxagxf

σµ

πσ (3)

where σ Y , µY , a , and g are parameters which characterize the form of distribution. Iwai (1949) applied it to a 25-year discharge dataset at Kurihashi, the Tone River, Japan. Takara and Joesron (1996) also applied it to Japanese and Indonesian hydrological data.

Kanda’s EV4 distribution is:

��

�

�

��

�

�

��

��

−−−=

κ

ν )(exp)(

axxgxF ,

��

�

�

��

�

�

��

��

−−−

−−−= +

− κ

κκ

κ

ννκ

)(exp

)()()()( 1

1

axxg

axagxgxf (4)

where )(xF and )(xf are respectively the distribution function and the probability density function of a hydrological variable ix ; and ν , κ , a , and g are parameters which characterize the form of distribution. Particularly, a and g are the lower limit and the upper limit, respectively. Kanda (1981) empirically derived this distribution from three extreme-value distributions, and introduced it as a probability distribution model to express real phenomena such as earthquake motions and strong winds.

Their goodness of fit to the data sets is assessed in terms of the standard least-square criterion (SLSC). The goodness of fit assessment has demonstrated that the Slade distribution gives better SLSC values for datasets with sample skewness of less than 1.5 and that the EV4 distribution is better for datasets with larger sample skewness. The analysis using the bootstrap method indicates that these distributions with an upper bound give less variability in quantile estimates than the three-parameter lognormal distribution



with infinite upper bound (LN3). Figure 5.5 demonstrates the performance of these three distributions. The EV4 is more sensitive to the lower bound than the Slade distribution. This type of distributions would stimulate more physical consideration in “hydrologic” frequency analysis, because PMP (or PMF) should be estimated on the basis of meteorology and hydrology. Rakhecha and Krishnakumar (2002) also suggests the importance of estimation of PMP and DAD in a recent regional IHP meeting, demonstrating Indian case studies.

In this chapter, the WG4 Coordinator has not described what had been done in countries such as Australia (Pearce, 1993; Nandakumar, 1995; McConachy, 1995), New Zealand (Pearson and Davies, 1997), Thailand and the Philippines, which did not participate in the WG4 activities in Asian Pacific FRIEND Phase 1 (1997-2001). We may refer their achievements in literature already published or in the Phase 2 during the IHP-VI period (2002-2007). 5.4 Summary and recommendations

The working group has collected information about frequency analysis models and methods in several countries that proposed projects, and exchanged their experiences in the region through papers and presentations in the symposia and workshops during IHP-V (1997-2001). The main findings are: 1. The standard methods of the countries considered are different, depending on the

situation of the country. 2. Some countries have a standard method developed in the country, while others are

using traditional frequency analysis methods. 3. The Southeast Asia and Pacific region has had some difficulty maintaining continuous

hydrological observations because of the wars, and this resulted in relatively short records for frequency analysis.

4. Most countries use the annual maximum series (AMS); however, the partial duration series (PDS) or peaks-over-threshold (POT) series have also been used for short records or for discharge data.

5. Return periods for flood quantile estimation are different from country to country, depending on the hydrological regimes of the river basins.

6. Regionalization techniques have been investigated in some countries. 7. Frequency analysis for low flows is basically very primitive. No systematic approach

was found in the Region. 8. Application of re-sampling methods such as the jackknife and the bootstrap methods,

to frequency analysis is introduced to show the variability (or stability) of quantile estimates.

9. Probability distributions with both lower and upper bounds are also introduced, encouraging hydrological consideration of the probable maximum precipitation (PMP) and probable maximum flood (PMF). An extreme-value database, HEAP (Hydrological Extremes in Asian Pacific region),

has been established at Kyoto University in Japan. The HEAP database includes extreme discharge and rainfall data in the Catalogue of Rivers for Southeast Asia and the Pacific and some additional extreme-value data from some countries. The HEAP is anticipated to be a part of the Asian Pacific Water Archive and to form the basis for frequency analysis studies throughout the region.

As future directions, further studies on the following issues are recommended: • PMP (probable maximum precipitation) and PMF (probable maximum flood)



• Statistical relationships such as IDF (intensity-duration-frequency) and DAD (depth-area-duration)

• Linkage of frequency analysis methods with meteorological and hydrodynamic simulations

• New and improved techniques on estimating quantiles for ungauged sites 5.5 References Cao Dang Du, Trinh D. L., Dinh X. T., 2001. Evaluation of design flood on rivers of the

Central Viet Nam. Proc. International Symposium on Achievements of IHP-V in Hydrological Research, Hanoi, Vietnam, 19-22 November 2001, (Ed.) Tran Thuc, IHP-V Technical Document in Hydrology No. 8, UNESCO Jakarta Office, pp. 39-44.

Chen, Yuanfang, 1999. A New Weighted Function Moments Method to Estimate the Parameters of P-III Distribution with Historical Flood, Proceedings of International Symposium for flood and droughts, HOHAI UNIVERSITY PRESS, Nanjing, Oct. 1999, IHP-V Technical Document in Hydrology No. 4, UNESCO Jakarta Office.

Chen, Y., Hou, Y., van Gelder, P. and Sha, Z., 2002. The Extremes of The Extremes: Extraordinary Floods, (Eds.) A. Snorasson, H.P. Finnsdottir and M. Moss, IAHS Pub. No. 271, pp. 263-269.

Dang Lan Huong, 1999. Estimation of Extreme Flood by PMP/PMF Method. Asian Pacific FRIEND and GAME Joint Workshop on ENSO, Floods and Droughts in the 1990’s in Southeast Asia and the Pacific. Hanoi, Vietnam. 23 – 26 March 1999.

Desa M., M.N. and Z. Daud, 1998. On Spatial and Temporal Properties of Rainfall in Selangor, Malaysia, Proceedings of International Symposium on Hydrology, Water Resources and Environmental Development and Management in Southeast Asia and the Pacific, organized by IHP-RSC, Korean National Committee for the IHP, Yeungnam University, Taegu, Republic of Korea, Nov. 10 – 13, 1998, pp. 347-356.

Desa M., M.N., A.B. Noriah and P.R. Rakhecha, 2000. Probable Maximum Precipitation for 24 hrs Duration Over the Southeast Asian Monsoon Region---Selangor, Malaysia, Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, 21-24 November 2000, (Ed.) M. Paul Mosley, pp. 80-95.

Joesron Loebis, 1999. Frequency analysis on water level decrease of Lake Toba, Proc. International Symposium on Floods and Droughts, Nanjing, China, 18-21 October 1999, IHP-V Technical Documents in Hydrology No. 7, UNESCO Jakarta Office, 1999, pp. 445-453.

Joesron Loebis, 2000. Frequency analysis of extreme climate events for flood design in Indonesia, Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, 21-24 November 2000, (Ed.) M. Paul Mosley, pp. 7-15.

Joesron Loebis, 2001. Comparative hydrological study on design flood between river in Indonesia and New Zealand, Proc. International Symposium on Achievements of IHP-V in Hydrological Research, Hanoi, Vietnam, 19-22 November 2001, (Ed.) Tran Thuc, IHP-V Technical Document in Hydrology No. 8, UNESCO Jakarta Office, pp. 127-133.

Joesron Loebis, 2002. Frequency analysis models for long hydrological time series in Southeast Asia and the Pacific region. FRIEND 2002---Regional Hydrology: Bridging the Gap between Research and Practice, IAHS Publication no. 274, (Eds.) Henny A.J. van Lanen and Siegfried Demuth, 2002, pp. 213-219.



Kanda, J., 1981. A New Extreme Value Distribution With Lower and Upper Limits for Earthquake Motions and Wind Speeds，Theoretical and Applied Mechanics，Vol. 31, University of Tokyo Press, pp. 351-354.

Kim, K.-D., Heo, J.-H. and Cho, W., 1998. Flood frequency Analysis Based on Parametric and Smoothing Methods, Proceedings of International Symposium on Hydrology, Water Resources and Environmental Development and Management in Southeast Asia and the Pacific, organized by IHP-RSC, Korean National Committee for the IHP and Yeungnam University, Taegu, Republic of Korea, Nov. 10 – 13, 1998, pp. 109-120.

