SALTWATER INTRUSION STUDYSALTWATER INTRUSION STUDYIN BOHAI COASTAL ZONE

Hongwei LiuHongwei Liu

Tianjin Center, China Geological Survey

ContentsContents

d i1. Introduction

2. Physical backgroundy g

3. Legal and institutional framework

4 Problem descriptions4. Problem descriptions

5. Research questions and objectives

6. Data availability

7 Training needs and capacity development7. Training needs and capacity development

8. Expectations from the project

1 Introduction Study area1. Introduction Study area

SWI in China

• DistributionDistribution

• The Earliest Site:

Dalian City

• Most Serious Site:• Most Serious Site:

Laizhou Bay Area

• Study Area:

L i h B ALaizhou Bay Area

1. Introduction

• Social and economicsThe study area covers almost 

5000 km2 in Shandong province,

eastern Chinaeastern China .

Population: 2 million.

GDP: 80 billion RMB

(about  10 billion EURO).

Agriculture:

( d h )(crops‐cotton, maize and wheat).

Industry: marine chemistry, machinery manufacture and ytextile.

Irrigation: groundwater and surface water Location mapsurface water. Location map

1 Introduction1. Introduction• (Ground)Water resources development and managementmanagement

Water resources development:

- Mean annual amount of water resources: 744.4 million m3.Mean annual amount of water resources: 744.4 million m3.

- Available amount of surface water resources: 212.3 million m3.

- Amount of groundwater exploitation: 532.1 million m3.

P ti f diff t- Proportion of different purpose:

Irrigation

Irrigation amount:  87％

Industry and drinking amount: 13 ％

Irrigation

Industry anddrinking

Irrigation in salt-water area: surface water.Irrigation in salt water area: surface water.Irrigation in fresh-water area: groundwater (majority) and surface water (minority).

1 Introduction1. Introduction

•(Ground)Water resources development and(Ground)Water resources development and

• management

Management measures ：

- Increase the sources of water (Precipitation, guest-water), water i (A i lt i d t d i ki ) R ti lresources saving (Agriculture, industry, drinking) , Rational

exploitation of groundwater.

- Project of water retaining dam in the river.j g

- Artificial recharge and setting up a freshwater barrier ,make full use of the fresh water from Yinhuangjiqing channel.

P j t f d d d i t i i d t t SWI- Project of underground dam in estuaries in order to prevent SWI.

- Utilization of brackish water .

1 Introduction1. Introduction• Problems and challenges- Amount of water resources could not meet the demand of economicAmount of water resources could not meet the demand of economic

development.

- Saltwater intrusion occurred because of overexploitation.

S lt t i t i h d i fl d i lt i d t d d i ki- Saltwater intrusion had influenced agriculture, industry and drinking.

• Previous and on‐going projects and researchesH d l i l d h d h i l t di ( XUE 1998 N ji- Hydrogeological and hydrogeochemiscal studies.( XUE,1998a. Nanjing University)

- The simulation of hydrodynamic field under exploited condition with MODFLOW. (Shandong province.2006a .SECTION)

- Monitoring and simulation of seawater intrusion in typical coastal area. (CIGEM ,CGS. 2011-2013a)(CIGEM ,CGS. 2011 2013a)

- The geological environment investigation and assessment in the Bohai Economic Zone .(CGS. 2012-2014a)

G l i l i t i ti ti d t i L i h B- Geological environment investigation and assessment in Laizhou Bay area.( CGS.2013-2015a)

2 Physical background2. Physical background

• geomorphologyHigher in south and lower in north,

Ground elevation

South:

North:

30m

5m

l

Average slope : 0.47‰.

Alluviual → Diluvial → Marine sediments

• geologyIt contains a series of Cretaceous to Recent sediments that overlie the Palaeozoic basement

LEGEND ： 1.Low mountain;2.Hills;3.Intermountainous plain （ IV1-Denudation plain;IV2-Alluvial and diluvialplain）;4.Inclined piedmont alluvial and diluvial plain;5.Micro-inclined plain（VI1-Alluvial and diluvial plain by yellowriver;VI2-Alluvial and marine plain;VI3-Marine plain);6.Marine and diluvial plain of deltas ； 7.Boundary ofgeomorphology；8.Boundary of secondary geomorphology；9.Sandy soil of Quaternary ;10.Sandy clay of Quaternary；11.Clay of Quaternary；12.Loess of Quaternary；13.Granite；14.Boundary of lithology；15.Rivers；16.Faluts；

basement.

