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Adaptation in Action: Options and strategies in Bangkok

Adaptation in Action: Options and strategies in Bangkok. S M Wahid Advisor, WB Bangkok CC study Asian Institute of Technology. Future climate and Bangkok. Changes in temperature. Snow and ice melt. Sea level rise. Changes in land subsidence. Changes in the Infrastructure.

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Adaptation in Action: Options and strategies in Bangkok

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  1. Adaptation in Action:Options and strategies in Bangkok S M Wahid Advisor, WB Bangkok CC study Asian Institute of Technology

  2. Future climate and Bangkok Changes in temperature Snow and ice melt Sea level rise Changes in land subsidence Changes in the Infrastructure Changes in precipitation and evapotranspiration Changes in storm surge Backwater effect of tides Changes in watershed runoff Changes in flood (depth and duration) Inhabitants Building and housing Transportation Water supply and sanitation Energy Public health Impact

  3. Climate change scenarios • Notes: • Current 2008 with existing flood protection infrastructures • Future 2050 with the planned flood protection infrastructures • Case A1 FI: temperature increases 1.9oC, precipitation increases 3%, and sea level rises 0.29 m. (from JBIC) • Case B1: temperature increases 1.2oC, precipitation increases 2%, and sea level rises 0.19 m. (from JBIC) • Strom surge: adding 0.61 m (estimated by Watana, 2005) on the crown of the maximum sea level

  4. Flood volume and peak Precipitation increase by 3% (A1FI) and 2% (B1) –  Flood volumes increase at about the same percentage  Flood peaks increase more due to the unequal travel times of flood

  5. Inundated area for 30-Year Flood In terms of flood volume, 30-year return period flood in 2008 = flood in 1995 Inundated Area in 2050 Increased from 2008 by: Land Subsidence (LS) = 3.35% Increase due to Sea Level Rise (SR)+ B1 = 27.2% Increase due to Sea Level Rise (SR)+ A1FI = 30% Increase due to Storm Surge (SS) = 1.89%

  6. Max. inundation for 30-Year Flood Eastern part - mostly protected except some areas where the crest elevations of dikes are not high enough Western part crest elevations of dikes are not high enough to protect the flood and sea level rise especially in the west and south of the area

  7. Storm surge effect into the CP river C2050-LS-SR-SS-A1FI-T30

  8. Impact assessment

  9. Additional (due to CC) 0.25 million people are from 5 districts (Lak Si, Sa Thon, Khlong San, Yannawa, Nong Chok) Flooded population An additional 0.68 million people may be living in flooded area in the future due to climate change

  10. Large daily wage earning population in condensed housing may loose income Condensed housing (>94 units/ha or >15 units/rai)

  11. 89,000 building will be flooded in Don Muang in future worst case 1.16 million buildings will be vulnerable (inundated >10cm for varying number of days; About 1/3 are in Bang Khun Thian, Bang Bon, Bang Khae and Phra Samut Chedi districts 0.9 million are residential building

  12. Mostly clinics in Bang Khun Thian, Bang Bon, Bang Khae and Phra Samut Chedi districts are affected

  13. NO electrical substation is flooded

  14. Nong Kham solid waste transfer station will be flooded with depth of 50-100 cm. in future the worst case

  15. Change* due to CC in 2050

  16. Impact types • Direct damage- measurable and often relates to the replacement value of destroyed immovable assets and stocks • occur at the time of the disaster or within a short time. • Indirect damage- not physical but can have negative effect on the economy • income loss due to temporary suspension of business or income loss because of failure to operate normal economic activities - are typical examples of indirect damage. • occur over a period of weeks after the disaster has struck, depending on the time required to achieve “normalization” of activities

  17. Assessed sectors

  18. Direct damage Direct damage = No. of affected buildings x Damage rate x Unit value of building and asset Source: Royal Irrigation Department (RID) Unit value - average book value Residential units (building) - legal right registration; Residential units (asset) - Population and Housing Census, 2000; based on 12 durable household appliances; increased by 10 per cent to account for other vulnerable assets Commercial units (building and assets) - NSO’s 2006 Business Trade and Services Survey Industrial units (building and assets) - NSO’s 2007 Industrial Census Depreciation rate - Department of Treasury

  19. Indirect damage - Population • Economic hardship of the affected population due to flood • People may not have access to their work places • Assumptions • Daily wage earners living in the condensed community (slum) would be vulnerable to the indirect impact of flooding. • People living in the condensed community has income below the poverty line of 68 baht/day/person (NESDB, 2007) • Income loss • 68 baht/day/person x number of affected condensed community (slum) dwellers x flood duration

  20. Indirect damage - commerce • Loss of income due to business suspension =No. of affected commercial establishment x Income loss/day/establishment x Flood duration • Income (value added) = 8,711 baht/day/establishment • NSO’s 2006 Business Trade and Services Survey • Assume • during business suspension due to flooding 10% of average business operating cost (3,781 baht/day) will not be incurred; SO.. • Income loss = 4,930 baht/day/establishment

  21. Indirect damage - industry • Loss of income due to industry closure during flooding • Industrial income loss = No. of affected industrial establishment x Income loss/day/establishment x Flood duration • Average value added income = 20,274 and 63,014 baht/day/industry for Bangkok and Samut Prakarn respectively • Assumption –during industrial closure 10% of average operating costs - 5,601 and 18,971 baht Bangkok and Samut Prakarn respectively - will not be paid • Income loss - 14,673 and 44,043 baht/day/industry in Bangkok and Samut Prakarn respectively.

