Dynamics of human-induced lakes and their impact on land surface temperature in Toshka Depression, Western Desert, Egypt

Changes in land-use/land-cover (LULC) give rise to several environmental problems which modify the microclimate of a region. Therefore, land surface temperature (LST) is a significant environmental variable that is appreciably influenced by LULC changes. The main aim of this research was to quantify the impacts of LULC changes from the drying of Toshka Lakes on LST by remote sensing and geographic information system (GIS) techniques. Landsat series Thematic Mapper (TM) and Operational Land Imager (OLI) satellite images were used to estimate LST from 2001 to 2019. Automated Water Extraction Index (AWEI) was applied to the mosaicked Landsat images to extract water bodies from the research area. Optimized Soil-Adjusted Vegetation Index (OSAVI) was utilized to predict the reclaimed land in the Toshka region until 2019. The kappa coefficient had been involved in this research to assess the accuracy of water extraction. The results indicated a decrease in the lakes by about 1517.79 km2 with an average increase in LST by about 25.02 °C from 2001 to 2019. It was observed that the dried areas of the lakes were converted to bare soil and are covered by salt crusts. The results indicated that the land-use change was a significant driver for the increased LST. The mean annual LST increased considerably by 0.6 °C/year from 2009 to 2019. A strong negative correlation between LST and Toshka Lakes area (R-square = 0.98) estimated from regression analysis implied that Toshka Lakes drying considerably affected the microclimate of the study area. Severe drought conditions, soil degradation, and many environmental issues were predicted due to the rise of LST in the research area. The findings of this research focus on the benefits of satellite data for assessing human-induced changes and their impacts on microclimate. There is an urgent need to develop favorable strategies for sustainable environmental management in the Toshka region.