1 2 Photos: Lam Pa Chi River, by Georg Meier Table of Contents 1 Introduction ................................................................................................................................. 9 2 Data acquisition and data management ......................................................................... 10 2.1 Lam Pa Chi River Basin Information System ................................................................................ 10 2.1.1 Introduction ........................................................................................................................... 10 2.1.2 Structure ................................................................................................................................ 10 2.1.3 Access and sharing data ........................................................................................................ 11 2.1.4 Additional important functions ............................................................................................. 12 2.2 Data availability, data stored on Lam Pa Chi RBIS ....................................................................... 12 3 Lam Pa Chi River Basin description ................................................................................. 13 3.1 Location ....................................................................................................................................... 13 3.2 Lam Pa Chi as part of Mae Klong River Basin ............................................................................... 14 3.3 Administrative boundaries and governance ................................................................................ 15 3.4 Climate ......................................................................................................................................... 16 3.5 Hydrology and hydrological network ........................................................................................... 19 3.6 Geology and groundwater aquifers ............................................................................................. 21 3.7 Land Use....................................................................................................................................... 23 3.8 Crop pattern ................................................................................................................................. 25 3.9 Soil types ...................................................................................................................................... 26 3.10 Demography and Water Use ..................................................................................................... 28 4 Climatic trends and predictions ........................................................................................ 29 4.1 Identification of climate change in the region ............................................................................. 29 4.2 Change in future of minimum temperature ................................................................................ 31 4.3 Change in future of maximum temperature ............................................................................... 33 4.4 Change in future of precipitation ................................................................................................ 35 4.5 Comments on climate change in the region ................................................................................ 36 5 Water Balancing ...................................................................................................................... 37 5.1 Introduction to WEAP (Water Evaluation and Planning) ............................................................. 37 5.2 Hydrological Inputs ...................................................................................................................... 38 5.3 Agricultural demand .................................................................................................................... 39 5.4 Domestic demand ........................................................................................................................ 39 5.5 Scenarios ...................................................................................................................................... 39 5.6 Results .......................................................................................................................................... 40 6 Vulnerability Assessment .................................................................................................... 45 6.1 Introduction to risk and vulnerability assessment ...................................................................... 45 6.1.1 Risks and Disaster Risk Definition .......................................................................................... 45 6.2 Justification: why floods, droughts and erosion .......................................................................... 47 6.3 Flood vulnerability ....................................................................................................................... 48 6.3.1 Background ........................................................................................................................... 48 6.3.2 Objectives .............................................................................................................................. 49 6.3.3 Methodology ......................................................................................................................... 49 6.3.4 Results ................................................................................................................................... 51 3 6.4 Drought vulnerability ................................................................................................................... 55 6.4.1 Background ........................................................................................................................... 55 6.4.2 SPI/SRI Analyses .................................................................................................................... 56 6.5 Vulnerability against soil erosion ................................................................................................. 61 6.5.1 Background ........................................................................................................................... 61 6.5.2 Objectives .............................................................................................................................. 61 6.5.3 Methodology – RUSLE ........................................................................................................... 61 6.5.4 Results ................................................................................................................................... 66 6.5.5 Recommendations for further investigations ........................................................................ 77 7 Potential Ecosystem-based Adaptation Measures ...................................................... 79 7.1 Introduction ................................................................................................................................. 79 7.2 EbA – An example on Natural bank stabilization ......................................................................... 81 7.2.1 General description ............................................................................................................... 81 7.2.2 Location ................................................................................................................................. 82 7.2.3 Benefits .................................................................................................................................. 82 7.2.4 Technical specification .......................................................................................................... 82 7.3 EbA - An example on Forest riparian buffers / Buffer strips and hedges .................................... 84 7.3.1 General description ............................................................................................................... 84 7.3.2 Location ................................................................................................................................. 84 7.3.3 Benefits .................................................................................................................................. 85 7.3.4 Technical specification .......................................................................................................... 87 7.4 EbA – An example on Terracing in pineapple cultivation ............................................................ 88 7.4.1 General description ............................................................................................................... 88 7.4.2 Location ................................................................................................................................. 88 7.4.3 Benefits .................................................................................................................................. 89 7.4.4 Technical specification .......................................................................................................... 90 7.5 EbA – An example on Infiltration basin in urban areas ............................................................... 91 7.5.1 General description ..............................................................................................................