Presentation by Zahirul Haque Khan, Division Director Institute of Water Modelling, Bangladesh, at the Symposium Knowledge and Innovation for Decision Making, during Delft Software Days - Edition 2017. Friday, 27 October 2017, Delft.

1. Bangladesh Delta Plan 2100: Prediction of
Morphological Evolution of Meghna Estuary, and
Metamodel for decision support
Zahir-ul Haque Khan, Director,IWM
Willem Van Deursen, Deltares

2. Bangladesh Delta
 Built on the confluence of 3 mighty
Rivers- the Ganges, the Brahmaputra
and the Meghna;
 Largest dynamic delta of the world
 Around 405 Rivers: 57 Trans-boundary
(54 with India and 3 with Myanmar);
 93% catchment area lies outside
Bangladesh with annual sediment load
of 1.0 to 1.4 billion tons;
 Abundance of water in wet season but
scarcity of water in dry season.
 Bangladesh is one of the most
vulnerable country to accelerated sea
level rise (SLR)
 SLR can cause changes in morphology,
water availability and flooding 2

3. Bangladesh Delta Plan 2100
 It is a long-term, holistic, integrated and scenario
based plan
3

4. Delta Opportunities
Highly fertile land -
• Agricultural land: 65%
• Forest lands: 17%
• Urban areas: 8%
• Water and wetlands: 10%.
Plentiful rivers (more than 400 nos.) -
• Water bodies about 4.70 million ha;
• Access to the Bay of Bengal up to 1.125 million sq. km.
Open access to sea is a huge advantage -
• It could serve the needs of growing internal trade and
commerce;
• Could become a regional hub for international sea
transportation.
Inland Water Transport (around 6000 km) -
• Easiest, environment friendly and cheapest mode of
transportation;
• Almost all districts are connected with each other;
• The Industrial/Growth centers nearby rivers.
The Sundarbans -
• The largest natural mangrove forest;
• Unique ecosystem covers an area of 577,000 ha of
which 401,600 ha land and remaining 175,400 ha is
under water.
Unique ecological settings –
• There are 2 Ramsar sites, 9 Ecological Critically Areas, 17
National Parks, 20 Wildlife Sanctuaries, 8 Eco-parks and 2
Botanical Gardens.
• Important five ECAs are as below:
 Hakaluki Haor (18,382 ha),
 Tanguar Haor (9727 ha),
 Sonadia Island (4,916 ha),
 St Martin’s Island (590 ha),
 Teknaf Peninsula (10,465 ha);
• Over 800 species of wildlife identified in ECAs.
4

5. Delta Challenges
Bangladesh Delta have many challenges:
 Rising Temperatures
 Changing Rainfall
 Increased Flooding
 Droughts
 River Erosion
 Sea level rise (SLR) and consequent Salinity Intrusion
 Cyclones and Storm Surges
 Water Logging
 Sedimentation
 Trans-boundary Challenges.
5

6. 1. Baseline Analysis: Challenges and Opportunities (24 Baseline Studies: Annex-1)
The studies are related to :
• Climate Change, Natural Resources, Environment and Ecology;
• Investment and Finance, Governance, Knowledge etc.
2. Setting the Vision and Goals
3. Scenario Development
• Various plausible future scenarios based environmental, socio-economic and policy factors
• Scenario based strategy development
4. Strategy Development based on ADM Principle
• Sectoral strategies (for Water Resources, Land, Agriculture, IWT, Urban and Rural water Supply
and Sanitation)
• National Strategies (for Flood Risk Management, Fresh water etc.)
5. Investment Plan
• Macro-requirements: Hotspot wise, Cross cutting
• Project Prioritization Criteria
• Financing Arrangements and Mechanisms.
6. Implementation Framework
• Delta Commission and Delta Fund
• RBM&E Framework
• Knowledge Management.
Bangladesh Delta Plan 2100: Approaches
6

7. Six (6) Hotspot areas have been identified :
1. Coastal Zone
2. Barind and Drought Prone Areas
3. Haor and Flash Flood Areas
4. Chittagong Hill Tracts and Coast
5. Major Rivers and Adjoining Areas
6. Urban Areas
The remaining area is identified as Cross-cutting areas
characterized by a combination of issues and
challenges e.g. floods, drought, river bank erosion,
sedimentation, groundwater depletion, water
pollution and water supply and sanitation issues.
Hotspots: Planning Units of BDP 2100
7

8. Delta Vision & Goals
Delta Vision:
Ensure long term water and food security, economic growth and environmental sustainability; while effectively coping
with natural disasters, Climate Change and other delta issues through robust, adaptive and integrated strategies, and
equitable water governance.
Higher Level Goals:
Goal 1: Eliminate Extreme Poverty by 2030
Goal 2: Achieve Upper Middle Income Country (UMIC) status by 2030
Delta Plan Goals:
Goal 1: Ensure safety from floods and climate change related disasters
Goal 2: Ensure water security and efficiency of water usages
Goal 3: Ensure sustainable and integrated river systems and estuaries management
Goal 4: Conserve and preserve wetlands and ecosystems and promote their wise use
Goal 5: Develop effective institutions and equitable governance for in country and trans-boundary WR management
Goal 6:Achieve optimal use of land and water resources
8

