Evaluation On Groundwater Boundary Exchange Capacity Of Strong Open Boundary Aquifer

Open boundary means having good permeability and can exchange material, energy and information with the external environment. The groundwater systems which have no natural boundaries and regional watershed, their artificial boundary mostly are open boundary. Strong open boundary refers to open boundary which can exchange large-scale material, energy and information with the external environment. Aquifer boundary exchange capacity refers to an aquifer and the external environment through its border exchange activities to get net water in a period of time.Erlongtao irrigation area is located in the cold region and it has typical open characteristics boundary, put it as the study area and investigate and analysis the boundary characteristics in the study area. Meanwhile, carding and analysis routine border exchange capacity evaluation methods. On this basis, selecting groundwater dynamics method, water balance method and numerical iterative method for calculating the amount calculated boundary exchange. Finally, evaluating and combing border exchange capacity calculation methods, discussing the parameters involved in the calculations.The results showed that groundwater dynamics method and water balance method are fit for calculating large area, low computational accuracy required area. Based on numerical iterative method is fit for the study area of calculating high precision and having adequate basis data. Parameter determines aspects, groundwater dynamics method and iterative method based on numerical calculation is mainly to identify the direction of groundwater flow, groundwater levels and other parameters. Water balance method is mainly to identify isostatic periods and equilibrium elements. Aspects of the calculation results, the accuracy of groundwater dynamics calculation method and water balance method are slightly lower than the numerical iterative method. The core of the three methods are darcy formula, if we can control the parameter accuracy through field experiment and setting reasonable monitoring well, groundwater dynamics method will have general applicability.