Assessment of Agricultural Drought in Dak Ha and Kon Ray Districts, Central Highlands of Vietnam, Using Remote Sensing and GIS

Drought is one of the most damaging natural phenomena. Due to their extensive geographic coverage, monitoring droughts using conventional systems can be challenging. In recent years, Kon Tum province, Central Highland of Vietnam, has been experiencing severe droughts and water shortages during the dry season, causing great damage to agriculture, daily life, and the local economy. This paper presents the method of using Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) from band 4, band 5 and band 10 of LANDSAT 8 in the exhausted period from February to April in the period 2014 - 2023 to calculate the Water Supplying Vegetation Index (SWVI) and Temperature Vegetation Dryness Index (TVDI). The processing and analysis of remote sensing images were conducted on a cloud-based platform, specifically Google Earth Engine (GEE), in conjunction with ArcGIS software. The research results have shown that drought-prone areas correspond to regions with increased LST and decreased NDVI value. In addition, based on the scale of drought severity, SWVI and TVDI have demonstrated that the majority of communes within two districts experienced drought conditions during the severe drought years of 2018 and 2020. Among these, Dak To Lung, Dak To Re and Dak Ruong communes in Kon Ray district are the three communes most severely affected by drought.