Spatial drought evaluation using MODIS Normalized Difference Vegetation Index and Land Surface Temperature data in the east side of Ping river Kamphaeng Phet province

Abstract

This study aims to evaluate spatial drought using the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) based on MODIS data, in the east side of Ping River, Kamphaeng Phet province. The process that include, collected 16-day composite of NDVI and 8-day composite of LST data from MOD13A1 and MOD11A2 product during dry season in November 2015 to April 2016. Then calculated the Normalized Vegetation Supply Water Index (NVSWI) to assess five levels of drought class, include severe drought, moderate drought, slight drought, normal drought, and wet area. Moreover, the study also analyzes level of drought classes with environmental properties. The results show that, when considered the NDVI graphs at that time, the NDVI values ​​tend to decrease continuously from November to April, while the graph of LST is higher. The average of NDVI and LST values ​​equal 0.481 and 34.2 °C, respectively. November was the month with the highest average of NDVI and April provide the highest average of LST. For drought Index analysis found that the severe drought area cover 0.86%, moderate drought 47.19%, slight drought 48.59%, normal or no drought 3.37%, and not appear the wet area class. Analysis of drought levels and environmental properties found that mostly of moderate to severe drought classes area that appear in rice field (57.14%) and sugarcane (19.27%), and the soil type is sandy loam (45.19%). There are 308 villages in these drought classes (54.23%). This result that corresponds to drought conditions in the actual area. Therefore, it can be concluded that vegetation index and surface temperature can be used to visualize spatial droughts, especially agricultural drought.