ISSN 0386－5878 Technical Note of PWRI No.4066 Factor Analysis of Water-related Disasters in Sri Lanka June 2007 The International Centre for Water Hazard and Risk Management PUBLIC WORKS RESEARCH INSTITUTE 1-6, Minamihara Tukuba-Shi, Ibaraki-Ken, 305-8516 Copyright ○C (2007) by P.W.R.I. All rights reserved. No part of this book may be reproduced by any means, nor transmitted, nor translated into a machine language without the written permission of the Chief Executive of P.W.R.I. この報告書は、独立行政法人土木研究所理事長の承認を得て刊行したものであ る。したがって、本報告書の全部又は一部の転載、複製は、独立行政法人土木研 究所理事長の文書による承認を得ずしてこれを行ってはならない。 Technical Note of PWRI No.4066 Factor Analysis of Water-related Disasters in Sri Lanka by Junichi YOSHITANI Norimichi TAKEMOTO Tarek MERABTENE The International Centre for Water Hazard and Risk Managemant Synopsis: Vulnerability to disaster differs considerably depending on natural exposure to hazards and social conditions of countries affected. Therefore, it is important to take practical disaster mitigating measures which meet the local vulnerability conditions of the region. Designating Sri Lanka as a research zone, this research aims to propose measures for strengthening the disaster mitigating system tailored to the region starting from identifying the characteristics of the disaster risk threatening the country. To this end, we identified the country’s natural and social characteristics first, and then analyzed the risk challenges and their background as the cause to create and expand the water-related disasters. Furthermore, we also analyzed the system of the socio-economic structure, the evacuation behavior of the affected people and related experience to disasters. Key Words: water-ralated disaster, risk management, case study, disaster prevention plan List of Abbreviations ADB Asian Development Bank ASEAN Association of Southeast Asian Nation CNO Center for National Operations CRED Centre for Research on the Epidemiology of Disasters DDMA District Disaster Management Authority Div DMA Division Disaster Management Authority DS Division Secretary EM-DAT Emergency Disasters Data Base FTA Free Trade Agreement GA Government Agent GRP Gin Ganga Regulation Project IMF International Monetary Fund IOC Intergovernmental Oceanographic Commission IOTWS Indian Ocean Tsunami Warning and Mitigation System IPKF India Peace Keeping Force ISDR International Strategy for Disaster Reduction JST Japan Standard Time JVP Janatha Vimukthi Peramuna (People's Liberation Front) LHMP Landslide Hazard Mapping Programme LTTE The Liberation Tigers of Tamil Eelam MAIMD Ministry of Agriculture, Irrigation and Mahaweli Development MDMHR Ministry of Disaster Management and Human Rights MDRS Ministry of Disaster Relief Services MWESW Ministry of Women Empowerment and Social Welfare NBRO National Building Research Organization NCDM National Council for Disaster Management NDMC National Disaster Management Center PA People's Alliance PRSP Poverty Reduction Strategy Paper PTWC Pacific Tsunami Warning Center SLFP Sri Lanka Freedom Party TAFLOL Task Force for Logistics and Law and Order TAFREN The Task Force to Rebuilding Nation TAFRER Task Force for Rescue and Relief UNCHS United Nations Centre for Human Settlements (Habitat) UNDP United Nations Development Programme UNESCO United Nations Educational, Scientific and Cultural Organization UNP United National Party UPFA United People's Freedom Alliance USGS United States Geological Survey UTC Coordinated Universal Time WMO World Meteorological Organization Contents 1. General Information on Sri Lanka ................................................................................................ 1 1.1 Social Economy (S01), (S16), (S18) .......................................................................................... 1 1.2 Natural Conditions (S01), (S03), (S19) ...................................................................................... 2 2. Regional and Local Features ........................................................................................................ 5 (1) Meteorological Features (S03), (S19)............................................................................. 5 (2) Hydrological and Geographical Features (S03), (S19), (S23) ............................................ 7 (3) Hydrological and Meteorological Network (S03), (S20), (S23) ...................................... 14 3. Social Structure .......................................................................................................................... 19 (1) History (S16) ............................................................................................................ 19 (2) Political System (S01), (S04), (S07), (S14), (S16), (S19), (S20) ..................................................... 20 (3) Provinces and Districts, Self-government (S01), (S14), (S16), (S20) .................................. 28 (4) Economic Situation (S16), (S21) .................................................................................. 30 (5) Industrial Situation (S16), (S21), (S22) ............................................................................ 33 (6) Culture, Religion, Language (S02), (S16), (S24) ............................................................. 37 (7) Gender (S24) ............................................................................................................. 39 (8) Minorities (S02), (S24) ................................................................................................. 41 4. Overview of Water Damage in Sri Lanka (S15) ............................................................................ 47 4.1 Overview of Floods and Landslide Disasters (S03), (S07), (S15), (S23) .................................... 50 (1) Period .................................................................................................................... 50 (2) Frequency .............................................................................................................. 53 (3) Characteristics ....................................................................................................... 55 (4) List of Damages ..................................................................................................... 67 (5) Measures (structural, non-structural) ..................................................................... 70 4.2 Overview of the December 2004 Tsunami Damage in Sri Lanka (S05), (S06), (S09), (S12), (S13)79 (1) General Overview .................................................................................................. 79 (2) Human Damage ..................................................................................................... 89 (3) Social Damage ....................................................................................................... 90 (4) Disaster Countermeasures ..................................................................................... 92 5. Damage Analysis ........................................................................................................................ 96 5.1 Damage Analysis of the May 2003 Flood and Landslide Disaster ............................. 96 (1) Flood and Landslide Disaster of Kalu Ganga (S03), (S07), (S15), (S23) ............................ 96 (2) Flood and Landslide Disaster of Gin Ganga (S03), (S07), (S15), (S23) ............................ 101 (3) Flood and Landslide Disaster of Nilwala Ganga (S03), (S07), (S15), (S23) ..................... 107 5.2 Damage Analysis of the December 2004 Tsunami (S05), (S06), (S08), (S09), (S12), (S13) ......... 114 Appendix: List of Documents Related to Sri Lanka i List of Tables and Figures Fig. 1 Topographic Map ............................................................................................................... 2 Fig. 2 Geological Map.................................................................................................................. 4 Fig. 3 Climatic Division Map ....................................................................................................... 5 Fig. 4 Frequency of Cyclones in Ceylon ...................................................................................... 7 Fig. 5 Rainfall Distribution Map .................................................................................................. 8 Fig. 6 River Basins Map ............................................................................................................. 10 Fig. 7 Surface Water Potential Map ........................................................................................... 12 Fig. 8 Spatial Variability of Annual Runoff and Precipitation in Major Rivers ....................... 13 Fig. 9 Spatial Distribution of Meteorological Stations ............................................................... 14 Fig. 10 Spatial Distribution of Gauging Stations ....................................................................... 17 Fig. 11 Flood Warning System of Kelani Ganga ........................................................................ 18 Fig. 12 Map of Local Administrations ....................................................................................... 28 Fig. 13 Path of the Cyclone that Affected the Concentrated Heavy Rain ................................ 51 Fig. 14 May 6 - 13, 2003 Weekly Rainfall ................................................................................. 52 Fig. 15 Daily Rainfall in May 2003 Observed at Ratnapura Rain-gauge Station .................... 53 Fig.