Study On The Model Of Groundwater And Land Subsidence In Haihe River Basin

Haihe River Basin is one of typical area areas in china which has Land Subsidence, this area lack water seriously and it mainly rely on exploitation of groundwater resources. During past 20 years, with acceleration of urbanization, rapid economic development, surface water pollution seriously, more and more buildings and the increasing demand for groundwater, the Haihe River Basin has become the area which groundwater overexploitation problem most seriously. Currently, Tianjin, Cangzhou and Beijing suburbs have become center of Land Subsidence in Haihe Basin.A methodology of modeling coupling to combine water allocation model and numerical groundwater model is put forward based on summary of current achievements of studies related to of surface-groundwater combination model. The coupling model is applied in Haihe River Basin to forecast the evolution of groundwater under different scenarios of water utilization and other changing boundary conditions. Method of data processing from output of water allocation mode to groundwater model is analyzed and designed based on data distribution on both spatial and time scale to solve the critical point of down scaling for model coupling. Interpolation is applied to transfer the results of water allocation on level year to time series for groundwater model. The simulation of groundwater evolution is initiated from the current status with the interpolated time series represented future water pumping and recharge. Application in Haihe River Basin verifies the feasibility of the coupling method.Haihe River Basin due to pumping underground water seriously, lead to clay soil overlying clay interlayer and release water, soil compression and land subsidence. Based on the data collection the Beijing area as the simulation of land subsidence, according to Beijing's actual engineering geology and hydrogeology conditions established geological conceptual model, and model boundary conditions, Haihe Plain in the original study, based on groundwater use Processing IBS Modflow and carry the package to the Beijing Plain aquifer water levels, land subsidence synchronized simulation parameters based on the information already established a model of land subsidence in the area, combined with the water resources of the different South scenarios, using the established model of land subsidence, predicted the future of the South of Beijing impact of land subsidence.The results of simulation in the plain areas of Haihe River Basin shows the deficit of groundwater will approach to 5 billion m3 without South-to-North Water Transfer Project (SNWTP) compared with only 1.4 billion m3 deficit if the Phase I of SNWTP is commenced in 2015. Meanwhile, the decline of groundwater table will be averagely 5-25m less if the SNWTP take effect although the water table continues declining. The trend of deteriorating groundwater environment will be totally relieved with the SNWTP, but more strategies and strict measures are still necessary to reach water balance of groundwater and healthy evolution.