Drought analysis of Van Lake Basin with remote sensing and GIS technologies

Drought is defined as the amount of precipitation in a region less than the amount of evaporation. Human facts such as population growth, industrialization, deforestation, and uncontrolled irrigation in agriculture are among the factors that cause drought. Today, with the increase of human activities such as population growth and industrialization, drought has become a serious life-threatening issue. With a depth of around 450 m and a volume of over 600 km³, Lake Van (Turkey) is the world's largest soda lake and one of the world's largest closed-basin lakes. Increasing temperatures and decreasing precipitation in recent years indicate that there may be a drought in Lake Ban. It is important to analyze this drought and determine its change. Methods derived from remote sensing and geographic information systems technologies provide speed, practicality, and high accuracy in determining drought. Research to date has not yet determined the change of drought in Van Lake Basin using remote sensing and GIS methods. In this study, the drought in Van Lake Basin was examined periodically from 1989 to 2019. In this context, Land Surface Temperatures (LST) and Land Use/Land Cover (LULC) maps of the basin were obtained from Landsat-5 and Landsat-8 satellite images. In addition to remote sensing and GIS analysis, the Standard Precipitation Index (SPI) was calculated with precipitation data obtained from meteorology stations to determine the drought in the region. According to the results, it was concluded that the drought level in the basin has been increasing from 1989 to 2019. The findings of this research provide insights for drought increase in Van Lake Basin. Also, this study strengthens the idea that remote sensing and GIS methods can be used in drought studies effectively.