The Study of Risk Levels of Flood in the Southern Region by Applying Geographic Information System (GIS)

Abstract

This study applied a Geographic Information System (GIS) and Analytical Hierarchy Process (AHP) model to analyze the level of flood risk in the southern region of Thailand. Seven factors were used for analysis, including average rainfall data for the past 10 years, distance from the main river, soil types, obstacles to water flow, elevation above mean sea level, slope of the land, and land use. These factors were overlaid and weighted based on the assessment of experts to classify the flood risk into five levels: very low, low, moderate, high, and very high. The results showed that the factor that most influenced flood risk in the southern region of Thailand was average rainfall data for the past 10 years, and the highest level of flood risk was found to be 9.64% of the southern region. The areas at highest risk were those close to the main river, low-lying areas, and coastal areas. Therefore, it is recommended that both structural and non-structural measures be implemented to mitigate the impact of floods in these areas.