Geographia Technica, Vol 20, Issue 1, 2025, pp. 11-20
SPATIAL DROUGHT OCCURRENCE AND DISTRIBUTION USING DATA FROM SENTINEL-2 SATELLITE AND VEGETATION INDICES
Chaiphat PLYBOUR, Yannawut UTTARUK 
, Phaisarn JEEFOO , Natcha LAOSUWAN, Teerawong LAOSUWAN
ABSTRACT: In recent years, drought has become a significant challenge for Thailand. Monitoring and surveillance of drought occurrences are therefore crucial. This research aims to present the analysis results of vegetation conditions and climate change in Maha Sarakham Province using NDVI and VCI indices, along with rainfall data from 2021 to 2023. The NDVI analysis found that the peak index in each year differed, with the highest value in 2021 being 0.395 in August, 2022 being 0.384 in September, and 2023 being 0.253 in November. The lowest index values were observed in different months each year. The VCI analysis showed similar results, with the highest and lowest indices reflecting seasonal changes. Rainfall plays a crucial role in determining vegetation conditions, with the highest rainfall observed in August and subsequently declining in the following months. Furthermore, the analysis of drought severity indicated that rainfall amounts are related to changes in the VCI, with 2021 experiencing the most severe drought, while in 2023, the drought was visibly reduced. This study concludes that there is a significant correlation between rainfall and vegetation conditions, and changes in the indices can be used as indicators to effectively monitor climate change and manage natural resources in the future.
Keywords: Remote Sensing, Spatial Drought, NDVI, VCI, Sentinel-2
Full article here