Mechanism of Groundwater Recharge Increment Induced by Urbanization
城市化诱发地下水补给增量的机理分析

The study on impact of urbanization on groundwater recharge has a very important significance, not only for studying the hydrologic cycle, supply-demand balance, groundwater overexploitation, but also for preventing and controlling the deterioration of groundwater quality, and for revealing the organic relation between overexploitation and water quality deterioration, the two main problems of groundwater environment. However, up to now, it has not been determined weather the urbanization development would result in the increase or decrease of groundwater recharge, and the impact mechanism of urbanization on groundwater recharge also has not been illustrated. The study on the interaction mechanism of urbanization and groundwater in Shijiazhuang City is a typical example. In this paper, based on the analysis of the importance of groundwater in water supply of the city, and the exploitation and utilization of groundwater, the authors studied the change of groundwater recharge under the impact of urbanization, and further discussed the impact mechanism of urbanization on groundwater recharge. Finally, a frame-figure on the mechanism inducing the increment of groundwater recharge was constructed. The results show: 1) urbanization results in the increase of groundwater recharge; 2) the inducing of groundwater from the well-field around city and surface water by exploitation of groundwater, and the importing of new recharge sources resulting from the leakage of water-supply and water-discharge systems of city, is the important mechanism inducing the recharge increase of groundwater by urbanization; 3) the new recharge sources resulting from the leakage of water-supply and water-discharge systems are one of the important components which should be considered fully in the calculation of groundwater recharge in the urban districts. This study supplies a kind of theory and new approach to study hydrological cycle and water resources in the urban districts.