Climate change vulnerability assessment for Boeung Chhmar Mekong Water Dialogues Peter-John Meynell, Kimsreng Kong, Pheakdey Sorn and Vanny Lou 1 The designation of geographical entities in Citation: Meynell, P. J., Kong, K., Sorn, this book, and the presentation of the Pheakdey. and Lou, V. (2014). Climate material, do not imply the expression of change vulnerability assessment for any opinion whatsoever on the part of Boeung Chhmar. Thailand: IUCN. IUCN or the concerning the legal status of 120pp. any country, territory, or area, or of its authorities, or concerning the delimitation Cover photo: © IUCN Cambodia of its frontiers or boundaries. The views expressed in this publication do not Layout by: Ria Sen/Nguyen Thuy Anh necessarily reflect those of IUCN, the Ministry of Foreign Affairs of Finland, Produced by: IUCN Southeast Asia European Union or any other participating Group organizations. Available from: IUCN Asia Regional This publication has been made possible Office, 63 Soi Prompong, Sukhumvit 39, by funding from the Ministry of Foreign Wattana 10110 Bangkok, Thailand Affairs for Finland and European Union. Tel: +66 2 662 4029 Published by: IUCN Asia in Bangkok, www.iucn.org/mekong_water_dialogues Thailand Copyright: © 2014 IUCN, International Union for Conservation of Nature and Natural Resources Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this publication for resale or other commercial purposes is prohibited without prior written permission of the copyright holder. 2 Contents Acknowledgements .................................................................................................. 9 Acronyms and abbreviations ................................................................................ 10 Executive summary ................................................................................................ 11 1 Introduction ...................................................................................................... 17 2 Methods ............................................................................................................ 19 2.1 Wetland and climate change case studies guidance ................................... 19 2.2 VCA ............................................................................................................. 21 2.3 Climate Change Adaptation and Mitigation Methodology (CAM) ................ 21 2.4 Determining ecological response to climate change ................................... 25 2.4.1 Comfort zones ...................................................................................... 26 3 Description of Boeung Chhmar ...................................................................... 28 3.1 Hydrological characteristics......................................................................... 30 3.1.1 The Tonle Sap system .......................................................................... 30 3.1.2 Boeung Chhmar ................................................................................... 31 3.2 Habitats – area and extent .......................................................................... 32 3.3 Seasonal ecological processes ................................................................... 37 3.4 Key species ................................................................................................. 38 3.4.1 Fish ....................................................................................................... 38 3.4.2 Invertebrates ......................................................................................... 40 3.4.3 Large water birds .................................................................................. 41 3.4.4 Mammals .............................................................................................. 43 3.4.5 Reptiles ................................................................................................. 43 3.5 Community conservation sites .................................................................... 45 3.6 Communities and key livelihood activities ................................................... 45 3.7 Perceived non-climate threats and changes ............................................... 46 4 Management and institutional situation ........................................................ 47 4.1 Ramsar site ................................................................................................. 47 4.2 Management plan ....................................................................................... 48 4.3 Abolition of fishing lot #6 and implications ................................................... 48 5 Climate – present and future .......................................................................... 49 5.1 Current climate ............................................................................................ 49 3 5.2 Future projections ....................................................................................... 50 5.2.1 Climate projection methods .................................................................. 51 5.2.2 Temperature changes........................................................................... 51 5.2.3 Rainfall.................................................................................................. 56 5.2.4 Storms and extreme events .................................................................. 59 5.3 Local perceptions of climate trends and extreme events ............................ 60 5.4 Hydrology and habitat changes ................................................................... 61 6 Vulnerability assessment ................................................................................ 69 6.1 Summary of main climate threats ................................................................ 69 6.2 Vulnerability of key physical and ecological processes ............................... 70 6.3 Key habitats ................................................................................................ 75 6.3.1 Open water ........................................................................................... 75 6.3.2 Gallery forest – alongside Tonle Sap and along river banks................. 76 6.3.3 Mixed flooded shrubland with trees ...................................................... 78 6.3.4 Flooded grassland ................................................................................ 78 6.4 Vulnerability assessments of key plant species .......................................... 79 6.4.1 Swamp forest trees – Barringtonia sp ................................................... 79 6.4.2 Shrubs – Sesbania sesban ................................................................... 80 6.4.3 Shrubs – Mimosa pigra ......................................................................... 81 6.5 Vulnerability assessments of key fauna ...................................................... 81 6.5.1 Fish ....................................................................................................... 81 6.5.2 Eel ........................................................................................................ 85 6.5.3 Crustacea - Rice field Shrimp – Machrobrachium lanchesteri .............. 86 6.5.4 Snails – Pila scutata and Pomacea canaliculata .................................. 88 6.5.5 Reptiles – Water snakes ....................................................................... 89 6.5.6 Turtles................................................................................................... 91 6.5.7 Large water birds .................................................................................. 93 6.5.8 Mammals .............................................................................................. 93 7 Vulnerability of livelihood activities in Boeung Chhmar .............................. 94 7.1 Fishing ........................................................................................................ 94 7.2 Fish raising ................................................................................................ 101 7.3 Fishing supporting activities ...................................................................... 101 7.4 Water supply ............................................................................................. 101 4 7.5 NTFP collection ......................................................................................... 102 7.6 Ecotourism ................................................................................................ 102 8 Conclusion ..................................................................................................... 103 References ............................................................................................................ 105 Annex 1: CAM matrices of the key habitats ....................................................... 107 Annex 2: CAM matrices of selected species ..................................................... 114 Annex 3: CAM matrices of fish species from Mekong ARCC Fisheries study 118 5 List of figures and tables Figures Figure 2.1 Nine steps approach for wetland and climate change case studies Figure 2.2 Vulnerability assessment and adaptation process Figure 2.3 Climate change impact and vulnerability assessment process Figure 2.4 Parameters and issues considered in the baseline and vulnerability