Geospatial Mapping of Drought Risk in Thuan Bac District, Vietnam Using Landsat 8 OLI-TIR Data

Tran Thi Thu Trang, Nguyen Thi Le Hang

Abstract: This study evaluates drought risk in Thuan Bac District, Ninh Thuan Province, Vietnam, between 2018 and 2023 using Landsat 8 OLI-TIR imagery. Geospatial indices including the Temperature Vegetation Dryness Index (TVDI), the Normalized Difference Vegetation Index (NDVI), and surface temperature data were applied to classify drought severity into five categories. The resulting maps were validated with field observations and indicate that over 60% of the district experienced moderate to severe drought during the study period. Areas with minimal or extreme drought conditions accounted for a smaller proportion. This case study illustrates the effectiveness of remote sensing in drought risk assessment and provides vital insights for sustainable land and water resource management in semi-arid regions.

Keywords: Drought, Remote sensing, Landsat 8, TVDI, Thuan Bac