Assessment of Drought in Mithi, Thar Using Satellite based Indices and Geoinformatics Techniques

Abstract

Drought is an incessant process in Thar, Pakistan. The extent of droughts needs to be assessed for better planning of landuse in future. The satellite data from LANDSAT 7, 8, MODIS MOD13Q1 was acquired from United States Geologic Survey (USGS) and precipitation data of TRMM was collected from GIOVANNI for the years from 2010 to 2019. Various indices including NDVI, NDMI, LST, SPI, and DI were calculated and compared with post-drought images of our targeted area and the maps were developed for Spatio-temporal analysis. The results show that vegetation in Mithi improved due to enhanced NDVI from 2010 to 2012 and a declined was observed from 2013 to 2015 with an extreme drought in 2014. The effect of the previous drought on vegetation were calculated to be negative, indicating below- average rainfall. The results showed the TRMM satellite’s over-estimation in calculating precipitation or rainfall data. The precipitation and NDVI values were improved throughout 2010 to 2013 due to continuous rainfall which overcome the earlier drought in that region. Due to El -Niño’s factor, the temperature was increased most in 2014, which resulted in no precipitation that’s why it caused the extreme drought in 2014. Precipitation and NDVI values declined in years 2015 to 2019 in Mithi. A weak, moderate, and extreme droughts were recorded in 2012, 2016  and 2014, respectively. Satellite data provided promising results which were near to actual ground observations.