  22. Indirect impact – water supply • Dysfunctional when the flood water rises two meters above the surrounding ground surface • Net revenue loss = No. affected household/establishment x Water supply/household x Water sales rate x Flood duration • Water supply • = 0.48 m3/day/household (residential unit) • = 3.71 m3/day/establishment (non-residential unit) • Water sales rate • = 10.00 baht/m3 (Residential unit) • = 13.75 baht/m3 (Non-residential unit) • Source - 5-year record of the Metropolitan Waterworks Authority (MWA)

  23. Indirect impact - sanitation • Wastewater treatment system and solid waste management system – operation suspended when the flood water rises two meters above the surrounding ground surface • Loss on operation = Affected population (no.) x waste generation rate x Treatment/disposal cost x Flood duration • Generation rate • Wastewater = 0.37 m3/capita/day • Solid waste = 1 kg/capita/day • Wastewater treatment cost = 12.17 baht/m3 • Solid waste disposal cost = 454.75 baht/ton • Source - Department of Drainage and Sewerage (DDS), BMA record in 2007

  24. Indirect impact – public health • Additional medical attention needed for.. • 12.5 % population (50-100 cm flood depth) • 25 % population (101-200 cm flood depth) • 37.5 % population (>200 cm flood depth) • Average health care cost (Health and Welfare Survey by National Statistical Office, 2005) = 7,582 baht/person/admission (Bangkok) = 3,786 baht/person/admission (Samut Prakarn)

  25. Indirect impact – energy sector • No direct impact to the power generation plants • relocated outside BMR in the future • No direct impact to the power substations • flood depth remains below 1 m depth which is considered by the Metropolitan Electricity Authority (MEA) • Indirect impact • loss of revenue due to electricity shut down, when flood depth > 1m (Source – MEA)

  26. Impact cost: summary

  27. Impact costs

  28. Impact cost: summary • Largest affected sector - direct damage of building (residential, commercial and industrial) - about 77 per cent of the total damage cost • Income loss of commercial and industrial sectors would account for approximately 15 and 7 per cent of the total damage cost respectively • Under the current condition, impact costs would be 35,302 million baht which might rise to 148,434 million baht in the future worst case scenario • over four fold increase in the impact cost

  29. Adaptation study

  30. Structural measures - ongoing • Polder system • Dikes, drainage canal, regulator and pump facilities • Water retention area (Monkey Cheek) • On-going flood protection efforts • not have enough to cope with A1FI climate change scenario at the return period higher than 10 years. Constructing Retaining Wall onthe Bank of Chao Phraya River Phrakanong Pumping Station Rama IX Retention Pond, Pathum Thani can retard the flow and retain about 16 million cubic meters of flood water

  31. Bhumibol Dam on the Ping River Sirikit Dam on the Nan River Structural measures – earlier proposal Large Storage Dam • The Kaeng Sua Ten Dam(1,125 MCM, CA 3,583 km2)on the Yom River • Controversial social and environmental impact • Other large storage dam • lack suitable site due to rapid economic development • strong protest from the environmentalist

  32. The Thames Barrier Project (England) The Maeslant Storm Surge Barrier Project(Netherlands) Structural measures – earlier proposal Barrage at the River Mouth • Proposed by the RID • Costly - 131,020 million baht in 1998 • Social and environmental problems • Can interfere navigation • Storm surge Barrier in the Upper Gulf of Thailand • controversial among local experts

  33. Raphi Phat canal capacity will be improved from 120 to be 400 m3/sec to divert flood water from the Pasak River Chornrahan Phichit Pumping Station(120 m3/sec) Structural measures – earlier proposal Diversion Channel • RID proposal - from Ayutthaya to the Gulf of Thailand (The Chao Phraya River II project) • high investment cost (42,329 million baht in 1998 for capacity of 1,100 m3/sec) • impact on social and environment especially land acquisition problem • RID (2006) alternate proposal – • improve several existing irrigation canals to divert water • Improve pumping capacity at stations on the right bank of the Bang Pakong River and on the coast

  34. T-groins Type Rock-pile Embankment Type 3 Row Concrete Pole Type Sea Wave ProtectionBamboo Type Structural measures – other practice Coastal Erosion and Wave Protection • More than 760 m of the Bang Khun Thian shoreline have been eroded • Local solution • bamboo barrier to weaken the strength of the waves hitting the coast and increase silt deposition • BMA plan • 10 T-groins along the 4.7 km shoreline • mangrove trees • budget - estimated at 388.85 million baht • Department of Marine and Coastal Resources (DMCR) • studying on the Master Plan and Practice to Solve the Problem of Coastal Erosion on Shoreline along the Upper Gulf of Thailand.

