G4 Presentation_Reflection Workshop_April 10-11_2013

7/28/2019 G4 Presentation_Reflection Workshop_April 10-11_2013

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Ganges Basin Development Challenge

Activities, Outputs and Future Plan


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OutcomeLogic

Model

OUTCOMES

Change in KAS Change in Practice/

behaviorImpact

Ministries of water

resources,

environment &

forests, agriculture

and fisheries inBangladesh

Scaling up

Understanding of the

effects of external

drivers & anticipated

change of water

resources and the

benefits of adaptationmeasures will

encourage these

policymakers to be

motivated to formulate

new policies. It will

also enable them for

advocacy to the

development partners.

Project outputs

Existing condition:

Detailed map of polders

& land type,

Data, Freshwater &

salinity zoning map

Water-logging map

inside the polders

Digital Elevation Model

Use of data, information &

knowledge

Understanding external drivers,

scenarios and their effects

Use of data &

information

Development of

new database

Future condition:

Population projection

Land use change

Detailed map of polders

& land type,

Data, Freshwater &

salinity zoning map

Water-logging map

inside the polders

Improved water

infrastructure plan of thethree polders

Improved andresilient water

infrastructure

and operation

Improved

Polder

management

for maximizing

crop & fishproduction and

minimizing

inundation risk

due to flood in

collaboration

with other Gs

Researchers of G1, G2, G3 & other ongoing projects

Acquiring new

information & knowledge

Understanding the

benefits of using new

information and improved

plan for proper drainage

and irrigation

Improved planning,

design and

implementation of water

infrastructure

LGI, BWDB, WARPO, LGED and NGOs

Understanding of effects of

external drivers

Motivated and encouraged

to use the new information

Assimilation of new

knowledge and

information in project

planning and approval

Ministry of Water Resources, C.C. Cell, Planning

Commission

Farmers and fishers of polder 3, 30 and 43/2F

Awareness building

Knowledge enhancement

Encouraged to

participate in discussions

External drivers

Scenarios

OutcomeLogic Model


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Overall Methodology

G4: Assessment of the impact of anticipated external drivers of change on water resources of the

coastal zone

Defining Study Area

Water Flow and Salinity Modelling

Model Development

Calibration Validation

Field Survey

and Data CollectionLiterature Review

Selection of Scenarios

Involving Gs and Stakeholders

Selection of Drivers of Change

Involving Gs and other Stakeholders

Simulation of Scenarios

Simulation of

Baseline Condition

Improved drainage and storage plan

Up-scaling to

LGED, WARPO, BWDB, DoE, Climate Change Cell

Involving G5


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External Drivers


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Final List of Key External Drivers and

Their Ranking

External Drivers and Future Scenarios

Scenario Generation Workshop

Combination

Scenarios


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Scenarios

Ganges Basin

Trans-boundary flow (best case

scenario: maximum flow since GWT)

Population growth: water extraction

from the river system

Climate change: A1B condition

(Precipitation, Temperature and Sea

level rise)

Scenario 1: 2030

Land-use change


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Scenarios

Ganges Basin

Trans-boundary flow (worst case

scenario: minimum flow since GWT)





level rise)

Scenario 2: 2030

Land-use change


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Scenario

Ganges Basin

Land-use change


scenario: maximum flow since GWT





level rise)

Scenario 3: 2030

Change in water

management practices

Change in water governance and institutions

(including policy change)

Water infrastructure development

(khal system/structure improvement,

Ganges Barrage)


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Scenario

Ganges Basin


scenario: maximum flow since GWT

Land-use change

Climate change: A1B and A2 condition


level rise)

Scenario 4: 2030 and 2050

Mimimum TBF

Maximum TBF


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Salinity Zoning Map


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Salinity Zoning Map


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Simulation of Scenarios and Effect of

