Abstract: Due to high demand of water resources posed by rapid socio-economic development, the exploitation of groundwater depth experienced periods of critical overexploitation (2000 to 2006), intensifying overexploitation (2007 to 2011), and stable high overexploitation (2012 to 2015). Linear trend analysis of groundwater depth during the aforementioned three periods elucidated that the groundwater depth of all monitoring wells continued to decline. From 2000 to 2011, the drawdown of groundwater level in the study area accelerated in general, and from 2012 to 2015, the decline attenuated. The long-term overexploitation of groundwater had made groundwater depth in piedmont sloping plain declined by 4.10-12.67 m, and in alluvial plain declined by 9.07-22.26 m, threatening the natural ecology. Stepwise regression analysis showed that the groundwater depth was negatively correlated with runoff and positively correlated with groundwater exploitation, and both were the comprehensive reflection of groundwater recharge and discharge in the study area. The continuous drawdown of groundwater level was caused by the joint action of the reduction of groundwater recharge and the increase of groundwater exploitation intensity.

Key words: groundwater depth, high intensity of groundwater exploitation, linear trend analysis, runoff, exploitation amount, Korla