Spatio-Temporal Variations of Climate Variables and Extreme Indices over the Aral Sea Basin during 1960 - 2017

Abstract

The Aral Sea plays a key role in the socio-economic development of Central Asia. In the past few decades, with the combined effects of global warming and human activities, the ecological environment of the Aral Sea has undergone significant changes, such as the reduction of the basin area and the drop in water levels. In this study uses the observed climate data, combined with remote sensing to systematically analyze the characteristics of changes in climate in the Aral Sea Basin (ASB). We used linear regression, Pearson's correlation and Pettit's test to determine climate change. The main conclusions are as follows. Based on the analysis of the temporal and spatial changes of temperature, precipitation, and potential evapotranspiration in the Aral Sea Basin from 1960 to 2017, it was found that the annual average temperature, precipitation, and potential evapotranspiration increased by 0.32 ℃ decade-1, 0.16 mm decade-1, and 0.04 mm day-1 decade-1, respectively. In addition, the changes of these climatic variables were different in the growing season (April - September) and the non-growing season (October - March). Temperature and potential evapotranspiration increased in both growing and non-growing seasons; however, the precipitation decreased (increased) in the growing (non-growing) season. This means that the climate in the growing season showed a warming and drying trend. HIGHLIGHTS In this study, we present the complex and detailed analysis that we performed by combining temporal and spatial changes in key climate parameters temperature, precipitation and potential evapotranspiration and change of climate extreme indices in the entire Aral Sea Basin and its sub-regions. GRAPHICAL ABSTRACT