Assessing Flood and Drought Risks Using Potential Surface Analysis: A Case Study of the Ping River Basin

Abstract

Over the past decades, the Ping River Basin has experienced recurring floods and droughts. Although these events have not been severe, they have nonetheless caused damage to lives and property in the affected areas. This study aims to assess the spatial potential for analyzing flood and drought risk areas by utilizing physical data such as land use, elevation (DEM), and rainfall. Extreme indices, including the annual maximum one-day rainfall and consecutive dry days (CDD), were factors in this study. Geographic Information System (GIS) and spatial analysis techniques were applied to identify areas prone to these hydrological hazards. The study found that, in the study area, 56% of the land had a low risk of flooding, and 36% had a medium risk. Most of the flood risk areas were located in lowland areas near rivers. For drought risk, 30% of the area had a high risk, and another 30% had a very high risk. These drought risk areas were mostly agricultural areas that depended on rainfall and received low average annual rainfall. In the future, flood risk areas are expected to remain stable at about 52% on average, and flood risk areas could increase by about 47% between 2023 and 2100. Meanwhile, drought risk areas are expected to stay stable at about 43% on average, and drought risk areas could decrease by about 57% between 2023 and 2100. The output from this study can be used as a guide for managing water use, based on the physical characteristics of the land in the Ping River Basin. This is especially important in lowland areas that may face problems with both floods and droughts, now and in the future. The study can be used for planning water management, especially by local agencies in the area.