Analysis and investigation on spatio-temporal dynamic pattern of drought in Thailand

Abstract

The spatio-temporal analysis to evaluate drought conditions in Thailand from 2000 to 2020 using indices, are SPI, NDVI, and VCI derived from MODIS based on GEE platform. This study found that NDVI could be used to assess and monitor the drought conditions in these regions. The correlation analysis between the SPI and VCI indicates the potential of VCI in measuring the direct impact of rainfall on vegetation dynamics. Analysis showed that VCI was found to be stronger in providing a detailed description of the vegetation dynamics with the corresponding level of precipitation received. The average NDVI was 0.59, the highest in 2017 at 0.74, and the lowest value at 0.39 in 2001. The average VCI was 54%, the highest in 2017 at 86%, and the lowest value at 21% in 2001. SPI is obtained from the rainfall data. The SPI value of -2.11 was the lowest with the drought severity level in 2004 and in 2000 was the highest SPI of 1.12 where were moderate to extreme wet with no drought severity level.