External DriversFarhana Akhter Kamal


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POLDER-3


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POLDER-30


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POLDER-43/2f


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Methodology

Salinity Modelling

South-West Regional Salinity Model


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Salinity boundary

Measured Q

Sal 0 ppt

1 Dimensional Model

South-West Regional Model

salinity is zero at upstreamDownstream salinity is taken

from calibrated BoB model

2 Dimensional Model (Bay of Bengal Model)

Measured salinity at upstream boundaries

Sea Salinity = 30 to 35 ppt

Sal

Salinity = 32 ppt

Sal

SalSal

Measured Q

Sal 0 ppt

Measured Q

Sal 0 ppt

WL, Salinity in 12 downstream

boundaries

Boundary Generation


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Salinity intrusion and water availability in Base Condition

December 2011


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January 2012



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February 2012



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March 2012



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April 2012


`


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May 2012



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June 2012



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Sea Level Rise in Southwest Region

Projection of SLR from 1990-2100,basedon IPCC temperature projections for

three different emission

scenarios(Rahmstrof,2009)

Temperature ranges and associated sea-level ranges by the year 2100 for IPCC emissionscenarios

Relative Mean Sea Level (RMSL) = Global SLR + Local Effect

Rahmstorf (2009) prediction forGlobal SLR is 124cm, A1B in 2100

over 1990 water level

Local effect (from past studies

and WL trend analysis) is about

5mm/yr

Considering Global and local

effects the SLR is 22cm in 2030

and 52cm in 2050 above 2011-

2012 WL

T b d fl


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Trans-boundary flow

0

500

1000

1500

2000

2500

1960 1970 1980 1990 2000 2010

AnnualDaily Minimum Flow (m3/s)

Hardinge Bridge (Ganges River)

Daily minimum flow in the Ganges at Hardinge Bridge:

Average was 1920m3/s in Pre-Farakka period

Decreased to less than 500m3/s during Post-Farakka

The mean Increased to 730m3/s after the Ganges Water Treaty

Hardinge bridge in dry season

T b d fl


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Trans-boundary flow

Monthly maximum and minimum flow since 1998


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Upstream Boundaries (Q, Sal = 0pt)

Minimum and maximum flow in Gorai in dredged condition

Downstream Boundaries (WL, Sal) + Sea Level Rise

Evaporation (based on

temperature change)

Rainfall + R

Incorporating Drivers

(Transboundary flow +

Climate change (change in

temperature and precipitation) +Sea Level Rise


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Effect of External Drivers on Drainage Conditions

(Md Nasim Al Azad Khan)

Cross section Survey


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Cross-section Survey

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

10.0 20.0 30.0 40.0 50.0

Level(mPW

D)

Distance (m)

Cross-section of Bazar Khal

-0.5

0

0.5

1

1.5

2

2.5

3

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Level(mPWD)

Distance (m)

Cross-section of Moradaha Khal

Kazibacha river


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Level (mPWD) Area below %

0.60 15

1.00 611.20 80

1.60 95

1.80 98

2.00 99

Digital Elevation Model

Average water level 1.3 m

Average water level 1.0 m

Lower-Shalta river

0 20 40 60 80 100

0

0.5

1

1.5

2

2.5

3

3.5

4

0 10 20 30 40 50 60

Area (Percent)

Landlevel(mPWD)

Area (sqkm)

Area-Elevation curve

l d k f


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Internal Road Network of

Polder-30

Existing drainage system of Polder-30

78 Khals

15 Drainage Regulator (5 nos. 2-

vent, 10 nos. 1-vent)

D li ti f t h t f i t l


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Delineation of catchments for internal

khal network using Digital Elevation

model, Road networks and Khals

Total 54 no. of Catchments


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Rainfall Water level hydrograph at Khals

Water depth hydrograph at flood plain


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Average Flood Event

1 day inundation depth

Flood type Area (sqkm) Area (%)

Flood free 30.20 47

F0 (0 - 30 cm) 23.62 37F1 (30 - 90 cm) 9.46 15

F2 (90 - 180 cm) 1.24 2


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Average Flood Event



Flood free 54.85 85

F0 (0 - 30 cm) 4.45 7F1 (30 - 90 cm) 5.20 8


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Average Flood Event



Flood free 58.58 91

F0 (0 - 30 cm) 4.57 7F1 (30 - 90 cm) 1.36 2


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25 Year Flood Event


Flood type Area (sqkm) % of Area

Flood Free 10.44 16

F0 (0 - 30 cm) 15.01 23F1 (30 - 90 cm) 30.90 48

F2 (90 - 180 cm) 7.895 12


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25 Year Flood Event



Flood Free 25.48 40

F0 (0 - 30 cm) 21.01 33F1 (30 - 90 cm) 13.42 21

F2 (90 - 180 cm) 4.32 7


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25 Year Flood Event



Flood Free 45.55 71

F0 (0 - 30 cm) 9.81 15F1 (30 - 90 cm) 8.57 13

Ganges, Brammaputra and Meghna Basin


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Ganges, Brammaputra and Meghna Basin

