“三滩”傍河水源地地下水水位降落漏斗区水质演化

An analysis of groundwater quality evolution in the area of depression cone in the Santan riverside wellfield

本文在1987～2006年兰州断陷盆地典型水源地地下水环境监测资料基础上,通过2007年10月环境地质补充调查采集地下水样品11组、地表水1组,综合分析了断陷盆地地下水集中开采区浅层地下水水化学特征及时空分布规律,以及黄河条带状为补给区的地下水与开采降落漏斗的水质演变关系。根据多年开采过程中地下水水化学成分的变化及影响因素,阐明了水化学组分与地下水位的密切关系;利用开采量水质时空变化对比资料,得出地下水位下降排泄区与傍河区地下水存在的水力联系。依据本次环境地质调查结果和水样实测数据,进一步论证了傍河区地下水受黄河激发补给因素控制的结论。

The hydrochmical characteristics and the spatial and temporal distribution of water chemistry in the shallow groundwater in the Lanzhou faulted - depression basin were examined in this paper. The study focused on the exploitation of groundwater in shallow groundwater areas and analyzed the relationship of the Yellow River for groundwater recharge and water quality of the exploitation of the evolution of the land funnel. A typical rift basin water monitoring data for many years （1987 -2006） of groundwater a recent investigation of the geological environment and groundwater was used and the surface water sampling test results were included. Based on the chemical compositions of water samples and the impact factors of multi - year exploitation of groundwater, the chemical compositions of water was found to be closely related to the water table. Comparison of spatial and temporal changes in the exploitation with water quality data and analysis of groundwater level decline in discharge areas along the riverside area conform the existence of a hydraulic connection. Based on a geological environment survey and analyses of water samples, this research further came to the conclusions that the riverside wellfield is controlled by the induced recharge from the Yellow River.