Remote Sensing Indexes Assessment for Drought Monitoring Using Sentinel Satellite Imagery: A Case Study from Natanz County, Iran

In recent years, the problem of climate change and decrease in rainfall has become a big challenge in Iran, so it’s monitoring and control is very vital and necessary. In addition to the classical methods, nowadays with the progress of the space industry in the world, the use of remote sensing techniques has greatly helped to detect and monitor drought. The science of remote sensing and the use of satellite images is considered a useful and optimal tool for drought monitoring. In this project, we investigated the occurrence of drought using satellite images and remote sensing techniques. In this way, we have calculated the drought-related remote sensing indicators, including NDVI, VCI, TCI, and VHI, in the six-year period between 2015 and 2021 for Natanz county located in Isfahan province. In order to calculate the indicators, Sentinel satellite data was used, and to calculate the Standard Rainfall Index (SPI), data from the synoptic station of Natanz county was used. According to the general results obtained from the indicators, currently the drought situation in the southwestern region of this area has been increasing compared to the last five years, and in other regions we are witnessing the growth and occurrence of drought sporadically. The results of this research show that the best index for calculating and monitoring drought is the VCI index because it has a higher correlation with meteorological data and the SPI index.