McConachy, F., 1995. Estimation of Extreme Rainfalls for Victoria: Application of Schaefer’s method. Cooperative Research Centre for Catchment Hydrology, Working Document 95/6, Australia, June 1995, 42 pp.

Nandakumar, N., 1995. Estimation of Extreme Rainfalls for Victoria: Application of the Forge method. Cooperative Research Centre for Catchment Hydrology, Working Document 95/7, Australia, June 1995, 39 pp.

Pearce, H.J., 1993. A history of PMP application for the Warragamba Dam catchment. Australian Civil Engineering Transactions, Vol. CE35, No. 2, pp. 131-138.

Pearson, C. and Davies, T., 1997. Stochastic methods. In Floods and Droughts: the New Zealand Experience, (Eds.) M. Paul Mosley and Charles P. Pearson, New Zealand Hydrological Society, Chapter 5, pp. 65-87.

Rakhecha, P.R. and Krishnakumar, G., 2002. Determination of design storms in India. International Symposium on Comparative Regional Hydrology and Mission for IHP Phase VI of UNESCO, Kuala Lumpur, Malaysia, 14-16 October 2002, (Eds.) Desa, M. M.N., Shahar M., S. and Sarvamudhty, S., IHP-VI Technical Documents in hydrology No. 1, UNESCO Jakarta Office, 2002, pp. 86-95.

Slade, J. J., 1936. An Asymmetric Probability Function, Trans. ASCE, Vol. 62, pp. 35-61 with Discussion (pp. 62-104).

Soukhathammavong, K., 1998. Flood and low flow in central plain of Lao, P.D.R., Proc. of 1st Asian Pacific FRIEND Workshop: Data archive and scientific methods for comparative hydrology and water resources, Kuala Lumpur, Malaysia, 20-23 March 1998, (Eds.) M. Desa, M.N., Ghazali, Z. and Sinnasamy, S., IHP-V Technical Documents in Hydrology, No. 1, UNESCO Jakarta Office, 1999, pp. 109-122.

Takara, K., Hashino, T. and Nakao, T., 2000. PMF estimation based on a distributed hydrological model and DAD analysis using radar raingage data. Proc. 4th International Conference Hydroinformatics 2000. Iowa Institute of Hydraulic Research, University of Iowa, USA, CD-ROM, 8 pp.

Takara, K., Hashino, T. and Nakao, T., 2001. Application of radar raingage and nonlinear optimisation to DAD analysis. Journal of hydraulic, Coastal and Environmental Engineering. Japan Society of Civil Engineers, No. 691/II-57, pp. 1-11 (in Japanese).

Takara, K. and Joesron Loebis, 1996. Frequency analysis introducing probable maximum hydrologic events ---Preliminary studies in Japan and in Indonesia---. Proc. of International Symp. on Comparative Research on Hydrology and Water Resources in Southeast Asia and the Pacific, Yogyakarta, Indonesia, November 18-22, 1996, Indonesian National Committee for International Hydrological Programme, pp. 67-76.

Takara, K., Takasao, T. and Tomosugi, K. (1996), Possibility and necessity of paradigm shift in hydrologic frequency analysis. Proc. of International Conference on Water Resources & Environment Research: Towards the 21st Century, organized by Water Resources Research Center, Kyoto University, held at Heian Kaikan, Kyoto, Japan, October 29-31, 1996, Vol. I, pp. 435-442.



Takara, K. and Nakayama, D., 2000. HEAP: hydrological extreme-value database for Asian Pacific FRIEND, Proc. of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, 21-24 November 2000, IHP-V Technical Documents in Hydrology No. 7, UNESCO Jakarta Office, 2000, pp. 255-261.

Takara, K. and J. R. Stedinger, 1994. Recent Japanese Contributions to Frequency Analysis and Quantile Lower Bound Estimators, Stochastic and Statistical Methods in Hydrology and Environmental Engineering, Vol. 1, pp. 217-234.

Takara, K. and Tosa, K., 1999. Storm and Flood Frequency Analysis Using PMP/PMF Estimates, Proc. International Symposium on Floods and Droughts, Nanjing, China, 18-21 October 1999, IHP-V Technical Documents in Hydrology No. 7, UNESCO Jakarta Office, 1999, pp. 7-17.

Tanaka, S. and Takara, K., 2000. AMS or PDS? Some experience in frequency analysis of floods in Japan, Proc.4th International Conference Hydroinformatics 2000. Iowa Institute of Hydraulic Research, University of Iowa, USA, CD-ROM., 8 pp.

Tanaka, S. and Takara, K., 2002. A study on threshold selection in POT analysis of extreme floods, The Extremes of The Extremes: Extraordinary Floods, IAHS Pub. No. 271, (Eds.) A. Snorasson, H.P. Finnsdottir and M. Moss, pp. 299-304.

UNESCO, 1995. Catalogue of Rivers for Southeast Asia and the Pacific, Vol.1, (Eds.) K. Takeuchi, A.W. Jayawardena and Y. Takahashi, The UNESCO-IHP Regional Steering Committee for Southeast Asia and the Pacific, October 1995, 291 pp.

UNESCO, 1997. Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 2, (Eds.) A.W. Jayawardena , K. Takeuchi and B. Machbub, The UNESCO-IHP Regional Steering Committee for Southeast Asia and the Pacific, December 1997, 285 pp.

UNESCO, 2000. Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 3, (Eds.) Hidayat Pawitan, A.W. Jayawardena , K. Takeuchi and Soontak Lee, The UNESCO-IHP Regional Steering Committee for Southeast Asia and the Pacific, May 2000, 268 pp. and CD-ROM

UNESCO, 2002. Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 4, (Eds.) R. Ibbitt, K. Takara, Mohd. Nor bin Mohd Desa and Hidayat Pawitan, The UNESCO-IHP Regional Steering Committee for Southeast Asia and the Pacific, March 2002, 338 pp. and CD-ROM.

Wang, Guoan, 1999. Principles and Methods of PMP/PMF Calculations, Yellow River Water Resources Publication, 612 pp.

WMO, 1986. Manual for Estimation of Probable Maximum Precipitation. Operational Hydrology Report No. 1, World Meteorological Organization, No. 332 (Second Ed.), .

Zalina Mohd Daud, Amir Hashim Mohd Kassim, Mohd Nor Mohd Desa and Van-Than-Van Nguyen, 2002. Statistical analysis of at-site extreme rainfall processes in Peninsular Malaysia. FRIEND 2002 ---Regional Hydrology: Bridging the Gap between Research and Practice, (ed.) Henny A.J. van Lanen and Siegfried Demuth, IAHS Publication no. 274, 2002, pp. 61-68.

Zalina Mohd. Daud, V.T.V. Nguyen, Amir Hashim Mohd Kassim and M. N. M. Desa, 1999a. Statistical Modelling of Extreme Rainfall Processes. Proc. Asian Pacific FRIEND and GAME Joint Workshop on ENSO, Floods and Droughts in the 1990’s in Southeast Asia and the Pacific. Hanoi, Vietnam. 23 – 26 March 1999, pp. III-1-III-10.

Zalina Mohd Daud, V.T.V. Nguyen, Mohd Nor Mohd Desa and Amir Hashim Mohd Kassim, 1999b. Selection of Best Candidate Distribution and Robust Quantile Estimates for Extreme Rainfall Process, Proc. International Symposium on Floods and Droughts, Nanjing, China, 18-21 October 1999, IHP-V Technical Documents in Hydrology No. 7, UNESCO Jakarta Office, 1999, pp. 18-26.