Quaternary sediments(thickness)

South:

North:

30-50m

300 400m

Geomorphological and Geological map

y Q y Q y y gy17.Alluvial-diluvial fan；18.Boundary of Bohai coastal zone；19.Boundary of study area.

(thickness) North: 300-400m

2 Physical background2. Physical backgroundMean annual precipitation 630 mm

A l i it tiAnnual precipitation

250

300

(mm)

50

100

150

200

Precipitation(

Monthly precipitation (2011a)

0

1 2 3 4 5 6 7 8 9 10 11 12

Month

Monthly precipitation (2011a)

2 Physical background2. Physical backgroundAverage annual temperature 12

12.5

13

13.5

re(℃

)

11

11.5

12

Temperatur

Annual temperature

10.5

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Year

15

20

25

30

re(℃)

-5

0

5

10

1 2 3 4 5 6 7 8 9 10 11 12

Temperatur

Monthly temperature

(2011a)

-10

Month

2 Physical background2. Physical background

Average annual evaporation 1640 mmAverage annual evaporation 1640 mm

150

200

250

on(mm)

50

100

Evaporatio

0

1 2 3 4 5 6 7 8 9 10 11 12

Month

Monthly evaporation (2011a)

Drought character:Mean annual precipitation(630mm)Average annual evaporation(1640mm) ＞

2 Physical background2. Physical background

Aquifers and aquitardsAquifers and aquitards

Hydrogeological cross‐sections

2 Physical background2. Physical background

Main riversMain riversWeihe river, Yuhe river, Bailanghe river  and Mihe river.

Channel

Yinhuangjiqing channelYinhuangjiqing channel.

ReservoirsXiashan reservoir,Bailanghe reservoir.

Catchments map

3 Legal and institutional framework3. Legal and institutional framework

Water laws and regulations

-Water resources (surface water and groundwater) belong to state

Water laws and regulations

state.

-Unified management of water resources.

The state encourages organizations and individuals to-The state encourages organizations and individuals to develop and utilize water resources by law, and protect their legal rights and interests.

-License system of fetching water, charge system of water resources, and fines to overexploitation.

I l t t i t t i d- Implement water-saving system, water-saving reward.

- Protection, modification and utilization of water resources, fines to pollutionfines to pollution.

3 Legal and institutional framework3. Legal and institutional frameworkOrganizational set-up for (ground)water resources management.

Management scope on water resources are given by the government in China. The Ministry of Water Resources implements comprehensive management for water resources. Other Ministries and its’ subsidiary bodies implement classified survey and supervise on water resources. Ministries and functions on water management are as follows:

Organizational diagram

4 Problem descriptions4. Problem descriptionsGroundwater depletion

Overexploitation

FunnelsFunnels

SWI

Water level of shallow groundwater （m）Legend：1.Line of groundwater depth；2.Line of shallow groundwater level；

3.Boundary of mount and plain; 4.Rivers；

Map showing the cone of depression

y p ; ；

4 Problem descriptions4. Problem descriptions

Groundwater depletionp

Shallow groundwater level curveRelationship among groundwater level, exploitation and pricipitation

Groundwater level hydrograph showing decreasing trend.

4 Problem descriptions4. Problem descriptionsSaltwater intrusion

Owing to the concentration of human habitation, urbanization and agricultural activity, increasing demand for groundwater has caused a gradual increase in saltwater intrusion over recent years.

GUANGRAO,163.7

SHOUGUANG,137.8

ZHAOYUAN, 24

LONGKOU ,131.7

20

30

40

50

ion  area

0*km

2）

te（

km2/a）

HANTING,100.5LAIZHOU,

380.6

0

10

Intrusi

（100

Intrusion ra

1976-1979

1980-1989

1989-1993

1993-2005

Y

Intrusion acreage

CHANGYI,136.5PINGDU, 82.9

SWI occurred in several monitoring wells in the coastal area of Shouguang, 

Years Intrusion rate

Hanting and Laizhou city in 1976.

From 1970s to prophase of 1980s, the rate of intrusion was very slow.

Si th i th i t i b t d i th idSince the excessive pumpage, the intrusion became aggravated in the mid and late 1980s. 

