Influence of Aral Sea Area Shrinkage on Regional Land Surface Temperature

  Objectives  Water body plays an extremely important role in regional climate regulation. In recent decades, due to the unreasonable utilization and intensive development of the Aral Sea water resources by human beings, the water level and area of the Aral Sea have experienced a sharp decline and shrinkage, which inevitably has an important impact on the regional climate of the Aral Sea. So analyzing the changes of surface temperature variation in the Aral Sea region is of great significance for studying the relationship between the water body and the regional surface temperature.

  Methods  In order to reveal the variation characteristics of surface temperature affected by the Aral Sea, the MODIS(moderate-resolution imaging spectroradiometer) surface temperature product (MOD11A2) in the Aral Sea area from 2000 to 2015 is used to analyze the affection on the regional surface temperature based on spatial analysis method. Firstly, the trend line analysis method is used to analyze the change trend of surface temperature in the Aral Sea and its surrounding areas from 2000 to 2015, so as to identify the approximate range of surface temperature affected. Secondly, the characteristics of surface temperaturechange with the increase of the distance from the Aral Sea are clarified by using the buffer zone analysis method and section line analysis method. Finally, based on the land use data, the change trend of surface temperature of the main land types in the Aral Sea is analyzed.

  Results  Compared with the surface temperature of the Aral Sea, the surface temperature of 93% and 69% of the study area shows an upward trend respectively in the daytime and the nighttime during the study period from 2000 to 2015.The direct impact range that the Aral Sea on the regional surface temperature is roughly within 30 km along the lake boundary. As the area of the Aral Sea shrinks rapidly, the surface temperature difference between the various land cover types and the Aral Sea shows an increasing change trend.

  Conclusions  Large lakes similar to the Aral Sea have obvious temperature regulating effect on the regional environment. The reduction of the Aral Sea area has significantly reduced its temperature regulation function.The impact of the Aral Sea area change on regional climate plays an important warning role in the protection and management of wetlands and lakes.