JAPAN INTERNATIONAL COOPERATION AGENCY The Data Collection Survey on Road Protection against Natural Disaster (Landslide-Disaster) FINAL REPORT (1/2) December, 2012 KOKUSAI KOGYO CO., LTD. ORIENTAL CONSULTANTS CO., LTD. JAPAN CONSERVATION ENGINEERS CO., LTD. JICA KOKUSAI KOGYO CO., LTD. The Data Collection Survey on Road Protection ORIENTAL CONSULTANTS CO., LTD. against Natural Disaster (Landslide) (Final Report) JAPAN CONSERVATION ENGINEERS CO., LTD. I Location Map ᎓ᎶᎪᎨᎻᎰᎰᎶᎵ፧ᎶᎭ፧᎚ᎻᎼᎫᏀ፧ᎈᎹᎬᎨ፧ ᎋᎬᎻᎨᎰᎰᎳᎳ፧᎔ᎨᎷ፧ &HQWUDO3URYLQFH 8YD3URYLQFH 6DEDUDJDPXZD 0DWDOH 3URYLQFH .DQG\ ⛿ ε ε .HJDOOH ᭷ᮚᮔ :HVWHUQ3URYLQFH ᭓ᮕᮏ 'LVWULFW 1XZDUDε %DGXOOD (OL\D ᭖ᮖ᭪ᮔ ε .DOXWDUD 5DWQDSXUD I JICA KOKUSAI KOGYO CO., LTD. The Data Collection Survey on Road Protection ORIENTAL CONSULTANTS CO., LTD. against Natural Disaster (Landslide) (Final Report) JAPAN CONSERVATION ENGINEERS CO., LTD. II Photos i) Soaring escarpment with fresh traces of collapse at vi) A cracked road, Badulla Natio nal Road (NR) A005 ii) Head scarp of a divided landslide just beside the vii) A cracked house, Badulla main road at NR A016 iii) Typical "toe-eroded" landslide seen at NR A007 viii) An interview to the residents concerning wi th landslide disaster iv) Escarpment with risks of rock slides at NR A026 ix) An interview at estate workers' residences v) Warning signboard "Earth slip ahead!" at NR A005. x) Discussion with villagers II JICA KOKUSAI KOGYO CO., LTD. The Data Collection Survey on Road Protection ORIENTAL CONSULTANTS CO., LTD. against Natural Disaster (Landslide) (Final Report) JAPAN CONSERVATION ENGINEERS CO., LTD. III Abbreviations ADB Asian Development Bank B/C Benefit Cost Ratio CEA Central Environmental Authority CL Critical Line DDMCU District Disaster Management Coordination Unit DiMCEP The Disaster Management Capacity Enhancement Project DOM Department of Meteorology DMC Disaster Management Center DRM Disaster Risk Management DS Divisional Secretary EIA Environmental Impact Assessment EIRR Economic Internal Rate of Return EL Evacuation Line ERD External Resources Department EWS Early Warning Systems FF Fact Finding F/S Feasibility Study Fs Safety Factor G/A Grant Agreement GDP Growth Domestic Product GN Grama Niladhari GOSL Government of Sri Lanka HC Highland Complex IEE Initial Environmental Examination ILSMP Integrated Landslide Mitigation Project JET Japanese Expert Team JICA Japan International Cooperation Agency KC Kadugannawa Complex L/A Loan Agreement LAA Land Acquisition Act LRRMD Landslide Research and Risk Management Division MDM Ministry of Disaster Management MoPH Ministry of Ports and Highways NBRO National Building Research Organization NCDM National Council for Disaster Management NDRSC National Disaster Relief Service Center NGO Non Governmental Organization NIRP National Involuntary Resettlement Policy NPD National Planning Department NPV Net Present Value ODA Official Development Assistance PWD Public Work Department RAP Resettlement Action Plan RDA Road Development Authority Rs. Sri Lankan Rupee (Local Currency) SLUMDMP Sri Lanka Urban Multi-Hazard Disaster Mitigation Project TOR Terms of Reference UNDP United Nations Development Programme USAID US Agency for International Development VOC Vehicle Operation Cost WL Warning Line III JICA KOKUSAI KOGYO CO., LTD. The Data Collection Survey on Road Protection ORIENTAL CONSULTANTS CO., LTD. against Natural Disaster (Landslide) (Final Report) JAPAN CONSERVATION ENGINEERS CO., LTD. IV Definitions of terms New ODA Loan Project Landslide Disaster Protection Project of the National Road Network Rank A National road sections in high risk regions National road sections of high priority for investigationέ Rank B National road section where landslide disaster occurred before and landslide countermeasures need to be implemented based on the detailed investigation in Rank A sections. Road disaster management model areas. Rank C National road section where landslide disaster occurred before, and urgent landslide countermeasures need to be implemented based on the detailed investigation in Rank B sections. IV /RFDWLRQ0DS 3KRWRV $EEUHYLDWLRQV 'HILQLWLRQVRI7HUPV CONTENTS Page: 1 Introduction .................................................................... 1-1 1.1 General ........................................................................................................ 1-1 1.2 Objectives of the Project ............................................................................. 1-1 1.3 Survey area and target national roads ......................................................... 1-2 1.4 Implementation structure of the survey ...................................................... 1-2 1.4.1 JICA Survey Team .......................................................................... 