Groundwater Dynamic Drift and Response to Different Exploitation in the North China Plain: A Case Study of Luancheng County, Hebei Province
华北平原地下水动态及其对不同开采量响应的计算——以河北省栾城县为例

The groundwater table has been declining at a rate of 0.65 m/yr in Luancheng County since pumping groundwater on a large scale in the 1960s. The decrease of the precipitation, large increase of the agricultural output, variation of the crop growing structure and the building of the hydraulic project in the headwater area all tie up with the decline of the groundwater table. On the basis of analyzing the hydrogeological condition and the water resources utilization of Luancheng County, we build a three-dimensional groundwater flow model, and simulate the groundwater flow through finite-difference method using Visual Modflow software. We divide the research field into four parts after analyzing the hydrogeological condition. After calibrating and adjusting parameters using measured data, we simulate the parameters of hydraulic conductivity and specific yield. Using the calibrated model, this article analyzes the agricultural water saving potentiality and its influence on the groundwater. The results are as follows: (1) if we decrease the pumping water by 0.14×108 m3, the average groundwater table of five observation wells in December will rise by 0.33 m; (2) if we decrease the pumping water by 0.29×108 m3, the average groundwater table of five observation wells in December will rise by 0.64 m; (3) if we increase the pumping water for 0.29×108 m3, the average groundwater table of five observation wells in December will decline by 0.45 m. So we can draw a conclusion that controlling the agricultural water use is an important way to prevent the groundwater table's decline.