Chapter 6: Working Group 5: Human Adjustment Models


6. WORKING GROUP 5: HUMAN ADJUSTMENT MODELS Following determined efforts by Working Group 5 as to how it could meet its

objectives, it was forced to conclude that lack of suitable data would prevent it meeting its stated objective. Should an objective of this nature be re-justified in IHP-VI, primary consideration needs to be given to defining what type of data need to be collected, and what sort of techniques need to be implemented for their collection. It was decided at the 10th RSC meeting that it would be useful for any future work on this topic and also for the second phase of Asian Pacific FRIEND, to have a list of the relative importance of various hydrological issues affected by human activities. Accordingly, the UNESCO Jakarta Office drew up following questionnaire for circulation to participating countries. Indicate for each objective which one reason you think is most important to your country. Obj1 – Why do we want “to manage risk in the water cycle”? Do we want to do it to: 1). Reduce loss of life caused by floods? 2). Reduce loss of agricultural production? 3). Reduce loss of industrial production? 4). Minimize the effects of pollutants on the in stream habitat? 5). Minimize the effect of pollutants on fisheries? 6). Minimize disruption to navigation? 7). Maximize use of the water resource? 8). Minimize the harmful effect of environmental and natural disasters on public health? 9). Ensure reliable water supplies for towns and cities? 10). Reduce contribution of sediment to streams? 11). Any other reason? Obj2 – Why do we want “to develop better understanding of hydrological variability and similarity across time and space”? Is it because we want to: 1). Reduce the cost of data collection? 2). Make more reliable decisions about water resource management? 3). Estimate acceptable water withdrawals on any reach of a stream? 4). Improve estimates of the time taken for floods to travel downstream? 5). Minimize the impacts of land development and use on rivers? 6). Provide comprehensive river information for integrated basin management? 7). Better manage ungauged basins? 8). Improve physical understanding of hydrological processes for sustainable water

resource management? 9). Any other reasons? Obj3 – Why do we want “to develop integrated catchment management”? Is it so that: 1). The water resources are used fairly between competing users? 2). The risk of conflict amongst the exploiters of the water resource is minimized? 3). Basin productivity is maximized? 4). The water resources of a basin are used in a sustainable way? 5). Minimum flows needed to sustain in stream habitat can be determined? 6). The ecology of river basin is better preserved?

Chapter 6: Working Group 5: Human Adjustment Models


7). The decision making process regarding sustainable use of water resource can be improved?

8). A logical institutional framework for water management can be established? 9). A logical water policy framework can be established? 10). Any other reason? Obj4 – Why do you want “to continue developing the mutual exchange and sharing of data through the establishment of regional hydrological databases and the sharing of knowledge and techniques between countries at a regional level”? 1). Sharing of data maximizes the benefits of the collection of the data. 2). Regional exchanges of data reduces the risk of international conflict by enabling

neighbouring countries to know how each other utilize the available water resources of a river.

3). It helps my research. 4). My students can address water problems using real data. 5). Increased spatial and temporal data coverage help improve the reliability of water

resources assessment. 6). Exposing data to wide scrutiny improves its quality and hence the reliability of

decisions based on that data. 7. It would improve understanding of physical phenomena through comparative studies

of these phenomena under different climatological and physiographic conditions 8). Any other reasons? Obj5 – Why do you want “to share the research outcomes through the dissemination of international and regional co-operation”? 1). It enhances my reputation for publishing good work and is more likely to draw in

research expertise from outside the region. 2). It maximises the benefits of research carried out by a scare human resource. 3). It leads to quicker solutions to river-related issues. 4). Others may improve on my work thereby advancing the state of knowledge about

research on rivers. 5). It may improve the productivity of the river basin through better integration of the

management of the water resource. 6). It would provide opportunities for developing joint research projects dealing with

complex water problems ( or issues ) of common interest 7). Any other reason?

Chapter 7: Summary and recommendations


7. SUMMARY AND RECOMMENDATIONS

7.1 Key achievements of Asia Pacific FRIEND Since the science plan of the Asian Pacific FRIEND was published in 1999, more than

200 researchers and practitioners in the Region have participated in projects. Although programme implementation is still at its early stage, there have been some notable achievements. The main progress in hydrological research resulting from Asian Pacific FRIEND may be summarized as follows:

1. The Asian Pacific Water Archive, which includes river flow, hydrometeorological and

other related water resources information for 94 rivers from 13 member countries, has been successfully established and operates at the Regional Humid Tropics Hydrology and Water Resources Centre (http://htc.moa.my/apfriend/wa). Two country nodes have also been established in Japan and Australia.

2. Rainfall-runoff models: Several rainfall-runoff models, being capable of application to small basins dominated by rainfall-runoff processes, and large catchments dominated by complex channel and storage processes, have been developed and calibrated. As one of those models, the physically-based distributed hydrological model, BTOPMC, developed at Yamanashi University, was successfully tested and validated from small river basins to large basins such as the Fuji River in Japan, the Mekong River, as well as the Yellow River in China.

3. Statistical models: Long-term data in the region has been analysed and new statistical and stochastic approaches have been developed.

4. Frequency analysis models: A range of frequency analysis models has been tested with extreme data sets from across the region and the applicability of these models has been evaluated. The results will provide useful information for the frequency analysis studies and water resources development in the Southeast Asia and Pacific region.

5. Human adjustment models: Human adjustment structures and simulation of these structures aimed at decreasing the damages due to both flood and drought, including social, economic, and cultural elements, have been initially studied. The natural and social factors contributing to the increase in flood and drought losses in the region are being identified and investigated.

Besides these contributions to hydrological science, other achievements include the

publication of four volumes of the Catalogue of Rivers for Southeast Asia and the Pacific, covering 94 river basins from 13 member countries, the organizing of many technical workshops, symposia, and conferences, and the publications of those workshop/symposia proceedings.

The Asian Pacific FRIEND has established links with other regional and international

research programmes. Examples include the link between Asian Pacific FRIEND and GEWEX/GAME in Japan, China, Thailand, Indonesia, etc. These links will strengthen the continuing research program of Asian Pacific FRIEND. 7.2 Applications and future initiatives in IHP VI

In the second stage of implementation, the major challenge will be to find the necessary financial support for collaborative projects undertaken by the working groups. The Technical Sub-Committee (TSC) for Asian Pacific FRIEND, working group coordinators, and the Regional Steering Committee (RSC) will make great efforts in

Chapter 7: Summary and Recommendations


seeking financial support for participants. In this respect, stronger collaboration with a wide range of national, international, regional, and global organizations and programmes is strongly recommended for the second phase of the Asian Pacific FRIEND.

Possible collaboration with the Asian Development Bank (ADB), Mekong River

Commission, World Water Assessment Program (WWAP), Hydrology for Environment, Life and Policy (HELP), and WMO Hydrology and Water Resources Programs (HWRP) is also very significant and should be regarded as one direction for efforts in the future.

Due to the success of the FRIEND project in its first phase as well as the

interdisciplinary feature of its research, FRIEND has been designated as the “cross-cutting” theme in the IHP VI from 2002 to 2007. This provides an opportunity for FRIEND to contribute to the majority of the key themes of IHP VI and to strengthen links with other initiatives of the IHP VI. The Asian Pacific FRIEND initiatives in IHP-VI may include:

1. Increasing stakeholder participation in planning FRIEND projects and making greater

efforts to transfer research outputs into practical and directly usable procedures, 2. Improving knowledge of the spatial and temporal distribution of precipitation and

streamflow, 3. Integrating research on hydrology and water resources, and 4. Investigating the impact of climate and land-use changes on hydrological processes

and water resources. IHP-VI will give a higher priority to transferring research output to the user

community. This is also a continuing challenge for the Asian Pacific FRIEND. 7.3 Other issues

The Asian Pacific FRIEND project wishes to share its experience and findings with other regional FRIEND projects, in particular its experience in the development of the database as a network of national nodes and the publication of the Catalogues of Rivers may be helpful for the development of new regional FRIEND projects.

Chapter 8: Conclusions


8. CONCLUSIONS Over the past five years of the first phase for the Asian Pacific FRIEND, significant

progress in initiating research and organising training for capacity building through the activities of the five working groups has been made. Member countries and participants have shown great enthusiasm and interest to participate in and host various activities in the Region.

The Asian Pacific FRIEND has had considerable success in fostering Regional

collaboration and data sharing in hydrology and water resources, particularly through network communications among participants, establishing regional databases, joint research, capacity building and publications. The network has provided the forum for the exchange of ideas, models, data, and related research. As represented in Annex 4, the Asian Pacific FRIEND project disseminates its research output through technical meetings, international conferences, seminars, workshops, International FRIEND reports and peer-reviewed scientific papers in journals. In Annex 4, although not including all, a sample of the publications produced by Asian Pacific FRIEND participants during the first phase of the project are listed.