1-2 1.4.2 Government offices and organizations related ............................... 1-3 2 Outline of survey area and target national roads ............... 1 2.1 Natural condition of the survey area ............................................................... 1 2.1.1 Landforms and geology ...................................................................... 1 2.1.2 Climate ................................................................................................ 5 2.2 Social and economic condition of the survey area ................................... 2-10 2.2.1 Population and households ........................................................... 2-10 2.2.2 Economy and industries ................................................................ 2-11 2.2.3 Social conditions ........................................................................... 2-15 2.2.4 Road network and traffic conditions ............................................. 2-16 2.3 Landslides in the survey area .................................................................... 2-21 2.3.2 Landslide disaster in the survey area ............................................ 2-23 2.3.3 Landslide disaster on the target national roads ............................. 2-24 2.3.4 Landslide hazard map of NBRO ................................................... 2-26 2.3.5 Social aspects / background of landslide ...................................... 2-27 3 Current status of road protection against landslide disaster3-1 3.1 Road Sector ................................................................................................. 3-1 3.1.1 Road Development Authority (RDA) ............................................. 3-1 3.1.2 Road sector policy and development plan ...................................... 3-4 3.1.3 Current conditions and issues in road sector .................................. 3-6 3.1.4 Landslide countermeasures of RDA ............................................... 3-8 3.1.5 Trend of other donor agency and nations ..................................... 3-12 3.1.6 Road development needs in the future .......................................... 3-13 3.2 Landslide-disaster countermeasures sector............................................... 3-14 3.2.1 National Building Research Organization (NBRO) ..................... 3-14 3.2.2 Development policy and plan on landslide-disaster sector ........... 3-17 3.2.3 Development plan of NBRO for landslide disaster risk management3-18 3.2.4 Trend of other donor agency and nations ..................................... 3-19 3.2.5 NBRO’s Landslide Countermeasures ........................................... 3-20 3.2.6 Guidelines for Slope Management and Slope Protection (technical guidelines) ..................................................................................... 3-21 3.2.7 NBRO’s landslide countermeasures ............................................. 3-23 4 Risk assessment and analysis on landslide disaster ...... 4-1 4.1 Examples of major landslide disaster on the target national roads ............. 4-1 4.2 Outline of risk assessment and analysis method......................................... 4-6 4.3 Screening of “Rank A” (National road sections in high risk regions) ........ 4-8 4.3.1 Partitioning of national road ........................................................... 4-8 4.3.2 Screening of Rank A section ........................................................ 4-11 4.3.3 Screening of Rank A area ............................................................. 4-12 4.4 Screening of “Rank B” (National road areas of high priority for investigation) .................................................................................................................. 4-14 4.5 Screening of “Rank C” sections (“Road disaster management model areas”) and their prioritization ..................................................................................... 4-18 4.5.1 Screening of Rank C areas ............................................................ 4-18 4.5.2 Priority setting in Rank C areas .................................................... 4-26 4.5.3 Priority setting in Rank B areas .................................................... 4-26 4.5.4 Method of risk analysis ................................................................. 4-27 4.5.5 Setting method of the disaster extent ............................................ 4-36 5 Aid approaches and strategies to the countermeasures for landslide disaster ........................................................... 5-1 5.1 Subjects for landslide countermeasure on the national roads ..................... 5-1 5.1.1 Situation of RDA and NBRO ......................................................... 5-2 5.1.2 Effective countermeasures for landslide