9th International Conference on Urban Drainage Modelling

Belgrade 2012

1

Historical Development of Hydroinformatics Tools in Bangladesh and Challenges and state-of-the-art in Urban Drainage Modelling David M. Khan

1; S. M. Mahbubur Rahman

2

1 Associate Specialist, Institute of Water Modelling (IWM), House#496, Road#32, New DOHS,

Mohakhali, Dhaka-1206, Bangladesh, mail: dmk@iwmbd.org, Web: www.iwmbd.org 2 Director, Water Resources Planning Division, Institute of Water Modelling (IWM), House#496,

Road#32, New DOHS, Mohakhali, Dhaka-1206, Bangladesh, mail: smr@iwmbd.org

EXTENDED ABSTRACT

Hydroinformatics has become a major discipline for water resources professionals

worldwide. In the last few decades it has developed immensely and had profound influence

on how these professionals practice engineering. It helped building the bridge between

engineers and non-engineering experts. Development activities are not only considered for

economic viability, but now it is also possible to take into account multi-sectoral

considerations to make projects sustainable.

Modelling activities in Bangladesh was first carried out in late 1970s to early 1980s, when

numerical models were first applied to countrys two sea ports, Chittagong and Chalna (now moved to Mongla). In the projects studies were carried out on river hydraulics,

morphology, river training, dredging and navigation with the modelling technology.

Later in 1986, Surface Water Simulation Modelling Programme (SWSMP) under Master

Plan Organisation (MPO) began mathematical modelling in the water planning process for

the effective control and utilisation of water resources in Bangladesh. The SWSMP was

carried out in three phases. In the phase-I programme, the System 11 modelling system by

DHI was used to study development scenarios, compare the performance of various modes

of development and determine the main characteristics of water development. The SWSMP

project document described the South-East Region of Bangladesh as a pilot area for

development of hydraulic simulation capabilities, with particular reference to many finished

and ongoing projects. In addition, a General Model for the major river system of

Bangladesh was also developed by a joint team of MPO and BUET professionals.

SWSMP-II commenced in December 1989 and completed its four year programme in

November 1993. The need for model development in Bangladesh was given added impetus

following two consecutive disastrous floods in 1987 and 1988. The implementation of

Flood Action Plan (FAP) under the Flood Plan Coordination Organisation (FPCO)

reinforced this need. By the end of SWSMP-II, four new Regional Models were developed

and only a small section of the country remained outside these models. SWSMP-III

commenced from January 1994 for a further three year period until December 1996, in

which the remaining part was modelled and also witnessed the introduction of new

modelling technologies: water quality models, two dimensional coastal and river models,

and an advanced hydrological and ground water models.

The first urban drainage model in Bangladesh was developed in 1997 for Dhaka City,

capital of the country. Dhaka has serious problems related to urban flooding and water

9th International Conference on Urban Drainage Modelling Belgrade 2012

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logging. The situation was highlighted in September 1996 when residences experienced

ankle to knee deep water on the streets throughout the City. A study was initiated in which

a combined approach of physically based modelling and GIS analysis was carried out. The

urban drainage system was structured by MOUSE for the basis of two networks, one

simulating the free-surface flow over the streets and one for the sewer pipe system.

In recent years urban drainage models are utilized to assess climate change impact and to

device adaptation options. The urban drainage model developed for Khulna, third largest

city of Bangladesh, was used to strengthen the resilience of drainage system for climate

change conditions in 2050. Using the model it was possible to develop socio-economic as

well as climate change scenarios for the future and take into account economic, social and

public health impact of the changed conditions based on which the adaptation measures

were developed.

Urban drainage modelling has also evolved with the evolution and development

Hydroinformatics. Models are getting better reflecting the real flood conditions even in fine

resolution. The traditional 1D models are now getting coupled with 2D models which

enables more realistic analysis of overland flows. The 1st generation models which started

solving simple equations has moved on to 4th generations models which can be used to

integrate urban drainage models with tools to provide decisions based economical,

environmental, ecological, socials considerations. While technology has advanced in urban

drainage modelling, there still exists the problem with lack of flood data, accurate definition

of rainfall inputs, understanding of uncertainties involved in applying flood model, limited

experience with real time flood forecast models, which are some of the challenges facing

the discipline.

References

1. Danida Ministry of Foreign Affairs, Demark, Project Completion Report: Surface Water

Simulation Modelling Programme (SWSMP), Bangladesh, 1997.

2. Apirumanekul, C., Mark, O., Modelling of Urban Flooding in Dhaka City, Proceedings

4th

DHI Software Conference; 101-8, 2001.

3. Asian Developement Bank, Adapting to Climate Change: Strengthening the Climate

Resilience of the Water Sector Infrastructure In Khulna, Bangladesh; 278-8, 2011.