Construction And Application Of Numerical Model Of Groundwater Flow In Large-scale Area

Groundwater numerical simulation technology has been an essential tool to reveal the movement of groundwater and evaluation of water resources. With the development of the socio-economic, the broadening of the hydrogeological research field and the regionalization of groundwater resources, groundwater flow numerical simulation in large-scale area has become an important direction for numerical simulation technology gradually. Groundwater is the main water resources in North China Plain which facing water shortages and many environmental geology problems. Therefore, it is necessary to establish groundwater flow numerical models in North China Plain, which could not only improve regional modeling technology, but also take advantage of large regional models to evaluate the groundwater resources of North China Plain accurately, which could provide a scientific basis for utilizing water resources reasonably.In this paper, it established the groundwater flow numerical model of the North China Plain by using the regional groundwater numerical simulation techniques. The simulation period of regional model was 10 years. The regional model used the data from 2002 to 2003, analyzed the data of sources and sinks with GIS and interpolation, and then used GMS to obtain the groundwater flow field ofNorth China Plain in 2011. By the inversion of the groundwater exploitation, the fitting of the flow field and the line fitting of water level, the model calculaton results were consistent with the actual hydrogeological conditions, and then the model analyzed the water budget. Finally it evaluated the resources of groundwater and predicted the level of groundwater when the North Water Diversion Project began.It showed the recharge of shallow groundwater aquifer was 256.77×108 m3/a, the mineable resources of shallow groundwater aquifer was 194.58×108m3/a, and the mineable resources of deep groundwater aquifers was 27.75x108m3/a in North China Plain by using the final results of the groundwater exploitation and analyzing the simulation of water budget in large-scale area.The model predicted the groundwater level changes in North China Plain, which forecasting period was 19 years and groundwater exploitation was compressed according to the plan of North Water Diversion Project. The results of regional model simulation showed that after the North Water Diversion Project, in 2030, the shallow groundwater level of North China Plain would rise apparently, the center water level of deep groundwater cone would rise, and the area of deep groundwater cone would reduce, but the recovery rate of groundwater level was slowly in some areas. In North China Plain, the total recharge of groundwater was 252.85×108m3/a, the total discharge of groundwater was 268.11 x108m3/a, and the difference between recharge and discharge of groundwater was-15.27xl08m3/a. After the North Water Diversion Project, the groundwater of North China Plain was still in the overexploitation state generally, but the difference between recharge and discharge of groundwater was smaller than not to supply, which illustrated that the North Water Diversion Project would ease the overexploitation of groundwater to a certain extent.