The Study On Numerical Simulation Of Groundwater Recharge At A Demonstration Site Of Gao Cheng City

Due to the excessive exploitation of groundwater resources in the North China Plain, groundwater resources are facing shortages and ecological environment deterioration, therefore how to plan and utilize water resources, and increase the storage capacity of groundwater resources become the focus of research questions. The technology of artificial recharge of groundwater can recharge surface water into the underground aquifers, making groundwater resources getting supplementary. The paper chooses the artificial recharge test site, which is placed in Liyuan Village, Gaocheng City, as the study area, analyzing the effect of artificial recharge of groundwater and recharge effectiveness.Based on the thesis analysis of the test site’s geological and hydrogeologic features, using the datas from 2013 to 2014 by GMS software, the groundwater simulation model was constructed. By fitting drilling water line process, hydrogeological parameters of the model were analyzed and identified. And based on the test datas for groundwater recharge, the model is further validated. The results show the model meets accuracy requirements, basically reflecting the hydraulic characteristics of the groundwater flow system, and groundwater budget of study area were analyzed, which thereby provide reasonable parameters for the prediction model.On the basis of the flow model, the groundwater recharge numerical model was established. And based on the number of recharge wells, the programs of single well and two multi-well joint recharge were designed, then the effect of these two programs were analyzed and compared. The results show that the use of artificial groundwater recharge, enables that the storage of groundwater resources were not effectively restored possible, and did not result in better resource efficiency. That is mainly because the scope of study area is small, the closure is not good enough, and the lateral outflow is too large.Compared to the program without recharg, for option one at the end of the recharge, the scope of water level amplitude at 0.1m above is 0.54km2 in the unconfined aquifer, and maximum groundwater level rises by 5.2m; for option two at the end of the recharge, the scope of water level amplitude at 0.1m above is 0.38km2 in the unconfined aquifer, and maximum groundwater level rises by 1.3m. Option two compared to option one, the overall water level rise are relatively small.On the basis of option one, a site solute transport model was constructed about TDS, total hardness and nitrite nitrogen for a period of one year, and the change and distribution of the three indicators were analyzed in one year. The results show, on the whole, the concentration of the recharge solute higher than local concentration(nitrite nitrogen) decreased as the solute transport in groundwater systems, by advection and hydrodynamic dispersion; the recharge solute less than local concentration(TDS and total hardness) reduced the corresponding concentrations of the immediate area as the solute transport in groundwater systems by a variety of groundwater system actions.