Author(s): Phrakonkham Sengphrachanh, So Kazama, Komori Daisuke, Sopha Soliya
Keywords: Flood; Climate change; Land use change; Hazard map;
Abstract: Flooding in Laos has a significant impact on both economic and sociological. Heavy rainfall is one of the important factors to influent the magnitude of flood events. Therefore, it is important to understand the probability of rainfall in different return period and sensitivity of hazard area to the change in rainfall. This study, rainfall data from 33 stations and 30 years data length from 1970 to 2000 were used to generate the rainfall probability contour in different return period after that the integrated hazard map was used for comparison between the increase of rainfall intensity area and hazard area. We have developed an integrated hazard based on the combining 3 hazard maps which are flood, landslide and climate change hazard map. Analytical Hierarchy Process (AHP) is the tool for multi-criteria decision making. This method used AHP as a tool to integrate the different hazard maps. AHP is used to provide the relative weights of each hazards map. It is necessary to understand the relative importance of each hazard map, by using the pairwise comparison matrix to compare their significance. The value of each row in the pairwise comparison was determined based on the judgment of experts. The integrated hazard map divided into 4 categories as low hazard, medium hazard, high hazard, and very high hazard. The results show that the total percentage of hazard areas in high rainfall intensity increase around 20 %.