Since the Asian Pacific Science Plan was published, more than 200 researchers and

practitioners in the region have contributed and their activities coordinated. Although programme implementation is still at an early stage, there have been notable achievements. These include the publication of four volumes of the Catalogue of Rivers for Southeast Asia and the Pacific, covering 94 rivers from 13 member countries in the region, the establishment of the Asian Pacific Water Archive, the organization of annual Asian Pacific FRIEND symposia and the publication of a series of symposium and workshop proceedings. Asian Pacific FRIEND has been successful in stimulating collaboration between the countries in the region and collaboration with other related organizations and programmes such as GEWEX/GAME is being established. Asian Pacific FRIEND is a success for UNESCO/IHP, for the participating countries in the Southeast Asia and Pacific region and for the members and organizations involved.

References


REFERENCES Gustard, A., and Cole, G. A. (2002). FRIEND – A global perspective 1998-2002. Centre

for Ecology and Hydrology – Wallingford UK. UNESCO (1995): Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 1, (Eds.)

Takeuchi, K., Jayawardena, A.W. and Takahashi, Y., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 291 pp.

UNESCO (1997): Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 2, (Eds.) Jayawardena, A.W., Takeuchi, K. and Machbub, B., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 285 pp.

UNESCO (2000): Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 3, (Eds.) Pawitan, H., Jayawardena, A.W., Takeuchi, K. and Lee, S., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 268 pp. and CD-ROM.

UNESCO (2002): Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 4, (Eds.) Ibbitt, R., Takara, K., Mohd. Nor bin Mohd. Desa and Pawitan, H., The UNESCO-IHP Regional Steering Committee (RSC) for Southeast Asia and the Pacific, 338 pp. and CD-ROM.

UNESCO Jakarta Office (1999): Proceedings of the 1st Asian Pacific FRIEND Workshop: Data archive and scientific methods for comparative hydrology and water resources, Kuala Lumpur, Malaysia, 20-23 March 1998, IHP-V, Technical Documents in Hydrology, No. 1.

Annexes


ANNEX 1. ABBREVIATIONS AP FRIEND Asian Pacific FRIEND FRIEND Flow Regimes from International Experimental and Network Data

Sets DAD Depth area duration EV III Type III extreme value GEV Generalized extreme-value distribution GM Graphical method GNO Generalized normal distribution GPA Generalized Pareto distribution IDF Intensity-duration-frequency LM L-moments LP-III or LP3 log-Pearson Type III distribution LS least-squares method MAE Maximum absolute error MLE maximum likelihood estimation method MOM method of moments P-III Pearson Type III distribution (Gamma distribution) PE3 Pearson Type III distribution PPCC Probability plot correlation coefficient PMF probable maximum flood PMP probable maximum precipitation POT Peaks over threshold PWM Probability weighted moments RMSE Root mean square error RRMSE Relative RMSE RSC Regional Steering Committee SLSC Standard least square criterion TSC Technical Sub-Committee ANNEX 2. COUNTRIES PARTICIPATING AND COORDINATORS Presently nearly 200 researchers from thirteen countries including Australia, Cambodia, China, Indonesia, Japan, Rep. of Korea, Lao, Malaysia, New Zealand, Papua New Guinea, The Philippines, Thailand, and Vietnam participate in the five working groups. Coordinators for five working groups are as follows: Working Group 1: Dr. Mohd. Nor bin Moh. Desa Department of Irrigation and Drainage Malaysia Km 7, Jalan Ampang Ampang, Kuala Lumpur Malaysia Tel: (603) 4532448 Fax: (603) 4561894 E-mail: [email protected]

Annexes


Mr. Ross James Bureau of Meteorology P.O. Box 1289K Melbourne 3001

Australia Tel: +61(3)9669-4605 Fax: +61(3)9669-4725 E-mail: [email protected] Working Group 2: Prof. Kuniyoshi Takeuchi Institute of Material and Environmental Technology Graduate School of Engineering Yamanashi University Takeda 4-3-11, Kofu 400-8511 Japan Tel: +81(55)220-8603 Fax: +81(55)253-4915 E-mail: [email protected] Working Group 3: Prof. Soontak Lee

Yeungnam University 487-1, Daemyung-9 Dong, Namku, Taegu 705-039 Rep. of Korea Tel: +82(53)810-2412

Fax: +82(53)813-4032 E-mail: [email protected]

Working Group 4: Prof. Kaoru Takara

Flood Disaster Research Section DPRI, Kyoto University Gokasho, Uji 611-0011 Japan Tel: +81(774)38-4125 Fax: +81(774)38-4130 E-mail: [email protected]

Working Group 5: Kasem Chunkao (Thailand) [email protected] (resigned)

Annexes


ANNEX 3. CATALOGUE OF RIVERS: RIVER BASINS INCLUDED

River No. Country No. Country River River Name 1 1 Australia 1-Vol.1 Burdekin River 2 2-Vol.1 Pioneer River 3 3-Vol.2 Todd River 4 4-Vol.2 East Finniss River 5 5-Vol.3 Torrens River 6 6-Vol.3 Scott Creek 7 2 Cambodia 1- Vol.1 Prek Thnot 8 2- Vol.2 Stung Chinit 9 3 China 1- Vol.1 Bei-jiang 10 2- Vol.1 Jin-jiang 11 3- Vol.1 Jiyun-he 12 4- Vol.2 Gan-jiang 13 5- Vol.2 Taizi-he 14 6- Vol.2 Ou-jiang 15 7- Vol.3 Bailong-jiang 16 8- Vol.3 You-jiang 17 9- Vol.3 Huang-he 18 10- Vol.4 Fen-he 19 11- Vol.4 Hongshui-he 20 12- Vol.4 Jialing-jiang 21 13- Vol.4 Luan-he 22 4 Indonesia 1- Vol.1 Citarum 23 2- Vol.1 Bengawan Solo 24 3- Vol.1 Kali Brantas 25 4- Vol.1 Sungai Asahan 26 5- Vol.2 Citanduy 27 6- Vol.2 Kali-Progo 28 7- Vol.3 Cimanuk 29 8- Vol.3 Kali Serayu 30 9- Vol.4 Kali Tuntang 31 10- Vol.4 Jeneberang River 32 5 Japan 1- Vol.1 Yoshino-gawa 33 2- Vol.1 Ara-kawa 34 3- Vol.1 Mogami-gawa 35 4- Vol.2 Chikugo-gawa 36 5- Vol.2 Fuji-kawa 37 6- Vol.2 Ishikari-gawa 38 7- Vol.3 Shimanto-gawa 39 8- Vol.3 Shonai-gawa 40 9- Vol.3 Watarase-gawa 41 10- Vol.4 Shinano-gawa 42 11- Vol.4 Tone-gawa 43 12- Vol.4 Yodo-gawa 44 6 Korea (Republic of) 1- Vol.1 Pyungchang-gang 45 2- Vol.1 Geumho-gang 46 3- Vol.1 Miho-chun

Annexes


River No. Country No. Country River River Name 47 4- Vol.2 Soyang-gang 48 5- Vol.2 Nam-gang 49 6- Vol.2 Gap-chun 50 7- Vol.3 Nam Han-gang 51 8- Vol.3 Huang-gang 52 9- Vol.3 Geum-gang 53 10- Vol.4 Seomjin-gang 54 11- Vol.4 Milyang-gang 55 12- Vol.4 Sapkyo-chun 56 7 Lao PDR 1- Vol.2 Nam Khane 57 2- Vol.2 Nam Ngum 58 3- Vol.2 Sedone 59 4- Vol.3 Nam Theun/Cading 60 5- Vol.3 Nam Sebangfay 61 6- Vol.3 Nam Sebanghieng 62 7- Vol.4 Nam Ou 63 8- Vol.4 Nam Suang 64 9- Vol.4 Sekong 65 8 Malaysia 1- Vol.1 Rajang Batang 66 2- Vol.2 Sungai Johor 67 3- Vol.4 Kelantan River 68 4- Vol.4 Chalok River 69 9 New Zealand 1- Vol.1 Buller River 70 2- Vol.2 Motu River 71 3- Vol.2 Hutt River 72 4- Vol.3 Taieri River 73 5- Vol.4 Mahurangi River 74 10 Papua New Guinea 1- Vol.2 Ramu Wara 75 2- Vol.3 Purari Wara 76 3- Vol.4 Sepik Wara 77 11 Philippines 1- Vol.1 Ilog Magat 78 2- Vol.1 Ilog Pampanga 79 3- Vol.2 Ilog Itaas ng Agno 80 12 Thailand 1- Vol.1 Mae Nam Ping 81 2- Vol.1 Mae Nam Mae Klong82 3- Vol.2 Mae Nam Nan 83 4- Vol.3 Mae Nam Yom 84 5- Vol.3 Mae Nam Wang 85 6- Vol.4 Prachinburi River 86 7- Vol.4 Bang Pakong River 87 8- Vol.4 Tonle Sap River 88 9- Vol.4 East Coast Gulf River89 13 Vietnam 1- Vol.1 Song Ky Cung 90 2- Vol.1 Song Thu Bon 91 3- Vol.1 Song Ba 92 4- Vol.1 Song Srepok 93 5- Vol.4 Cau River 94 6- Vol.4 Tra Khuc River

