The application of GIS and AHP to time series satellite image data for the evaluation of agricultural drought

Agricultural drought is considered as one of the critical problems which cause a decrease in crop production. In this study, a methodology to determine the drought index used for the comprehensive evaluation of agricultural drought was proposed by applying GIS technology and AHP (Analytical Hierarchy Process) method to time series satellite image data. Firstly, VCI, TCI, VHI, NVSWI and WCI were calculated in GIS using the sequence MODIS data, and the change trend of drought according to the characteristic of each drought index during the growing season from 2012 to 2021 was analyzed. Secondly, the contribution of each drought index to the drought assessment of the research area was investigated by calculating the SPI from the sequential CHIRPS data and analyzing its correlation with those drought indices. Then, AHP method was used to calculate the weight of each drought index to the drought assessment of research area. Finally, the comprehensive drought index capable of representing those drought indices was developed by applying the weight of each drought index and used to evaluate the agricultural drought of the research area. The present study provides a useful methodology to develop a comprehensive drought index capable of representing the agricultural drought status of target area.