Coupling Numerical Simulation Between Groundwater Exploitation's 3D Seepage Field And Subsidence Of Developing Belt Along Yangtze River In Jiangsu Provence

With the development of the national economy, the land subsidence of geological disaster becomes worse because of excessive pumping groundwater. Under the pressure of the urgent circumstances, the new demand from evaluation and management of the groundwater has been put forward that the evaluation of the groundwater must be combined with subsidence for controlling the subsidence to the greatest extent while getting the maximum quantity of groundwater resources.The quaternary-loose-pore aquifer in developing belt along Yangtze River at Jiangsu Province is studied. A coupling model between 3D groundwater seepage and subsidence is built. By using finite-difference approach, the coupling model is simulated numerically. After modifying and calibrating the numerical model, dynamic changes of groundwater head and subsidence are assessed. All conclusions we sum up in the paper provide scientific reference for the reasonable evaluation of groundwater resources and efficient control of subsidence development for the belt. The main contents are as follows:Firstly, the geologic, hydro-geologic and engineering geologic conditions of the belt are analyzed systemically. After summarizing the hydro-geologic feature and the mechanism of subsidence development, a conceptual model between groundwater and subsidence is built.Secondly, a coupling model between 3D seepage field of groundwater exploitation and subsidence is set up. With the finite-difference approach, the coupling model is simulated numerically and a computer program is written.Thirdly, by using observation borehole datum from January 1, 2003 to December 31, 2003, the hydro-geologic parameters are identified and calibrated. With the method of analogy, the parameters of subsidence are confirmed. Then a visualized computer model is built by calculation program according to the geological condition.Finally, the changes of the hydraulic head and land subsidence for the next ten years are predicted with the existing exploitation's scheme. Aiming at the problem of the excessive subsidence with the existing exploitation scheme, an exploitation project is put forward on the condition of controlling land subsidence possibly which is exploited with the existing exploitation's scheme by adjusting exploitation layout.