Assessment of human-induced environmental disaster in the Aral Sea using Landsat satellite images

The Aral Sea was the fourth largest lake in the world before 1960. Reduction of water resources and the growth of water intake and reservoirs in the source rivers have severely desiccated the Aral Sea. This study aimed to model the spatiotemporal and surface temperature changes of the Aral Sea in the period 1986–2017 using the Landsat multi-temporal satellite data and remote sensing techniques. Since the desiccation period was accompanied by climate change, hydrological data of source rivers, as well as climate data were collected from meteorological stations near the Aral Sea, to study the causes of changes. To achieve the research objectives, the Normalized Difference Water Index (NDWI) was selected among the other indices to extract and quantify the water area changes. Land and water surface temperature values were calculated using the thermal bands to examine the surface temperature change, which has rarely been discussed in the literature. The results revealed a significant decrease in the Aral Sea surface area (~ 78%) and a considerable increase in the land surface summertime temperature (~ 12 °C). The statistical results showed that the Aral Sea water extent decreased from 44,164 km2 in 1986 to 9772 km2 in 2017.