Farhana Ahmed "Learning from our futures"

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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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

Documents

Farhana Ahmed "Learning from our futures"