Generant process of SWIGenerant process of SWI

H d t P P th

Brine layer Ancient riverwayExploitation

Headstream Power Paths

SWI

4 Problem descriptions4. Problem descriptionsSaltwater intrusion

The survey results in 2011a

4 Problem descriptions

North

4. Problem descriptions

North

Cl-

Cl SO 2

TD

S

Cl-·SO42-

HCO3-·Cl-

HCO3-

South

4 Problem descriptions4. Problem descriptionsThe salt‐fresh water interfaces

Interface moving2002a-2005aFaster:

Interface moving

inland 2005a-2007aLower:

ChangyiCity:Exploitation

Present locationChangyi

about 28km--sea

City:

Distance:

5 Research questions and objectives5. Research questions and objectives

• Research questions for saltwater intrusionResearch questions for saltwater intrusion

(a).Boundary of saltwater intrusion, and multilayered 

(b). Relationship between river‐water and groundwater,

monitoring of SWI.

( ) p g ,and monitoring of (ground)water level.

( ) l l l ff h h d d(c). Environmental geological effects which were induced by human activities and climate changing.

(d). Relationship between vegetation ( crops, irrigation mode ) and groundwater ＆ saline land improvement.g p

5 Research questions and objectives5. Research questions and objectives

Obj i f l i i d• Objectives for saltwater intrusion study

(a) Refined hydrogeological studies in SWI area(a). Refined hydrogeological studies in SWI area.

(b) E i l d i l i i f d(b). Economical and practical monitoring for groundwater.

(c). Forecast model suitable for study area.

(d). Prevention and control technology of SWI.

6 Data availability6. Data availability• Data for mapping saltwater intrusion

l ifi i d d li i f if– Classification and delineation of aquifers

Single‐layer  to multi‐layers structure.

– Number and distribution of groundwater level and qualityNumber and distribution of groundwater level and quality monitoring wells in each aquifer.

5 shallow monitoring wells, 1 multi‐layered monitoring well.

– Sampling for groundwater salinity study

2 times/a  (profile).

Time series of salinity increase– Time series of salinity increase

2001‐now  (discontinuous), 2012‐2015(continuous)

– Contour map of salinityContour map of salinity

2005a, 2011a

6 Data availability6. Data availability• Data for mapping saltwater intrusion

f l– Sources of saltwater

Modern seawater and ancient seawater (brine).

– Fresh/salt water interfaces (determined by geophysical surveysFresh/salt water interfaces (determined by geophysical surveys, water samples, and monitoring data)

Geophysical surveys: 2011a(3 profiles), 2013‐2015 (more)

– Impacts of saltwater intrusion

Agriculture: reduction of yield, useless of irrigation wells.

Industry: cost increase decline of production qualityIndustry: cost increase,  decline of production quality.

Health: health risk.

– Modeling of saltwater intrusionModeling of saltwater intrusion

Prediction simulation of hydrodynamic field in local area (2006a).

Lack of modeling of SWI for regional area.

7. Training needs and capacity development

• Number of experts and experiencesNumber of experts and experiences6 experts  for SWI √

• Required training courses• Required training courses

Modeling.  Advanced monitoring methods？

• Set‐up of groundwater monitoring networks

Profile monitoring: CTD diver, water samples √g p

Training need 

• Instruments for groundwater monitoringInstruments for groundwater monitoringCTD diver √ Water quality multi‐probes (HYDROLAB) √

Training needg

7. Training needs and capacity development

S f f d d li• Software for groundwater modelingMODFLOW √  Other prevalent or applied software?

• Construction of groundwater modelsTraining need

• Measures for mitigating groundwater problemsTraining need

• Groundwater management and governanceTraining need (Pay more attention to methods of technology)g ( y gy)

8 Expectations from the project8. Expectations from the project• How should project seminars and workshops be organized?

• What assistances are required from the project?q p jAdvanced methods and theory.

• What results are expected from the project?What results are expected from the project?Improve the study level for the study area, and finish  comparative 

research with cooperative countries.

• What do you want to learn from other countries?Working experiences.  Working thoughts. g p g g

• What experiences do you want to share with other countries?countries?

Geophysical survey. Monitoring system.

Thank you for yourThank you for your attention!attention!

Mr. Ma Zhen

• 25 employees in the department• 2 professors 5 PHDs 11 masters• 4 research groups: water cycle evolution & water

resources assessment, SWI & hydrochemistry, land subsidence & geohazard, Quaternary geology

Geophysical survey

Proposal of SWI monitoringProposal of SWI monitoring

Remote sensing Air

Geophysical exploration

Physiognomy

Geophysical exploration

Vegetation

SWI Monitorsystem

PhysiognomySurface

RiversSoil

Under-ground

Ph i l h i tg

Physical chemistryof water in well

Instrument in well

Period: 2-3 times/a for three years