Annexes


ANNEX 4. EXAMPLES OF WORKING GROUP PUBLICATIONS Books Ibbitt, R., Takara, K., Mohd. Desa, M. N. b., and Pawitan, H. (2002). Catalogue of Rivers for Southeast Asia and the Pacific, Vol. 4, pp.338. Pawitan, H., Jayawardena, K., Takeuchi, K., and Lee, S. (2000). Catalogue of rivers for Southeast Asia and the Pacific, Vol. 3, pp.268. Jayawardena, A. W., Takeuchi, K., and Machbub, B. (1997). Catalogue of rivers for Southeast Asia and the Pacific, Vol. 2, pp.285. Takeuchi, K, Jayawardena, A. W., and Takahasi, Y. (1995). Catalogue of rivers for southeast Asia and the Pacific, Vol. 1, pp.291. Proceedings Desa, M. M. N., Ghazali, Z., and Sinnasamy, S. (1998). Proceedings of the 1st Asian

Pacific FRIEND Workshop: Data Archive and Scientific Methods for Comparative Hydrology and Water Resources. Kuala Lumpur, Malaysia, pp. 242.

Desa, M. M. N., Shahar, M. S., and Sarvamudthy (2002). Proceedings of the Symposium on Comparative Regional Hydrology and Mission for IHP Phase VI of UNESCO. Kuala Lumpur, Malaysia, pp.238.

Herath, S., and Dutta, D. (2000). Mekong basin studies, Proceedings of the AP FRIEND Workshop, pp.164.

Liu, H., Zhu, X. Y., Xing, Y. G., and Ye, T. (1999). Proceedins of the International Symposium on Floods and Droughts. Nanjing, P. R. China. pp.817.

Mosley, M. P. (2000). Proceedings of the Fresh Perspective on Hydrology and Water resources in Southeast Asia and the Pacific. Christchurch, New Zealand. pp.315.

Pho, N. V. (1999). Proceedings of the 2nd Asian Pacific FRIEND and GAME Joint Workshop on

Thuc, T. (2001). Proceedings of the International Symposium on Achievements of IHP-V in Hydrological Research. Ha Noi, Viet Nam. pp.432.

UNESCO Jakarta Office (1999). ENSO, Floods and Droughts in the 1990’s in Southeast Asia and the Pacific. Hanoi, Vietnam, pp.330.

Papers (Proceedings and journal papers produced in relation to the WG activities) Adams, K. N. (1999). Streamflow response to vegetation change in large catchments:

investigations using computer modelling. Proc. NZ Hydrological Society Annual Symposium, Napier, New Zealand.

Ao, T. Q., Ishidaira, H., and Takeuchi, K. (1999). Study of distributed runoff simulation model based on block type TOPMODEL and Muskingum-Cunge method. Ann. J. Hydraul. Engrg. (in Japanese), 43, 7-12.

Copeland, J.H.; Henderson, R.D.; Ibbitt, R.P.; Marks, C.; Wratt, D.S. (1998). “Linking atmospheric and hydrological models”. Presented at joint conference of the Meteorological Society of New Zealand and the Hydrological Society of New Zealand, Dunedin, November 1998.

Henderson, R.D.; Ibbitt, R.P.; Duncan, M.J. (1999). Cropp River: data to test concepts of channel network and river basin heterogeneity – data note. Journal of Hydrology (NZ) 38: 331–339.

Henderson, R.C., Ibbitt, R.P., and McKerchar, A.I. (2000) Reliability of low flow estimation by linear regression in small ungauged basins, paper presented to the Fresh

Annexes


Perspectives Symposium, a joint UNESCO IHP meeting with the Meteorological Society of New Zealand, the New Zealand Hydrological Society and the New Zealand Limnological Society, Christchurch, New Zealand, November 2000.

Henderson, R.D.; Copeland, J.H.; Ibbitt, R.P.; Wratt, D.S. (1999). Flood forecasting for the new millennium. Water and Atmosphere 7(4): 22 - 25.

Ibbitt, R.P.; and Pearson, C.P., (1998). Overview of New Zealand Hydrological Network, Database, and Science Projects, paper presented to the 1st Asian/Pacific FRIEND Workshop on Data Archive and Scientific Methods for Comparative Hydrology and Water Resources, held at the Regional Humid Tropics Hydrology and Water Resources Centre for Southeast Asia and the Pacific, Kuala Lumpur, Malaysia, 20-23 March 1998.

Ibbitt, R.P. (1998). Building a hydrological archive of Vietnamese data, Proceedings of the Intl. Symp. on Hydrology and Water Resources for Research and Development in Southeast Asia and the Pacific held at Nong Khai, Thailand, 16-19 December, 1998, published by the National Research Council of Thailand, pp 269-281.

Ibbitt, R.P.; Henderson, R.D.; Copeland, J.; Wratt, D.S. (1999). “Rainfall-runoff modelling forecasts based on successive meso-scale weather model forecasts: performance results along a 500-km range of mountains”. Presented at International Symposium on Floods and Droughts, Nanjing, China, October 1999, and published in the proceedings: IHP-V Technical Documents in Hydrology (UNESCO Jakarta Office) no .4, pp 431–444.

Ibbitt, R.P. (1999). Results from linked precipitation/riverflow modelling system, for the Ashburton catchment from the SALPEX’96 period. Presented to Canterbury Regional Council staff, Christchurch, February 1999.

Ibbitt, R.P.; Henderson, R.D.; Copeland, J.; Wratt, D.S. (1999). “Flood forecasting using mesoscale rainfall forecasts”. Presented at Meteorological Society of New Zealand and the New Zealand Geophysical Society Inc. Joint Conference on Natural Hazards and Climate Change, Victoria University of Wellington, September 1999.

Ibbitt, R.P.; Henderson, R.D.; Copeland, J.H.; Wratt, D.S. (1999). The potential of meso-scale weather model rain forecasts for enhancing flood warnings. Presented at the New Zealand Hydrological Society Symposium, Napier, November 1999.

Ibbitt, R P.; Henderson, R.D.; Copeland, J.H.; Wratt, D.S. (1999). Flood forecasting using meso-scale rainfall forecasts. Presented to the International Workshop on Flood Forecasting for Tropical Regions, Kuala Lumpur, Malaysia, June 1999.

Ibbitt, R.P., 2000, Modelling the Nam Gnouang Catchment, Lao PDR, paper presented to the Mekong Simulation Study Workshop, Asian Institute of Technology, Bangkok, Thailand, 24-25 January 2000.

Ibbitt, R.P.; R Al-Soufi, 2000, Assessing trans-border data for use in synthesising flow data in Cambodian Rivers, paper accepted for presentation to the Workshop on Hydrologic and Environmental Modelling in the Mekong Basin, Phnom Penh, Cambodia, 11-12 September 2000.

Ibbitt, R.P.; Henderson, R.D.; Copeland, J.; Wratt, D.S. (2000) Simulating mountain runoff with meso-scale weather model rainfall estimates: a New Zealand experience. Journal of Hydrology 239(1-4), pp 19-32.

Ibbitt, R. P., Henderson, R. D., Woods, R.A., Copeland J.C., and Lew D.: Operational use of a combined meso-scale precipitation model and rainfall-to runoff model for flood forecasting, paper presented to the Fresh Perspectives Symposium, a joint UNESCO IHP meeting with the Meteorological Society of New Zealand, the New Zealand Hydrological Society and the New Zealand Limnological Society, Christchurch, New Zealand, November 2000.

