1. Ganges Basin Development Challenge

2. Ganges Basin Development Challenge
Objective: Improve resource productivity and increase the resilience of
agriculture and aquaculture systems of brackish coastal areas of the Ganges

3. What the Ganges BDC Hopes to Achieve?
Goal:
Reducing poverty, increasing resilience, through improved water governance and
management & intensified and diversified agricultural and aquacultural systems
in brackish water of the coastal Ganges.
Objective:
Improve resource productivity and increase the resilience of agriculture and
aquaculture systems of brackish coastal areas of the Ganges.

4. Geographical Setting
of Bangladesh
Mayanmar

5. Ganges Basin:
Ganges Basin Area
= 1,087,300 sq. km

6. Study Area:
Ganges Dependent Area
in Bangladesh
Project Target Area:
Coastal Zone of the Ganges basin in
Bangladesh except the Sundarbans
Coastal Divisions:
Barisal: Patuakhali, Barguna, Jhalakati &
Pirojpur districts
Khulna:
Khulna & Satkhira districts

7. Problems and Challenges in the Coastal Region of Bangladesh
Salinity intrusion
Sea level rise
Decrease in precipitation in dry season
Salinity intrusion
Salinity Intrusion Increase in precipitation in monsoon
Increased frequency of tropical cyclone
Added siltation on the
drainage route
Flood
Cyclone
Water logging

8. Coastal Polders in Bangladesh
In the early sixties and seventies, 125 polders (of which 49
are sea-facing) were constructed to protect low lying coastal
areas from tidal flood & salinity intrusion.

9. Drivers of Change: Participatory Approach
DRIVERS PRESSURE/CONSEQUENCES
Demographic/Societal Pressure on Space
Population growth Water demand & use
Dietary patterns of the population Loss of biodiversity and wetlands
Land use change including increase area under rice cultivation
Urbanization
Economic/Trade Shift in land use
Economic develpopment in coastal zone (change in per capiata Water Demand
income) Roads, railway & ports
Market value of agricultural products Water pollution
Water pricing and increase
Industrialization
Political/Institutional/Legal Improved Irrigation and drainage system
Water policy (national and regional) Flood protection system
Change in water governance and institutions Water availability in the dry season
Water sharing mechanisms between the riparian parts of the basin
Changes in water management practices
Change in trans-boundary flow
Environmental/Climate Change Fresh water shortage, Salinity intrusion
Sea level rise due to Climate Change Flood Hazard,Coastal/fluvial erosion
Changes in precipitation and temperature due to Climate Change Change in Sediment balance
Subsidence Cyclone & Storm surge with higher
frequency and intensity
Technological/Important Innovations Enhanced knowledge and use of HYV
Changes in aquaculture and agriculture intensification Enabling environment for agricultural
Water Use change; Water infrastructure development development

10. Questionnaire
Name
Age
Gender Male Female
Occupation
Please indicate how do you think the external drivers will affect water resources of your area/coastal region of
Ganges basin ?
Score (1-5)
2. To a very limited
significant extent
4. To a significant
3. To a moderate
5. To a very
extent
extent
extent
1. No
Sl External Drivers Remarks
1 Do you think the pressure of population
growth on water resources will continue in
the future?
2 Is market value an important factor in crop
divesification?
3 Will sea level rise reduce freshwater
availability and land availability for
agriculture?
4 Will decrease of rainfall in the dry season
and increase in the monsoon renderadverse
impact on water resources?
5 Does political change or institutional issues
cause any change in water management?

11. Percentage
Population Growth
6.5%
Changes in Water Mgt
Sea level rise
6.1% 5.9%
Land use change
Water Sharing
5.7% 5.7%
Transboundary flow
Aquaculture intensification
Economic Develpopment
Urbanization
Water infrastructure…
5.5% 5.4% 5.4% 5.4% 5.4%
Changes in precipitation
5.2%
Water Policy
4.8%
Industrialization
Water Governance &…
4.6% 4.6%
Water Use change
Preliminary Results of Questionnaire Survey
Market Value of Agro Products
4.4% 4.3%
Changes in temperature
4.2%
Dietary patterns
3.2%
Water Pricing & Insurance
2.8%

12. Methodology:
Generation of climate change scenario
(100 or 200 km grid)
(20 to 50 km grid)
High resolution
regional climate
change surface

13. Ganges, Brammaputra and Meghna Basin Model
Bangladesh rivers receive runoff from a catchment
of 1.72 million sq. km, around 12 times its land area
Brahmaputra Basin
552,000 sq.km
CHINA
INDIA
BHUTAN
Ganges Basin
1,087,000 sq.km
INDIA
BANGLADESH
Meghna Basin
82,000 sq.km
BAY O F BE N GAL

