farhana ahmed "learning from our futures"
TRANSCRIPT
Communities and Institutions for Flood ResilienceTurning Tides?
Learning from our futures Resilient Adaptation to Flood Risks under
Urban Growth and Climate Change Dynamics
Promovendus: Farhana AhmedPromotor: Prof. Chris ZevenbergenSupervisors: Berry Gersonius, William Verbeek
2 November, 2012
Research Background• Cities are prone to hazards with 233 out of 633
cities or urban agglomerations and 663 million inhabitants vulnerable to high risk of flooding
• World urban population is presently more than 50%, expected to reach 67% by 2050
• Of which, 86% population in the more developed regions and 64% in the less developed regions.
• Urbanization rate of 1.32% in less developed regions, is more than developed region with 0.4%
• Climate change will increase precipitation and more frequent flooding events.
Physical effects– Damage to structures and – Infrastructure
Environmental effects– Water quality through
contamination of drinking water and water bodies
– Public health issues and – Aesthetic influence
Socio-economic effects– Economy– Societal disruption
Adverse Effects of Flood
• Within 1995-2004, flood contributed to 20% death toll
• 33% economic losses
Project Background
Partners: Dutch institutes (Wageningen University, UNESCO-IHE) &Bangladeshi Institutes (IWFM-BUET, CEGIS)
Analyze the strategies and policies of rural, urban, epistemic and policy communities to reduce flood risks and vulnerabilities
Period: 2012-2016
Communities and institutions for flood resilience: enhancing knowledge and capacity to manage flood risk in the Bangladeshi and Dutch Deltas
Integration among the PhDs under WOTRO
PhD-1:Dealing with uncertainty: the delta knowledge agendas in the Netherlands and Bangladesh
PhD-3: Rural climate-change adaptation in Bangladesh: strengthening flood resilient communities
PhD-4: Linking climate change adaptation and disaster risk reduction with floods: towards resilient deltas
PhD-2: Assessment of rigid vs flexible flood adaptation and mitigation sStrategies under dynamic urban environment and changing climate
Urban-Rural Flood Management Practices in BD
Delta lessons and Water Management Practices in the Dutch-BD deltas
Adaptation and Mitigation Strategies in BD-Netherlands
Publications(Journals/Book)
Workshops/seminars
PhD Thesis
Integration process among the PhDs
Dissemination
Publication and Dissemination
Website
Flood Risk Assessment and Adaptation Approaches
• Qualitative vs Quantitative assessment
• Resilience (Socio-technical) approach vs robust engineering approach for Flood Risk Mitigation and Management
• Different Approaches: Adaptive Policy Making (APM), Adaptation Tipping Point (ATP), Real-In-Options (RIO), and Adaptation Tipping Point - Adaptation Mainstreaming Opportunity (ATP-AMO)
ATP’s in water management are the specific boundary
conditions where technical, economic, spatial or societal
acceptable limits are exceeded.
Top-down
Bottom-up
Static
Dynamic
Caused-based/impact
Effect-based/ vulnerability
RIOATP, Exploratory
Modelling
Decision Analysis Adaptation Pathways
ATP-AMO
Risk ManagementAPM
AdaptationPolicy
Pathways
Adaptation
Gaps in the State of the Art
• Uncertainty in urban growth scenario (Planned and unplanned)
• Uncertainty in climate change / flood predictions• Lack of adequate/accurate data• Constraints for adaption (financial constraint, large-scale
in-migration, gap in technical knowhow)
Objectivesto identify the impacts of changing climate and urbanization on urban flooding and to assess the effectiveness of management, including flood mitigation and adaptation. The specific objectives are:
I. Tailor the adaptation tipping point (ATP) method to a constrained context such as experienced in developing countries.
II. Extend the traditional application of the ATP method through the incorporation of multiple drivers, namely climate change and urban growth.