Meghna Basin

82,000 sq.km

Brahmaputra Basin

552,000 sq.km

Ganges Basin

1,087,000 sq.km

B A Y O F B E N G A L

BHUTAN

I N D I A

C H I N A

BANGLADESH

I N D I A

Bangladesh rivers receive runoff from a catchment

of 1.72 million sq. km, around 12 times its land area

Upstream Boundaries: Flows in climate change scenario


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Downstream Boundaries: Sea Level Rise

Evaporation (based ontemperature change)

Rainfall +

Precipitation at Polder Rainfall + R

Evaporation (based on

temperature change)


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25 Year Flood Event (Scenario_2030)



Flood Free 9.18 14

F0 (0 - 30 cm) 12.00 19F1 (30 - 90 cm) 33.61 52

F2 (90 - 180 cm) 9.72 15


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Flood Free 21.97 34

F0 (0 - 30 cm) 22.24 34F1 (30 - 90 cm) 15.26 24

F2 (90 - 180 cm) 5.03 8


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Flood Free 41.71 65

F0 (0 - 30 cm) 13.01 20F1 (30 - 90 cm) 9.15 14

F2 (90 - 180 cm) 0.64 1


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Drainage improvement plan


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Improvement Plan-1

Re-excavation of

Jhapjhapia river and

khals of most water

logged areas in thewestern part of the

Polder


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Improvement Plan-2

Re-excavation of

Jhapjhapia river and

khals of most water

logged areas in thewestern part of the

Polder + Additional

regulating structure

Upgrading the Milemara

regulator from 1-vent to 2-vent

One 2-vent Regulator at

Tegodanga khal



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With improvement plan-1


3 day inundation depthWith improvement plan-2

Flood type Present condition Plan-1 Plan-2Area (sqkm) % of Area Area (sqkm) Area (%) Area (sqkm) Area (%)

Flood free 22 34 35 54 42 65

F0 (0 - 30 cm) 22 34 20 31 16 25

F1 (30 - 90 cm) 15 24 9 14 6 10

F2 (90 - 180 cm) 5 8 1 1 0 0


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Population and Land use Projections

(Dr. Muthuwatta Lal, IWMI)


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Lal Muthuwatta, Aditya Sood, Upali Amarasinghe and Bharat Sharma

(IWMI)

SWAT modeling for Ganges River Basin


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Introduction

The aim of the study is to quantify the impacts of various

external drivers on the stream flow of Ganges. To accomplish

this, a hydrological model is developed to simulate stream flow

at various locations in the Ganga River Basin, This model will

then be used to analyze the impacts of anticipated external

drivers on stream flow of the GRB.


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Specific objectives

Collect and document baseline data to develop a

hydrological model for the Ganges River Basin.

Develop a hydrological model of the Ganga River Basin to

simulate stream flow.

Asses the hydrologic implications of various future

scenarios.

D t


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Data

Number of precipitation stations 784 ( 1979 2010)

Number of temperature stations - 784

Number of stations for solar radiation, wind speed and humidity - 266

Land use ( Satellite based classified map)

Soil data ( FAO soil map)

DEM ( SRTM)

Climatic data is collected from different sources such as IWMI water data portal, IMD gridded

data and Bdesh met. Department, re-analysis data.


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SWAT Sub-basins G4

Number of sub-basins - 1685

Average size 527 km2

Ob Si t th H di B id


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Obs. vs. Sim. at the Harding Bridge.

