Groundwater Three-dimensional Numerical Simulation Of Tianjin

Water resources are extremely scarce in Tianjin . Groundwater has brought about long-term groundwater overexploitation. Many environmental-geological problems occur, such as land subsidence, seawater intrusion etc. From the view of sustaining development,the shortage of water resources has become the main controlling factor that restricts the development of economy and society in Tianjin. So it is necessary to evaluate groundwater resources in Tianjin area more exactly for sustaining use of groundwater.In this dissertation, the groundwater numerical modeling is applied to study on groundwater resources evaluation of Tianjin. Based on the tianjin area, the groundwater numerical modeling is established. The study area is about 11190km2. The groundwater modeling system Visual modflow, which makes the best of borehole data according to transition probability approach and carries through geologic simulation based on conditional simulation of geo-statistics, is applied to construct the hydro geologic structure model, the condition of replenishment and drainage can be identified further. Then the hydro geologic conceptual model is developed and the regional mass of data of sources and sinks are assigned by GIS, data basement and outside files of Visual modflow. At last, the hydrogeology-unit constructs the groundwater numerical simulation model, while the parameters are defined by the materials, the model must be verified its accuracy and reliability.Based on the analysis of groundwater supply and demand after South to North diversion scheme in 2010a, predication of ceasing exploitation of groundwater 18286.7×104m3/a and 30478×104m3/a is made through the developed numeric simulation model. In the study area, the excess exploitation decrease evidently and the exploitation maintains the level of safe yield in an extent and the water lever at the central of the cone of depression in unconfined and confined aquifer rise by 9~18m and20~30m after ten yeas of ceasing exploitation scheme carrying out. In a summary, the midline of South to North can improve the situation of the excess exploitation, and have significant effect on groundwater lever recovery of Tianjin.