Annexes


Ibbitt, R.P.; and Henderson, R.D.,(1998). Filling in Missing Data in Flow Records, in Proceedings of the International Symp. on Hydrology, Water Resources and Environmental Development and Management in Southeast Asia and the Pacific, published by The Organizing Committee, Dept of Civil Eng., Yeungnam University, 214-1 Daedong, Kyongsan 712-749, Republic of Korea.

Shimada, J., Shimmi, O., Tanaka, T., Nakai, N., and Itadera, K (1992). The effect of subak system to the regional evaporation. Water Cycle and Water Use in Bali Island, Researches related to the UNESCO’s IHP in Japan.

Tekeuchi, K., Ao, T. Q., and Ishidaira, H. (1998). Introduction of block-wise use of TOPMODEL and Muskingum-Cunge method for the hydro-environmental simulation of a large ungauged basin. Hydrol. Sci. J., 44(4), 633-646.

Walter, K.M. (2000). Index to hydrological sites in New Zealand. NIWA Technical Report 73. 216 p.

Woods, R.A.; Sivapalan, M. (1999). A synthesis of space–time variability in storm response: rainfall, runoff generation, and routing. Water Resources Research 35: 2469–2485.

Woods, R.A. (1999). “Scaling in landscapes”. Presented at Workshop on Scaling in Hydrology, Co-operative Research Centre for Catchment Hydrology, Melbourne, June 1999.

Woods, R.; Biggs, B.; Snelder, T.; Duncan, M.; Weatherhead, M. (1999). “River habitat classification: what is the hydrological signature of a ‘source of flow’?” Presented at the New Zealand Hydrological Society Annual Symposium, Napier, November 1999 and to Sustainable Freshwater Ecosystems: the New Millennium, New Zealand Limnological Society and Australian Society of Limnology Joint Annual Conference, Wairakei, Taupo, November/December 1999.

Woods, R.; Duncan, M. (1999). “Modelling the cumulative effects of patchy, intermittent land use change on water yield and low flows at many locations in a river basin”. Presented at the New Zealand Hydrological Society Annual Symposium, Napier, November 1999.

Woods, R.A. (2000): Annual and seasonal water balance: 6 dimensionless numbers to quantify the roles of climate, soil, vegetation and topography, paper presented to the Fresh Perspectives Symposium, a joint UNESCO IHP meeting with the Meteorological Society of New Zealand, the New Zealand Hydrological Society and the New Zealand Limnological Society, Christchurch, New Zealand, November 2000.

Xia, J. (2001). An integrated hydro-ecological modelling approach applied to the Lake Bositeng Basin in China, Water International, 26(1), 105-118.

Xia, J. (2001). An integrated planning framework for management of flood-endangered regions in the Yangtze River Basin, Water International, 26(2),153-161 .

Xia, J. (2001). Eco-environment quality assessment: a quantifying method and case study in Ning Xia, arid and semi-arid region in China, IAHS Pub. No. 266 (Hydro-ecology: Linking hydrology and Aquatic Ecology) , UK, 41-48.

Xia, J., and K.Takeuchi (1999). Barriers to sustainable management of water quantity and quality, Hydrological Science Journal.44 (4), 503-505.

Xu, Z. X., Takeuchi, K., and Ishidaira, H. (2001). Precipitation variation due to climatic change in Southeast Asia and the Pacific region. Proceedings of the International Symposium on Achievements of IHP-V in Hydrological Research. Ha Noi, Viet Nam, Nov. 2001, pp.399-413.

Xu, Z. X., Takeuchi, K., and Ishidaira, H. (2002). A conceptually-based distributed rainfall-runoff model applied in arid regions. Proceedings of the International Conference on Urban Hydrology for the 21st Century, 14-16 October 2002, Kuala

Annexes


Lumpur, Malaysia, pp.45-60 Zhu, Y. S. (1997). Robust estimation in flood frequency analysis. Adv. in Wat. Sci. (in

Chinese), 8(2), 154-160. Selected Recent Proceedings and the Papers Included: Desa M., M.N., Ghazali, Z. and Sinnasamy, S. (Eds.) (1998). Proceedings of the 1st Asian Pacific FRIEND Workshop: Data Archive and Scientific Methods for Comparative Hydrology and Water Resources, Kuala Lumpur, Malaysia, 20-23 March 1998, IHP-V, Technical Documents in Hydrology, No. 1, UNESCO Jakarta Office, 242. Includes:

A. F. Embi: Hydrological data and information in Malaysia: Challenges to improve on quantity, quality and dissemination, pp. 1-7.

K. Takeuchi: Asian Pacific Friend Project – TSC Proposal, TSC proposals for scientific methods for Asian Pacific Friend Project, pp. 9-28.

R. James: Catalogue of Rivers – Directory of River Basins, pp. 29-33. R.P. Ibbitt and C.P. Pearson: Overview of New Zealand Hydrological network,

datebase and science projects, pp. 35-43. S. P. Abano: Establishment of water data archive in the Philippines, pp. 45-55. K. Chunkao: Establishment of water archive in Thailand, pp. 57-60. R. James: Asian Pacific Friend Database – Australian Node, pp .61-68. A. Kondoh, M. Tsujimura and K. Kuraji: Construction of world basin water budget

data base, pp. 69-75. K.H. Phuah and Jafri M., A.: Establishment of Malaysian Hydrological information

system for water resources Planning, development and management, pp. 77-83. T. Navuth: Hydrological Data Archive in Cambodia, pp .85-97. J. Loebis: Hydrological Data Archives of Indonesia, pp. 99-107. K. Soukhathamma Vong: Flood and Low Flow in Central Plain of Lao P.D.R, pp.

109-122. K. Takara and S. Ikebuchi: Frequency analysis of floods and droughts in the

framework of Asian Pacific friend, pp. 123-129. S.T. Lee and S. Lee: Water information system and scientific programme for Asian

Pacific friend in the Republic of Korea, pp. 131-139. T. Thuc: Monthly streamflow estimation for ungauged stations, pp. 141-151. L. Heng and T. Haixing: Comparative analysis of hydrological characteristics in

Lancang – Mekong river basis, pp.153-161. K.Takeuchi, T. Ao and H. Ishidaira: Modified topmodel application to large basins in

southeast Asia: Preliminary results, pp.163-172. T.Ismail, A.H.M. Kassim and A.A. Mamun: Simulation of runoff for an ungauged

catchment in Peninsular Malaysia, pp.173-183. Y. Ujihashi: Fetures prediction model in ten days hydrologic data analysis, pp.185-

198. A.W. Jayawardena and D.A.K. Femando: Rainfall anaomalies associated with el-nino

southern oscillation, pp. 199-207. D.R. Pangesti, Rahardianto and J. Loebis: Flood and low flow characteristics of Solo

River in Java Indonesia, pp. 209-220. R.K. Geroia: Operational Hydrology activities in Papua New Guinea, pp. 221-230.

Annexes


Proceedings of the Asian Pacific FRIEND and GAME Joint Workshop on ENSO, Floods and Droughts in the 1990’s in Southeast Asia and the Pacific, Hanoi, Vietnam, 23-26 March 1999. Asian Pacific FRIEND (Flow Regimes from International Experimental and Network Data), IHP-V, Technical Documents in Hydrology, No. 3, UNESCO Jakarta Office, 1999. Includes:

Alistair McKerchar: ENSO impact on hydrological regime of New Zealand, pp.I-1– 8. Ahmad Jamalludin bin Shaaban, Zelina binti Zaiton Ibrahim, Hong Kcc An and Jabir

bin Kardi : 1998 Langat Valley drought and telecommunication to ENSO, pp. I-9 – 18.

Dang Tran Duy: Statistical indices for determining El Nino and La Nina events, relation of which with annual amount of cyclone impacting on Vietnam, pp. I-19 – 23.

Bui Minh Tang: Relation of El Nino - Southern Oscillation with tropical cyclones in Vietnam, pp. I-24 – 27.