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

Jan-81

Sep-81

May-82

Jan-83

Sep-83

May-84

Jan-85

Sep-85

May-86

Jan-87

Sep-87

May-88

Jan-89

Sep-89

May-90

Jan-91

Sep-91

May-92

Jan-93

Sep-93

May-94

Jan-95

Sep-95

May-96

Jan-97

Sep-97

May-98

Jan-99

Sep-99

Flow(m3s-1)

Month

Simulated Observed

Cal ( 1981-1990) Val (1991-2000)

NS 0.7 0.75

R2 0.73 0.81


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Water yield (mm/year)


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Annual water balance components

0

200

400600

800

1000

1200

1400

1600

1800

2000

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

mm

Year

Precipitation ETa Water yie ldWB Terms mm/year

Surface runoff 483.3GW recharge ( Shallow) 254.6

Deep Aq. Recharge 13.8

Actual ET 385.8

Rainfall - 609 to 1796 mm/y

Water yield - 250 to 1300 mm/y

Population projections and domestic


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Population projections and domestic

water demand

Domestic water demand of the part of Ganges river basin in

Bangladesh for the years 2030 and, 2050.

Data from population census in 1991, 2001 and 2011 at Zila

level

Population projections for 2030 and 2050 by UN


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Population - 2001

d


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Procedure

-1 Growth rate

,20+ 20+ ,200+0,20+ 20+ ,200+0 ,200+0

C is chosen as:

20+ ,20+ ,20 1 ,20+

=

=

20+ and ,200+0 the annual population growth of the countryand the ith sub-national unit after 2011


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Rural and urban population (1000s)

Sub-

basin

Population 2001 Population 2011 Population 2030 Population 2050

Urban Rural Urban Rural Urban Rural Urban Rural

1 349 1786 427 1947 441 2013 441 2013

2 874 3305 897 3672 916 3757 916 3758

3 548 3259 592 3589 608 3701 608 3702

4 821 1735 560 2044 561 2057 561 2057

5 194 956 204 964 204 964 204 964

6 134 509 113 548 113 551 113 551

7 207 1491 241 1581 254 1669 254 1670

8 179 1265 190 1288 435 3048 435 3049

9 73 633 119 612 169 971 169 971

10 59 641 160 596 160 596 160 596

11 80 506 101 470 115 480 115 480

12 118 1329 300 1277 302 1292 302 1292

13 131 878 153 577 323 707 323 707

14 127 1015 155 682 366 845 366 845

15 145 1185 180 1164 197 1289 197 1289

Total 4037 20494 4392 21011 5166 23940 5167 23944

Urban Rural2001-2011 8.8% 2.5%

2011-2030 17.6% 13.9%

2030-2050 0.02% 0.02%

Water demand by the population in different sub basins (million cubic


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Water demand by the population in different sub-basins (million cubic

meters)

Sub-

basin

Water demand

2001

Water demand

2011

Water demand

2030

Water demand

2050

Urban Rural Urban Rural Urban Rural Urban Rural1 19 54 23 59 24 61 24 61

2 48 100 49 111 50 114 50 114

3 30 99 32 109 33 112 33 112

4 45 53 31 62 31 62 31 62

5 11 29 11 29 11 29 11 29

6 7 15 6 17 6 17 6 17

7 11 45 13 48 14 51 14 51

8 10 38 10 39 24 92 24 92

9 4 19 7 19 9 29 9 29

10 3 19 9 18 9 18 9 18

11 4 15 6 14 6 15 6 15

12 6 40 16 39 17 39 17 39

13 7 27 8 17 18 21 18 21

14 7 31 8 21 20 26 20 26

15 8 36 10 35 11 39 11 39

Total 221 621 240 637 283 725 283 725

Rural 83 lpd

Urban 150 lpd

The domestic water demand in the Ganges Basin of Bangladesh is projected

to increase by roughly 15% till 2030 and will then stabilize.


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Refrences

Al-Amin M., Mahmud, K., Hosen H., Islam M.A. (2011). Domestic water

consumption patterns in a village in Bangladesh. 4th Annual Paper Meet and

1st Civil Engineering Congress, December 22-24, 2011, Dhaka, Bangladesh

ISBN: 978-984-33-4363-5 Noor, Amin, Bhuiyan, Chowdhury and Kakoli (eds).