III. Demonstrate the extended ATP method for the current flood risk management (FRM) strategy for Dhaka.
IV. Develop alternative FRM strategies including multi-layer safety for Dhaka by taking a combined top-down/bottom-up approach, and assess these strategies with the extended ATP method.
V. Compare the effectiveness of multi-layer safety for adapting to increasing flood risks between Bangladesh and the Netherlands.
Research questionsI. How can the ATP method be adapted to a developing country
context, in which management objectives may be lacking, not well defined or exceeded?
II. How can the spatio-temporal dynamics of (planned and unplanned) urban growth be incorporated into the ATP method?
III. What are the (intermediate) goals, measures and critical ATPs of the current FRM strategy of Dhaka?
IV. Which alternative FRM strategies can be identified for Dhaka, and are these strategies effective in postponing the critical ATPs?
V. Is multi-layer safety an effective way to adapt to changes in flood risk in urbanised delta areas?
DhaleswariRiver
Tongi Canal
BurigangaRiver
Turag river
BaluRiver
LakhyaRiver
Dhaka City-The Case Study• Area of DMA is 360 sq.km and DAP area is
1528 sq.km (590 sq mile)
• Population of Dhaka city: 12 million (2010)
• DWASA: key agency for water supply system, sewerage and drainage (since 1963)
• Present water demand: 2200 MLD
• Water demand: 91% demand is met up by 4 SWTPs and 575 DTWs
• Source of water: 87% water from DTWs
Five rivers: Turag, Buriganga, Dhaleshwari, Lakhya, Balu and Tongi canal
Ground water: Relatively low depth of aquifer
Rainfal: 2400 mm average annual rainfall (between 2001-2008, NWRD)
Dordrecht-The Case Study• in the delta of the rivers Rhine and Maas and is
situated in the transition area between rivers and sea.
• 118 thousand inhabitants with a population of 1500 inhabitants per km2
• 99 km2 of which 19 km2 consists of surface water.
Change in Builtup area (1993-2007) Change in Vegetation area (1993-2007)
58% to 40% 23% to 47%
Data Source: IWM
•75% area of western part inundated•Duration of 3 weeks•Flood height higher than 1998 (3-4.5m)•2.5 million people affected
Flood map of 1988
•23% area of western part inundated•61 wards were affected•Duration was 2 months
Flood map of 1998
Flood map of July-Aug 2004
•Inundated Area 40% •600 mm rainfall from 11-15th Sept•Average 297 mm•341 mm rainfall on 13th Sept
Flood map of September 2004
Flood map of August 2007
• Above average year flooding • Less severe than 2004, 1998 or 1988• Record number of patients with diarrhoea (21,401 in
August), dehydration and cholera. (Source: ICDDRB)
• Highest rainfall of 333 mm in 24 hrs between 27th-28th July. • 1 day maximum rainfall of 448mm
Flood Map of July 2009
Dhaka City Flood Management Systems
Flood InfrastructureWestern Part (136 sq km)• Fully flood protected• Inundation occurs due to
intensive rainfall• Inadequate drainage systems
Eastern Part (124 sq km)• No flood protection
• Encroachment of water bodies• Lack of coordination between
agencies
DHAKA: LOCATED IN THE DELTA FORMED BY GANGES
-BRAHMAPUTRA/JAMUNA -MEGHNA SYSTEMS
Fig. 6: Temporeal variation of the deviation of daily rainfall during July-September 1988 from the daily normal of 1961-1990
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-10
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30
40
1-Jul 11-Jul 21-Jul 31-Jul 10-Aug 20-Aug 30-Aug 9-Sep 19-Sep 29-Sep
Dates
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Fig. 7: Temporeal variation of the deviation of daily rainfall during July-September 1998 from the daily normal of 1961-1990
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1-Jul 11-Jul 21-Jul 31-Jul 10-Aug 20-Aug 30-Aug 9-Sep 19-Sep 29-Sep
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Fig. 8: Temporeal variation of the deviation of daily rainfall during July-September 2004 from the daily normal of 1961-1990
-50
0
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100
150
200
250
300
350
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1-Jul 11-Jul 21-Jul 31-Jul 10-Aug 20-Aug 30-Aug 9-Sep 19-Sep 29-Sep
Dates
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m)
Deviation of Rainfall from daily normal (1961-1990)
Hydrographs of Buriganga at Dhaka (1988-2009)
Review of Planning InitiativesDacca Master Plan, 1958, DIT
Basically a land use plan prepared for 20yr period.
