高开采强度下库尔勒市地下水位埋深动态与影响因素浅析

库尔勒市社会经济快速发展对水资源的需求使其地下水开发经历了临界超采期(2000—2006年)、超采增长期(2007—2011年)和高位超采稳定期(2012—2015年)过程。为探究高开采强度下的地下水位埋深动态特征,以库尔勒市地下水监测网覆盖区作为研究区,对以上3个开采强度时段地下水位埋深进行线性趋势分析。所有监测井地下水位埋深均呈持续增大趋势,研究区2000—2011年地下水位埋深总体呈“加速”增大状态;2012—2015年转变为“减速”增大状态。地下水长期超采已使山前倾斜平原地下水位埋深累计增大4.10～12.67 m,冲积平原累计增大9.07～22.26 m,天然生态受到威胁。逐步回归分析表明,研究区监测井地下水位埋深与径流量呈负相关关系,与地下水开采量呈正相关关系,径流量、开采量实质是研究区地下水补给项与排泄项的综合反映。地下水位埋深持续增大是地下水补给量减少、地下水开采强度增大共同作用的结果。研究成果可为库尔勒市水资源开发利用与保护提供一定的参考。

Dynamics and Influence Factors of Groundwater Depth in Korla with Intensive Exploitation

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.