Ganges barrage study project, Feasibility report, 2012.


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Projecting Land Cover of Bangladesh

Uses the aggregated statistics in a first order MarkovChain model to project future LC.

First order Markov Chain treats that LC classesbehavior as a stochastic variable (Y), and that thestate in the current time period depends onlyon the states, , j=1,..,J, of the previous timeperiod.


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Procedure

probabilistic terms this can be expressed as

/

=

P ( ) and P ( ) are probabilities that Y is in state i in tth time period,and state j in (t-1)st time period.

P (Yt(i)| Yt-1(j))= Pij is the conditional probability that Y is in state i in tth time

period given that Y is in state j in (t-1)th time period.


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Transition probability matrix

2 . . 2 22 2.

..

.2 . . .

.

.

Pij Transition probability from state j to i from (t-1) to tth time period.

Transition Probability Matrix for LULC of


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Bangladesh

LULC Forest Fallow

lands

Waste

lands

Not available

for agriculture

Single

cropped

Double

cropped

Triple

cropped

Forest0.74 0.00 0.00 0.00 0.02 0.24 0.00

Fallow lands0.00 0.64 0.06 0.13 0.13 0.00 0.06

Waste lands0.00 0.00 0.60 0.40 0.00 0.00 0.00

Not available for

agriculture0.05 0.00 0.03 0.72 0.10 0.04 0.06

Single cropped0.00 0.07 0.00 0.00 0.83 0.11 0.00

Double cropped 0.10 0.00 0.00 0.20 0.00 0.58 0.12

Triple cropped0.00 0.00 0.00 0.00 0.00 0.72 0.28

Steady state

probabilities0.15 0.03 0.03 0.26 0.19 027 0.07

2010

2002


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Next step..

To run the scenarios of climate change, population increase

and land use change. Climate change will have impact on

both the spatial and temporal distribution of the rainfall.

Increasing population will lead to increasing demand of

water abstraction from the basin. It will also lead to landuse

change. The influence of such changes on the water yield

and flow of the river will be quantified.

Work Plan 2013


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Work Plan 2013

List of Working Papers Spatial and temporal variation of water flow and salinity in the coastal

zone of the Ganges delta Downscaling of GCM and climate change projections

Identification and prioritization of external drivers of change

Future scenarios of external drivers of change

Water flow, drainage and salinity modelling techniques

Projection on Population growth and water requirement in 2030 and 2050

Projection on land use in the coastal zone of Ganges in Bangladesh

Effects of external drivers on water resources and salinity intrusion

Implication of adaptation measures on drainage

Projection on land-use change and assessment of water requirement forthe Coastal Zone of Ganges in Bangladesh

Atlas of Salinity zoning map

Atlas of inundation depth map

Work Plan 2013


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No. Activity- Milestone ExpectedCompletion Date

0 Project Implementation 30/03/2014

1 Field visits, interaction meetings, data collection,

literature review, driver identification, workshop

31/12/2013

2 Assessment of climate scenarios and projections Completed3 Assessment of cross-boundary flow, effect of land-use

change and population growth

30/04/2013

4 Simulation of scenarios and assessment of anticipated

changes on water resources

30/06/2013

5 Simulation of scenarios and assessment of anticipated

changes for the selected polders (3, 31 & 43-2F)

30/06/2013

Future Research Questions


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1. Assessment of water quality and availability in the drainage channel over

the year in the coastal polders

2. Improved operation rules for drainage and irrigation management ofpolders involving local community

3. Establishment of sea level rise along the coast of Bangladesh for different

emission scenarios considering local and global effects

4. Dynamic downscaling of GCMs for better climate change projections forhigh emission scenarios in the coastal polders

5. Assessment of future sedimentation and drainage condition in the

peripheral rivers and adaptation strategies for better drainage management

of polders

6. Long term monitoring of sea level rise and salinity in the coastal area

7. Modelling of change of water management practices

8. Improved planning of gravity irrigation system at low saline zone

9. Planning Sarjan system in the low lying coastal area for climate resilienta uaculture and a riculture at communit level


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THANK YOU

Documents

G4 Presentation_Reflection Workshop_April 10-11_2013