  35. Proposed Structural Measuresfor 100-year Return Period Dike improvement (up to 1.5 m):235 km on the east160 km on the west Increasing pumping capacity and canal improvement:Phasi Charoeng from 18 to be 550 m3/sec canal 27 kmSanam Chai from 36 to be 350 m3/sec canal 32.5 kmKhun Rat Phinit Chai from 30 to be 250 m3/sec canal 14.5 km Coastal erosion protection:36 km on the west43 km on the east

  36. Max. future inundation (30-yr flood) Inundated area – reduced - 744 to 362 km2 or decreased 382 km2 or 51 %. Without Proposed Adaptation measures With Proposed Adaptation measures

  37. Evaluation of the proposal Feasibility study and detail design (3 years) -148 mil. BahtConstruction cost (5 years) - 49,380 mil. BahtO & M (30 years) - 874 mil. Baht/year Economic Evaluation- Discounted rate - 10%- Net Present Value (NPV) - 16,256 mil. Baht- Benefit-cost Ratio (B/C) - 1.6- Economic Internal Rate of Return (EIRR) - 16.26% Average annual benefit = average annual flood damage reduction Conversion, Cost -> Economic cost (shadow price recommended by the WB – adopted) The B/C and EIRR reveal an attractive investment even without considering the benefits accruing from reduction of intangible damages (economic and social)

  38. Non-structural measures • Reservoir operation during flood times – rules of cooperation among • Electricity Generating Authority of Thailand (EGAT), the Royal Irrigation Department (RID), the Department of Water Resources (DWR), the Meteorological Department (TMD) and BMA • Pursue Groundwater Extraction Control regulations to reduce land subsidence • Flood Forecasting and Warning System • Well developed (by BMA, EGAT, MD, DWR, RID) • Improve accuracy of forecast and disseminate more frequently • Develop consistent Guidelines for Flood Warning

  39. Non-structural measures • Flood Insurance • Framework for flood insurance • Institutional arrangements • Disaster Management • Public Awareness and Education • Participation in International Disaster Management Networks • Effective Damage Assessment • Application of Community-Centered Approach • Highlight on Preventive Approach • Mainstreaming Climate Change • City and Land Use Control and Guidelines

  40. Non-structural measures • Flood Fighting Activity • Assurance of funds for operation of suitable flood fighting system with enough equipment, materials, and manpower through the decision of protection level; • Periodical training of inhabitants expected to join the flood fighting works; • Promulgation of a law on flood fighting to clarify the administration structure and job responsibilities of all concerned agencies, resulting in a well organized and more effective flood fighting.

  41. Institutional mechanism: highlight • Thailand Climate Change Impact and Adaptation Council • Under the Office of Prime Minister chaired by a Deputy Prime Minister • Representation - main departments and ministries • To ensure strong institutional support • Responsibilities • Establish sub-committees and/or working groups to carry on the proposed adaptation measures • Conduct scientific study and maintain knowledgebase • Set up climate strategy of Thailand • Raise public awareness on climate change • Coordinate CC activities

  42. Adaptation: implementation schedule FS = Feasibility Study DD = Detailed Design CS = Construction O&M = Operation and Maintenance IP = Implement TCCIAC = Thailand Climate Change Impact and Adaptation Council Bangkok Metropoitan Administration (BMA); Department of Marine and Coastal Resources (DMCR), MoNRE; Hydrogaraphic Department (HDD), Thai Navy; Department of Drainage and Sewerage (DDS), BMA; The Royal Irrigation Department (RID), MOAC; The Electricity Generating Authority of Thailand (EGAT); Department of Water Resources (DWR), MoNRE; Royal Thai Survey Department (RTSD); The Meteorological Department (TMD); National Disaster Warning Center (NDWC); Department of Disaster Prevention and Mitigation (DDPM); Office of Insurance Commission (OIC); Department of Fisheries (DOF); Department of Environment (DE); Department of Public Works (DPW); Traffic and Transportation Department (TTD)

  43. Summary…. • Generated science-based knowledge of socioeconomic situation and climatic factors • Developed mathematical model for simulating climate change impact the on hydrology • Assessed easily interpretable climate change impact for 2050 under different scenarios • Recommended suitable adaptation options

  44. Thank you swahid@gmail.com

  45. An upcoming event… Please contact: Dr. S M. Wahid Tel: +66 89 44 00 906 Tel: +662 524 5561 Fax: +662 524 6425 Email: swahid@gmail.com

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