Development of a Drought Risk Index for Assessing Vulnerable Areas Using Satellite-Derived Indices

Abstract

Thailand faces increasing drought severity due to climate change, which contributes to global climatic anomalies and reduces rainfall, as seen in the 2019 and 2020 droughts. Monitoring and tracking drought conditions are crucial for effective response and management. Remote sensing technologies, such as satellite data, and geographic information systems (GIS) are vital for analyzing and monitoring drought-related information. The Drought Risk Index (DRI) was developed by integrating physical data, including land use and irrigation areas, with satellite-derived indices such as NDVI, LST, VHI, SMAP, and RFI. This approach identifies drought-prone areas and characterizes drought impacts on meteorology and agriculture. The system provides daily updates and early warnings at the sub-district level, enabling real-time drought monitoring. Validation of the DRI against agency data revealed an average accuracy of 78% when compared with the Department of Disaster Prevention and Mitigation (DDPM) records. The index effectively identifies drought-prone areas, offering a preliminary tool for agencies and communities to use for better preparedness and sustainable management.