Hidayat Pawitan: ENSO impact on Indonesia rainfall, pp. I-28 – 37. Ivan Kuhnelivan and Lucinda Coates: Risk Assessment of ENSO related flood and

drought fatalities in Eastern Australia, pp. I-38 – 49. Francis Chiew: An overview of the potential use of ENSO based streamflow forecasts

to manage Australian Water Resources Systems, pp. I- 50. Jatawardena. A. W.: Prediction of ENSO indices by non – linear time series approach,

pp. I-51 Jun Matsumoto, Xueshun Shen, Atsushi Numaguti, Hiroaki Ueda and Kuranoshin

Kato: Large scale features during the GAME IOP after the largest El Nino of this century, pp. I-52 – 62.

Kang Bom Jin: El Nino and its effect on the drought in Korea, pp. I-63. Kazutoshi Kan: The relationship between precipitation and El Nino phenomenon, pp.

I-64 – 69. Khamthong Soukhathammavong: River flow variation in Lao PDR during ENSO

event, pp. I-70. Kim Tok Gil: Correlation of El Nino with summer weather of Korea, pp. I-71. Le Dinh Quang: Low latitude atmospheric Circulation and ocean – Atmospheric

interaction with ENSO, pp. I-72 – 77. M. Paul Mosley: Regional differences in the effects of El Nino/La Nina and low

streamflows and floods, pp. I-78. Manabu D. Yamanaka: El Nino impact over the maritime continent and Indonesian

forest fines, pp. I-79. Muntana Brikshavana: Impacts of ENSO phenomena in 1997/1999 on Thailand

climate, pp. I-80 – 92. Nguyen Dinh Ninh: ENSO and Drought in the 1997,1998 and 1999 in Vietnam, pp. I-

94 – 104. Nguyen Trong Hieu and Le Nguyen Tuong: Possibility of application of RAINFALL

software to study the relation between El Nino and rainfall in Vietnam, pp. I-105 –109.

Taikan Oki and Katumi Musiake: Global and regional Impact of ENSO on Hydrological cycles and water resources, pp. I-110.

Thaw San Hla: Impact of ENSO on climate and hydrological regime in Myanmar, pp. I-111.

Tran Thanh Xuan: Preliminary analysis of the influence of ENSO on river flow in

Annexes


Vietnam, pp. I-112 – 117. Tran Viet Lien: Relation between ENSO and Tropical Cyclone activity in the

Northwest Pacific and Vietnam, pp. I-118. FLOODS, DROUGHTS AND MITIGATION MEASURES

Akihiko Kondo, Juren Li, Kengo Sunada, Yasuyuki Ujihashi, Sheng Ping Zhang and Huxia Yao: Analyses on flood of 1998 Changjiang River in China, pp. II-1 – 10.

Akira Watanabe, Yoshihiro Tachibana, Yoshiaki Shibagaki, Sinya Ogino, Teruo Ohsawa, Kinji Furukawa, Yukinori Nakajima, Akimasa Sumi and Katsumi Mushiake: The characteristics of atmospheric structure in Northern Thailand before and after the onset of a South West monsoon, pp. II-11 – 19.

Dwikosita Karnawati, Sudarmanto, Suharyadi, H.Hendrayana and D.R.Pangesti: Development of GIS of Water Archive System in Merapi – Yogyakarta basin, pp. II-20 – 23.

Kong Xiangguang: Improving Xinanjiang model, pp. II-24. Kuniyoshi Takeuchi: World floods in the 1990’s, pp. II-25 – 29. Le Trung Tuan and So Kazama: Evaluation of lumped model parameters using GIS,

pp. II-30 – 38. Michiharu Shiba and Xavier Laurenson: Real time stochastic dynamic stage and

discharge estimates for a channel network, pp. II-39 – 50. Nguyen Viet Thi: The impact of ENSO phenomenon on annual flood peaks of the

Red River and the Cuu Long River, pp. II-51 – 56. Roslan Bin Zainal Abidin and Tew Kia Hui: Rainfall energy production in relation to

soil erosion, pp. II-57 – 63. Shidawara Masatoshi: A preliminary report on disaster by Hurricane Mitch in

Honduras, pp. II-64 – 68. Shie Yui Liong, Wee-Han Lim, Toshiharu Kojiri and Khadananda Lamsal: Infilling

missing data strategies in flood stricken Bangladesh, pp. II-69 – 100. Srikantha Herath: Flood forecasting with Distribute Hydrologic Models Using WWW,

pp. II-101. Van-Nguyen-Van Thanh and Ganesh Raj Pandey: New statistical approaches to

regional estimation of floods, pp. II-102 – 113. Vu Van Tuan: The influence of climate change to river runoff in humid tropical zone

A case study in Vietnam, pp. II-114 – 118. Cao Dang Du: Flood and flash flood in Vietnam, pp. II-119 – 125. ZhangLiPing Xiajun: The international variability of SCSSM and its influence on

climate in China, pp. II-126. ASIAN PACIFIC FRIEND RESEARCH PLAN PROPOSALS

Daud M.Zalina, Nguyen V.T.V, Kassim M,A.H. and DesaM M.N.: Statistical modelling of extreme rainfall process, pp. III- 1 – 10.

Fumio Yoshino: Comparison of long term annual run-off in World rivers and its critical discussion, pp. III-11 – 19.

Hua Jiapeng and Liang Zhongmin: A new method in determining design flood hydrograph for small basins, pp. III-20 – 27.

Joerson Loebis: Toba lake water level draw down and ENSO, pp. III-28 – 37. Kaoru Takara: New methods in frequency analysis, pp. III-38. Kimchul: Analysis on flood damaged areas using remote sensing data, pp. III-39.

Annexes


Li Zhijia and Li Jian: A semi-self adoptive updating model for complicated channel flood routing and forecasting, pp. III-40 – 46.

Liang Zhongmin and Hua Jiapeng: A robust method in flood forecasting analysis, pp. III-47 – 54.

Maino Virobo: Static low flow Hydrology of uncontrolled catchments: A case study on Ewogoro and Eilogo catchments, pp. III-55.

Sae-Chew Winal: Flood warning system for Sadas Hatyai region, pp. III-56 – 65. So Kazama: Comparison of water balance in some tropical basin, pp. III-66 – 73. Xia Jun and Zhang LiPing: The research on the method of long term forecast on the

heaviest flood in China, pp. III-74. Nguyen Kien Dzung: Applicability of sedimentation models to simulate deposited

sediment in reservoirs in Vietnam, pp. III-75 – 79. Thuc, T (ed.) (2001). Proceedings of the International Symposium on Achievements of IHP-V in Hydrological Research. Ha Noi, Viet Nam, 19-22 November, 2001. IHP-V Technical Documents in Hydrology No. 8, UNESCO Jarkarta Office, 2001. 431. Includes:

Katumi, M.: Hydrology and water resources in Monsoon Asia – Proposal of a new hydrological region “warm-humid tectonic zone”, 1-7.

Takeuchi, K.: Flood control investment and damage potential: A vicious cycle? 9-13. Huynh, L. B., and Thuc, T.: Flood disaster in Viet Nam: 15-22. Jayawardena, A. W.: Coupling of land surface and river runoff models: Application to

Mekong River basin, 23-31. Chuong, L. T., Thuan, L. V., and Khoa, V. A.: Dam breach flood wave simulation in

reservoir cascade of Lai Chau – Son La – Hoa Binh, 33-38. Du, C. D., Lu, T. D., and Truong, D. X.: Evaluation of design flood on rivers of the

central Vietnam, 39-44. Du, C. D., Nga, T. B., Hang, D. T., and Ha, N. T.: Flood and inundation on Tra Khuc

River, 45-49. Dutta, D., and Herath, S.: Flood modelling experiences in Mekong River basin, 51-59. Bonn, F., Sahebi, M., St-Onge, L., Arsenault, E., Cu, P. V., Coulombe-Simoneau, J.,

and Smyth, J.: Spaceborne observation of catchment surface changing conditions generating excess runoff, erosion and flood risk downstream, 61-76.

Liu, H., Geng, L. H., Yan, Z. J., and Zhong, H. P.: Option of sustainable water resources use in the western Inner Mongolia of China, 77-85.

Haga, H., Ebisu, N., and Ogawa, S.: Long-term changes of the rainfall-runoff in the fire damaged forest basin, Japan, 87-95.