Dhaka Metropolitan Development Plan (DMDP) 1995, by RAJUK (MOHPW) DMDP includes:
a) Structure Plan (SP) 1995-2015b) Urban Area Plan (UAP)/Master Plan (1995-2005)c) Detailed Area Plan (DAP)
SP provides long term strategy for growth, spatial and sectoral policies UAP, a mid term plan, includes Resource maps, Interim management report & Multi
sectoral investment program DAP provides detailed planning for specific sub areas.
Detail Area Plan (DAP) Approved by cabinet on 21st June, 2010 Includes 3.4 lakh acres (excluding restricted areas) Provides detailed planning proposals for specific sub-areas of Dhaka Objective is to prevent flooding & ease the traffic congestion
Review of Planning InitiativesFlood Action Plan (FAP 8A and FAP 8B) Prepared in 1988 for flood protection and drainage of the Greater Dhaka City FAP-8A comprises the East area (124 km2) of Dhaka city and FAP-8B comprises of
West area (136 km2) of Dhaka city. FAP-8B program proposes construction of drainage facilities along with Natural
drainage khals/canals, Natural storage and reservoirs of storm water
BANGLADESH CLIMATE CHANGE STRATEGY & ACTION PLAN 2009 Adapt of climate change threats Contains two parts First part based on physical and climatic contexts, core socio-economic realities
and policies in the country and the consequent rationale for a strategy on climate change
Second part proposes interventions on six thematic areas: i) Food Security, Social Protection & Health, ii) Comprehensive DM, iii) Infrastructure, iv) Research & Knowledge Management, v) Mitigation & Low Carbon Dev., vi) Capacity Building & Institutional Strengthening
Some Ongoing Projects DWASA projects, funded by JICA, include khal improvement,
main drains, construction of culvert and dredging. Badda urgent project to remove water logging (DWASA) Dholai Khal Rehabilitation and area development (DCC/World
Bank) Detail design of FAP 8B, funded by ADB which includes
strengthening of the western embankment with pumps and sluice gates.
Bangladesh Delta Plan Preparatory phase CORFU project
Bangladesh Delta Plan draws experience from the
"Netherlands Delta Plan 2100“ will be incorporated in the sector plans will be implemented through dev.
programmes of GOs and NGOs appropriate institutional arrangement funding source from govt. revenue and
development budget and development partners
a holistic long term (50 to 100 years) integrated strategy plan for Bangladesh
to achieve long term sustainable development through adaptive water governance
Future Planning Initiatives
Proposed Methodology for the study
Urban Growth Modelling
Input Process Output
Urban Growth Scenarios
Flood Risk Modelling
Rainfall River Water level
Climate change scenarios Urban Drainage System
Flood Scenarios
Landuse Demography
DEM
Adaptation Assessment
Adaptation Tipping Points
Flood Risk Management & Adaptation Strategies
Urban Development Policies & Plans
Climate Change Policy and Action Plan
Urban growth scenarios
20102015202020252030203520402045205020552060
Flooding under different UG scenarios
Conclusion/Concerns Dhaka is in its incumbent stage of implementation of the DAP Urban growth’s threshold value have to identified and taken
into consideration at planning/policy level Climate change effects needs to be specific and concise to be
able to help set the standards for decision making Adaptation tipping points and turning points needs to be
identified Adaptive delta management approach in perspective of
changing urban and climate environment needs to be examined
Flood management with inclusion of flexible and rigid strategies need to be compared to find the best combination