The Initial Investigation Of The Application Of Meshless Method In The Numerical Calculation Of Groundwater

The meshless method was a mathematical modeling methods which developd inthe1970s. This method had the advantages in the freedom of distribution and isremoved form the remeshing. So it had a good prospect of applocation in thenumerical calculation of groundwater in the pumping test and the details of theregional modeling.In this paper, we used the least squares method as the groundwater numericalcalculation. It was a high percision relatively and small computational grid method.Its discrete program was Galerkin collocation method, and its approximation schemewas the least squares method. We introduced the penalty function to the discrtion ofthe boundary condions in order to reflect the value of the boundary condions. Whendealing with unsteaty flow data, we needed to do difference calculation in the time.For introducing the meshless method to the numerical simulation of groundwater,we used it to calculate the movement of grounewater in the land between two riversand the Round Island pumping experiments. In the calculation of the land betweentwo rivers, we calculated the steady flow and the unsteady flow. In the unsteady flow,because of the water level was rising in the calculation, the method had the advantagebecause it didn’t need to remesh. During the calculation of the Round Island pumping,we discussed the impact of the different distribution programs, as well as the weightfuction of simulation results. The results proved using uneven distribution programs,as well as CSRBF weight function, you could get a more accurate numerical solution,and reduce the computation required to save calculation time.Compare the difference of the simulation results obtained by the meshlessmethod and the finite method. Through that, we could see through a reasonabledistribution of the nodes, the meshless method had the convenient in details portray,the freedom of distribution, and smaller calculation.We used the meshless method to inverse the parameter. The main data was theNabraska pumping test data. The method took account the pumping well pumping testdata in different distance into the calculation. The combination of different permeability coefficient and specific yield were substituted into the calculation usedthe validation to find the optimal results, the error rate was the minimum in which. Itprovided a new method to calculate parameter in groundwater. Then we used theJacob straight-line graphical method to verificate the result. The final results showedthe simular resulta botained by the two methods.That verify the feasibility.