Hoai, N.: Overview of legal and institutional arrangements for water environment management in Viet Nam, 97.

Huynh, L. B., and Long, B. D.: Catastrophic flood, inundation in early November and early December 1999 in the central Viet Nam, 99-114.

Huynh, L. B., Hoa, L. T. V., Long, B. D., Thuc, T., Duc, B. V., Mien, L. V., Duc, P. V., and Ha, L. T.: Flood and inundation in Cuu Long River delta in the year of 2000, 115-125.

Loebis, J.: Comparative hydrological study on design flood between river in Indonesia and New Zealand, 127-133.

Khai, N. H.: Research on flash flood in Dinh River basin, 135-144. Khanh, D. V.: Application of conceptual rainfall runoff model for evaluation of

human activities influence on flood flows, 145-158.

Annexes


Masoud, A. A., Raghavan, V., Masumoto, S. and Shiono, K.: Stream network and basin boundary extraction using grass GIS in Safaga area, Red area coast of Egypt, 159-165.

Phuc, N. H.: Flood management and mitigation in Vietnam, 167-170. Quang, L. D.: Typhoons, floods in the central Viet Nam, 171-180. Jha, R., Pradhan, N. R., and Takeuchi, K.: Applicability of BTOPMC model in

Nepalest catchment, 181-189. Ibbitt, R., and Woods, R.: Testing an unclibrated rainfall-runoff model using data

from the Mahurangi research basin, New Zealand, 191-204. James, R. A., Desa, M. M. N., and Sahar, S.: Upgrade of the Asian Pacific FRINED

water archive, 205-213. Kazama, S., Hagiwara, T., and Sawamoto, M.: Temporal and spatial inundation

pattern revealed by numerical simulation of the 2000 flood in the lower Mekong, 215-220.

Son, D. H.: Bubble plume destrification: Large eddy simulation, 221-225. Lee, S.: Rainfall-runoff characteristics of discriminated hydrologic zones in Southeast

Asia and the Pacific river basins, 227. Herath, S.: Spatial data sets for distributed hydrological modelling in the Mekong

basin, 229-238. Pratishthananda, S.: Comparative study on two extreme floods at Nakhonsawan,

Thailand, 239-248. Funada, S., Ishidaira, H., and Takeuchi, K.: Application of complementary method for

estimating areal actual evapotranspiration in Southeast Asia and the Pacific, 249-258.

Sopharith, T.: Simple flood forecasting model for Cambodia, 259-266. Thanh, L. D.: Potentiality of heavy floods on Huong River basin, 267-271. Thi, N. V., and Hoa, L. T. V.: Inflow forecast for Hoa Binh reservoir, 273-279. Thuc, T., Anh, L. T., and Huong, H. L.: Flood forecast and inundation computations

for the Thu Bon River system, 281-287. Daniel, T. M.: Using ANNs to develop regionalisation methods for streamflow

estimation in Southeast Asia and the Pacific, 289-309. Trung, L. D.: Implementation of sustainable development and management in

integrated planning of Quan Lo – Phung Hiep project, 311-318. Tuan, V. V.: Water resources and climate change, 319-328. Nguyen, V.-T.-V., and Han, S.-Y.: On stochastic modelling of daily rainfall process,

329-344. Raghavan, V., Herath, S., and Dutta, D.: An integrated based water infrastructure

inventory system, 345-352. Kong, X. G., and Li, Z. J.: General unsteady flow software of open channel networks,

353-360. Zhang, X. N., Liu, J. F., and Jin, L. Y.: An expert system for flow routing on a river

network, 361-376. Xuan, T. T.: The impact of El Nino – Southern Oscillation on river runoff in Vietnam,

377-382. Chen, Y. F,: Comparison of conventional method and stochastic simulation method to

calculate design flood – control storage, 383-390. Li, Z. J.: Real time channel flood stage forecasting coupling with Kalman filter

updating model, 391-397. Xu, Z. X., Takeuchi, K., and Ishidaira, H.: Precipitation variation due to climatic

change in Southeast Asia and the Pacific region, 399-413.

Annexes


Dac, N. T.: A mathematical model for BOD/DO simulation and its application to a development project in Ho Chi Minh city, 415-422.

Tien, P. V.: Huong River basin – The heavy storm, high flood area and design flood calculation for Ta Trach reservoir project, 423-431.

Desa, M. M. N., Shahar, M. S., and Sarvamudthy, S. (Eds.) (2002). Proceedings of the International Symposium on Comparative Regional Hydrology and Mission for IHP Phase VI of UNESCO, Kuala Lumpur, Malaysia, 14-16 October 2002, 238. Includes:

Takeuchi, K.: Challenge and achievements of the RSC: Potentials for the future, 1-9. Kojima, T., Takara, K., and Tachikawa, Y.: Comparison of three flood runoff models

in the Shonai River basin, Japan, 10-24. Abustan, I., Mohd, N. D. M., and Wahid, N. A.: Testing the suitability of SWMM as

alternative management practices in Malaysia: the cases of four catchments, 25-34. Kimaro, T. A., Tachikawa, Y., and Takara, K.: Development of a hydrological model

for predicting the effects of land use changes at Yasu River basin, 35-44. Xu, Z. X., Takeuchi., K., and Ishidaira, H.: A conceptually-based distributed rainfall-

runoff model applied in arid regions, 45-62. Yamamoto, N., Ishihara, T., Ishidaira, H., and Takeuchi, K.: Estimation of snow

water equivalent in the upper Tone River basin, 63-73. Ghumman, A. R., Shah, S. M. S., and Abulohom, M. S.: Simulation of catchment

runoff in Pakistan, 74-85. Rakhecha, P. R., and Krishnakumar, G.: Determination of design storms in India, 86-

95. Pangesti, D. R., Sumaryono, A., and Sukatja, B.: Flood forecasting and warning

system of debris flow in volcanic area, 96-102. Tingsanchali, T.: Comparison of combined deterministic and stochastic models for

daily flood forecasting for Thailand, 103-116. Malek, M. B. A.: Watershed analysis – rainfall-runoff model, 117-126. Shrestha, R. K., Yasuto, T., and Kaoru, T.: IC ratio concept in distributed

hydrological modelling for optimal performance, 127-137. Thuc, T., and Duc, B. V.: Hydraulic computations of assumed failures of Hoa Binh

and Son La dams, 138-143. Khaled, A.-F., Mohamed, A.-S., and Joji, A.: Geophysical logging of boreholes in

clastic aquifer for the determination of electrical earthing depth, 144-148. Hars, T.: Environmental impact assessment of the utilised thermal water in Hungary –

method of WQMCAL, 149-158. Mirsaidov, U., and Normatov, I. Sh.: Economical, social and political aspects of water

utilization in Central Asia, 159-164. Ebtisam, A.-O., and Mohamed, A.-S.: Combating desertification through water

resources management, 165-168. Kawamura, A., Jinno, K., and Eguchi, S.: Statistical and long-term characteristics of

Southern Oscillation, 169-178. Liu, H., Mao, F. L., and Wu, Y. X.: Water resources allocation, monitoring and

operation for water transfer project in northern Jiangsu Province, 179-182. Hehanussa, P. E., and Haryan, G. S.: Flood and drought extremes, governance

decentralization, and warm of river basins, an Indonesia experience, 184-189. Kondon, A., and Kojiri, T.: Hydrological regions in Monsoon Asia, 190-201. Lai, F. S., and Tan, A. T. W.: Soil erosion estimations using Geographic Information

System and the Universal Soil Loss Equation on the Muda catchment, Kedah,

Annexes


Peninsular, 202-209. Lai, F. S.: Suspended sediment yield changes resulting from forest harvesting in the

Sg. Weng experiemental watersheds, Kedah, Peninsular Malaysia, 210-215. Kumaran, S., and Lai, F. S.: Hydrology of a lower Montane catchment in Fraser’s hill,

Pahang, 216-224. Irawan, D. E., and Deny, J. P.: Geological mapping and groundwater physical-

chemical properties characterization – an approach to spring recharge area conservation, 225-231.

Hadi, K., and Al-Awadi, E.: The impacts of the climate conditions on the aquifer local recharge in Kuwait, 232-238.

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