9. Paradigm Shift to Adaptive Delta Management
As per the ADM methods- analytical framework, plausible scenarios, strategies and adaptive pathways have
been developed for 50 to 100 years mainly considering various uncertainties including climate change. In line
with those, interventions have been proposed mainly up to 2030 and in some cases up to 2040. Thus,
interventions have been proposed based on back casting analysis.
Note: Back casting is a planning method that starts with defining a desirable future and then works backwards to
identify policies and programs that will connect the future to the present.
9

10. 10
Delta Scenarios

11. Framework for Strategy Development
Strategies are developed (at national and hotspot scales) for:
• Water Resources,
• Land Resources,
• Agriculture,
• IWT,
• Urban and Rural WASH.
Preferred Strategy (national / hotspot)
High level strategy to realise the Delta Goals
Sub-strategies
Theme specific strategies
Projects
Set of short and mid-
term actions are needed
to realise sub-strategy
Hierarchy of preferred strategy, sub-strategies and
projects
Time Frame of BDP Strategy 11

12.  A ‘Delta Act’ is needed to be enacted for providing a sound legal coverage for the
long-term nature of BDP 2100 including establishment of the Delta Commission and
Delta Fund.
• GOB has a plan to allocate about 2% of GDP per annum to the Delta Fund gradually –
as indicated in the 7th Five Year Plan. At present, this amount is around US$ 4.0 billion
annually (10-12% of the Annual Budget and about 30% of ADP).
Reform of Governance and Institutions for ADM: Bangladesh Delta Fund
12

13. Bangla-Dutch Research Initiative on Flood Risk
Management and Morphological Assessment
Prediction of Morphological Evolution of the
Meghna Estuary
• Prof. Dr. Monowar Hossain
• Mr. Zahir-ul-Haque Khan, MSc
• Mr. Rubayat Alam, MSc
• Prof. Dr. Dano Roelvink
• Dr. Ali Dastgheib
• Mr. Johan Reyns, MSc
IWM UNESCO-IHE

14. Prediction of river and coastal morphology; planning of river training,
infrastructure development, river dredging and disaster management etc.
Sedimentation: Loss of navigability, water -loggingRiver erosion: loss of productive land;

15. The project consists of the following theme:
• Morphological assessment of the Meghna Estuary consequent
to sea-level rise
The specific objective is:
• To study the morphological changes in the Meghna estuary
due to sea-level rise consequent to climate change
Project Theme and Objective

16. Advanced modelling tools
MIKE21 FM
• Flexible mesh model
• Easy to generate grid for complex
areas
• So far only used for short-term
sedimentation and erosion
• Proprietary software
Delft3D 4 Suite
• Curvilinear grid
• More difficult to represent
network of channels
• Extensive experience in long-term
morphology modelling
• Free, open-source software
Combining strengths of both institutes and model systems

17. Study
Area
Chandpur

18. Bathymetry and Mesh
Developed bathymetry in MIKE21 FM model

19. Bathymetry and Mesh
Grid developed in Delft3D 4 Suite using two domain
Bhairab Bazar
Baruria
Bay of Bengal
16o Latitude Line
India
Myanmar

20. Model setup
• MIKE21 FM:
• full timeseries, run over 10 years
• only mud
• Delft3D 4 Suite:
• schematized tidal boundaries and river discharge hydrograph
• morphological speedup
• sand and mud combined

21. Calibration and Validation of the Model
Developed bathymetry in MIKE21 FM model Ramgati
Tajimuddin

22. Long Term Simulation by Delft3D 4 Suite
• Water Level data of 1982-2012 at Baruria and 1985-2009 for
Bhairab bazar were collected
• Discharge time series data were generated using rating curves
• Finally, boundaries were generated using input reduction
technique
Baruria [m]
Jan
2000
Feb
2000
Mar
2000
Apr
2000
May
2000
Jun
2000
Jul
2000
Aug
2000
Sep
2000
Oct
2000
Nov
2000
Dec
2000
Jan
2001
Date and Time
0
20000
40000
60000
80000
100000
120000
140000
160000
Discharge(cumec)
Generated Boundary for Long Term Morphology
Generated BoundaryDischarge from Rating Curve

23. 10-year simulation, present situation
Delft3D 4 Suite, overall pattern
Erosion (blue) and
sedimentation (red)
Huge
sedimentation,
flood plains not
taken into
account

24. Erosion (blue) and
sedimentation (red)
10-year simulation, present situation
detail at mouth of Meghna
Sandwip
Urir
Jahazer
Hatiya
Monpura
Bhola

25. Effect of
sea
level
rise
More
sedimentation
closer to coast
and upstream
Less
sedimentation /
more erosion
closer to coast
and upstream

26. Possible development in 50 years
Initial Final

27. Outlook
• In near future, we will be able to use such models to predict:
• Expected natural development and land reclamation potential
• Effect of sea level rise and upstream flow conditions
• Effects of polderization and changing management techniques

28. THANK YOU