14. Methodology: Upstream Boundaries (Q, Sal = 0ppt)
Water flow and salinity
model for
south-west region of
Bangladesh
Rainfall
Evaporation
& Other loss
We need:
-Cross-section of the rivers
- Structure information
- Rainfall and evaporation data
- Time-series WL, water flow and salinity
data (from primary/secondary sources
and calibrated Bay of Bengal model)
- Measured WL, water flow and salinity
data for calibration and validation
Downstream Boundaries (WL, Sal)

15. Methodology:
Land-use management practices and water inflow:
SWAT Model:
A process-based continuous hydrological model that predicts the impact of land
management practices on water, sediment and agricultural chemical yields.
Water balance equation:
SWt = SWo +
Where,
SWt = final soil water content (mm)
SWo = initial soil water content (mm);
t= time (days)
Rday = amount of precipitation on day i (mm)
Qsurf = amount of surface runoff on day i (mm)
Ea = amount of evapotranspiration on day i (mm);
Wseep = amount of percolation on day i (mm)
Qgw = amount of return flow on day i (mm)

16. Hydrologic Trend Analysis in the Study Area:
Trend Analysis of Upstream River Discharge
Hardinge Bridge on the Ganges • Increasing trend of
90000 annual maximum flow
80000
• Decreasing trend of
70000 annual minimum flow
60000
Discharge (m3/s)
50000
40000
30000
20000
10000
0
1930 1940 1950 1960 1970 1980 1990 2000 2010
Max Q Min Q Average Q
Linear (Max Q) Linear (Min Q) Linear (Average Q)

17. Hydrologic Trend Analysis in the Study Area:
Trend Analysis of Downstream Water Level
Hiron Pointon the Pussur River
Hiron Pointon the Pussur River • Rising trend of water
4 level near the sea
4
3
3 The increase of maximum
2
water level is 6 cm/yr at
Water Level (mPWD)
Water Level (mPWD)
Hiron Point in the last 10
12
years.
0
1
-1
-2 0
1980
1999 1985
2001 1990
2003 1995
2005 20002007 2005 2009 2010
Max of WL Max of WL of WL
Min Linear (Max of WL)of WL
Average
Linear (Max of WL) Linear (Min of WL) Linear (Average of WL)

18. Salinity (PPT)
0
2
4
6
8
12
10
Jan/2005
Jan/2005
Mar/2005
Apr/2005
May/2005
May/2005
Jun/2005
Jul/2005
Aug/2005
Sep/2005
Noapara Ghat
Oct/2005
Nov/2005
Dec/2005
Jan/2006
Feb/2006
Mar/2006
Apr/2006
May/2006
Jun/2006
Fultola Ghat
Jul/2006
Aug/2006
Sep/2006
Oct/2006
Nov/2006
Dec/2006
Jan/2007
Feb/2007
Mar/2007
Apr/2007
May/2007
Charerhat Ghat
Jun/2007
Jul/2007
Aug/2007
Sep/2007
Oct/2007
Nov/2007
Dec/2007
Jan/2008
Feb/2008
Rupsha Ghat
Mar/2008
Apr/2008
May/2008
Jun/2008
Jul/2008
Aug/2008
Sep/2008
Oct/2008
Salinity Trend in the Region
Mollarhat
Nov/2008
Dec/2008
Jan/2009
Feb/2009
Monthly Salinity Monitoring
Mar/2009
Apr/2009
May/2009
Jun/2009
Jul/2009
Aug/2009
Sep/2009
(Data Source: Department of Environment, DOE)
Oct/2009

19. Impact of SLR: Intrusion of 5ppt Salinity line
Dry Season
`
0 SLR
60 cm SLR
120 cm SLR
Impact of Sea Level Rise: Intrusion of 5ppt Salinity line
(compared to present scenario)
Sea Level Rise Affected area (ha) Affected Population
(SLR) due to SLR due to SLR
60cm 512,590 4,613,306
120cm 1,061,016 9,549,144

20. Population growth
140
120
• One of the densely 100
populated country 80
60
• Projected population 40
20
0
o 2025: 180million
o 2050: 220 million Rural Urban
Cropped area
• Urban: 25 million (2001), 80 Population growth
million (2025) & 140 million
(2050)
• Reduction of agricultural
land 1% annually

21. Projected Coastal population (in million)
57.9
53.6
49.0
46.6
44.2
41.8
35.1
2001 2015 2020 2025 2030 2040 2050