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Megumi MUTO Research Fellow, JICA Research Institute Muto.Megumi@jica.go.jp

June 29, 2010

JICA-WB-ADB Joint Study: Climate Risks and Adaptation in Asian Coastal Mega-Cities (The Case of Metro Manila)

Photo: BBC

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Objectives of the Research

  To inform decision makers: - The scale of climate related impacts and

vulnerabilities at the city level - Estimates of associated damage costs - Approaches to prioritize adaptation options   Through: i)  Determining climate variables at the level of the

city/watershed through downscaling ii)  Estimation of impacts and vulnerability through

hydro-meteorological modeling, scenario analysis and GIS mapping

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Bridging Science and Practice

Overall Framework

Methodology

City Case Studies

JICA 　–　 ADB　 –　 World Bank alliance

JICA – IR3S alliance

E.g. JICA: Metro Manila Coastal Engineering & Storm surge: University of Ibaraki River hydro: CTI International Transport: ALMEC Urban poor: Ateneo de Manila University Firms: National Statistics Office Health: University of Tokyo

Solutions to Operations

-  Urban planners, local governments -  Concerted donor efforts (e.g. World Bank, ADB, bilateral donors)

Coordinator and economic analysis JICA

(Manila) (HoChiMin City) (Bangkok, Kolkata)

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Flood Prone Areas in Metro Manila

West Mangahan Area

Pasig-Marikina Basin KAMANAVA Area

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Downscale IPCC climate models for temperature increase @2050 for B1 and A1FI scenarios

Assess local effects on precipitation and combine with sea level rise/ storm intensification

Simulate different types of hydraulic effects: 1) through river systems, 2) through sea level rise, and 3) through storm surge at the coast

Based on the flood maps produced for 18 cases (3 climate scenarios x 2 infrastructure scenarios x 3 return periods), estimate socio-economic impact (both direct and indirect) with available data, thus deriving the benefit side of adaptation. Consider investment mix and their costs necessary for adaptation (focusing on flood control infrastructure)

Conduct Net Present Value Calculations

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1 Downscale IPCC climate models for temperature increase @2050 for B1 and A1FI scenarios

Photo: BBC

Photo: BBC

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Global temperature projection by IPCC

Year

2020 2030 2050

Scenario A1FI 0.7K 1.0K 2.0K

B1 0.6K 0.8K 1.3K

Uncertainties in climate models

Uncertainties in the society/economy

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Local temperature change

% change of Precipitation

Future precipitation

IPCC models

IPCC models

observation

IPCC A1FI Scenario (Specified)

Overall procedure

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2 Assess local effects on precipitation and combine with sea level rise/ storm intensification

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Simulation Cases (Case of Metro Manila)

Simulation Case Temperature Rise (oC)

(downscaled)

Increase Rate of Rainfall

(%)

Sea Level Rise (cm) (global)

Storm Surge Height (m)

1 Status quo climate 0 0 0 0.91

2 B1 with storm level at status quo

1.17 9.4 19 0.91

3 B1 with strengthened storm level

1.17 9.4 19 1.00

4 A1FI with storm level at status quo

1.80 14.4 29 0.91

5 A1FI with strengthened storm level

1.80 14.4 29 1.00

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3 Simulate different types of hydraulic effects: 1) through river systems, 2) through sea level rise, and 3) through storm surge at the coast

Photo: JICA

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Upper Watershed of Metro Manila

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Source: (JICA, 2010)

Rainfall Runoff Calibration Hydrographs

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100-year Flood, A1FI under Existing Structures

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Summary of Inundation Area in the Pasig-Marikina Basin

Simulation Case

30-year Flood 100-year Flood

Existing Structures (halfway

through current Master Plan)

Continue Implementing

Current Master Plan

Existing Structures

(Halfway through current Master

Plan)

Continue Implementing

Current Master Plan

1 Status quo climate

34.6 km2 14.7 km2 53.7 km2 29.1 km2

2 B1 42.5 km2 20.8 km2 63.2 km2 40.1 km2

3 A1FI 47.0 km2 22.8 km2 68.0 km2 44.1 km2

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Bridging between research and practice is challenging

A : Flood due to insufficient drainage B : Not covered in our model due to lack of lateral profile data C : Not covered in our model as it is not overflow from Pasig-Marikina River D : Area not covered in our analysis

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4 Based on the flood maps produced for 18 cases (3 climate scenarios x 2 infrastructure scenarios x 3 return periods), estimate socio-economic impact (both direct and indirect) with available data, thus deriving the benefit side of adaptation.

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Direct Impact Assessment Flowchart

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Data from Direct Impact Indirect Impacts Analysis

Flood Affected Buildings

Flood Affected Area and Roads

Traffic Zones

Firms, residential

Income Loss of Income

Trips Generated/ Attracted (Public Mode)

Trips Generated/ Attracted (Private Mode)

Travel Time Delay Cost

Unit rate from Firm, household surveys

Time Value: Public Users “To work” &

“Business” Trips Time Value:

Private Users

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Added up benefits (savings in damages)

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Summary of Damage Costs

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Damage as % of GRDP

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5 Consider investment mix and their costs necessary for adaptation (focusing on flood control infrastructure)

Photo: The New York Times

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Adaptation Measures to Climate Change in Metro Manila

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6 Conduct Net Present Value Calculations

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NPV Analysis

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Conclusion and way forward

  1) Costs of damage will be substantial in Asian Coastal Mega-Cities

  2)Urban plans and flood protection infrastructure need to take climate risks into consideration

  3) Need to address other non-climate factors such as improved management of canals and drains

  4) Potential cross-fertilization with disaster risk reduction community