Assessing the flood risk area of Southern Thailand with an integrated curve number and flow accumulation approach

Land use/land cover and the area elevation are two major factors which play important roles in flooding. This paper aims to assess the flood risk area by integrating GIS-based analytical flooding model with a widely used SCS-Curve Number method. The simulated flood risk area of the southern peninsular of Thailand by comparing the flood occurred area detected by the satellite of 2011. Results show strong spatial connection between land use types and flood stage elevation. Therefore, land use planning should be addressed for flooding solution in southern Thailand to avoid lives and properties lost. Surface runoff occurs when the rate of precipitation exceeds the infiltration rate. This process is affected by factors associated with rainfall, including watershed characteristics, such as size, shape, topography and vegetation. There are a number of models for computing surface runoff in terms of runoff depth and runoff volume. The aim of this section is to investigate the influences of land use on surface runoff, the SCS Curve number method was selected to estimate the surface runoff in this study, as land use is one of the input factor use in this model.