Analytic Solutions’ Performance Of The Model With Seepage Flow And Parameters Sensitivity Analysis

The study of hydrogeological parameters has great siginficance to groundwater resources evaluation and the reasonable planning, using and mining of groundwater.Analytical method is the most basic and important in the groundwater system research. To study the analytical solutions of groundwater model equation formula and parameters’ sensitivity is very necessary and significant.This Thesis analyze the performance of analytical solutions of groundwater seepage model by calculating its condition number, and compare the advantages and disadvantages of various sensitivity analysis methods. With the method of finite difference method and perturbation analysis method has the characteristics of simple and clear principle, it’s calculation is relatively simple, were applied to the seepage model of first kind of leakage recharge unsteady flow and anisotropy aquifer to corresponding calculate the local sensitivity of parameters. At the same time, Morris, a relatively small amount of calculation, principle is relatively simple in the global sensitivity method, is applied to the model of groundwater. The method is applied to calculate the sensitivity of the parameters of the first kind of leakage recharge unsteady flow and anisotropy aquifer model. The research works mainly in the following aspects:1、First of all,random variable of error calculation of the function are expounde d. The relationship between variance and variable variance in the analytical solution formula is derived in the first kind of leakage recharge unsteady flow system and anisotropy aquifer system.2、Introducing the concept of condition number and using mathematical method to deduced the first kind of leakage recharge unsteady-flow and anisotropy aquifer model with the equations analytical solution formula of the condition number; Setting up the relationship between positive and inverse problem calculation error and contains parameters’ error. According to the concept of condition number respectively to the two analytical solution formula of performance, then obtain the analytical solution of the formula "bad" and "good" condition to determine the reasonableapplication.3、With the introduction of various sensitivity analytical method, combining with the advantages and disadvantages of various methods, combining the finite difference method and system perturbation method of the local sensitivity analysis method, then applying them to the groundwater model to calculate the parameters’ partial sensitivity of the firstkind of leakage recharge unsteady flow and anisotropy aquifer of the model equation.4、Method of Morris from the global sensitivity analysis method is introduced into the groundwater system, and the matrix of Morris conducted a randomized to make the result more reasonable. Discussing the parameters’ global sensitivity of he first kind of leakage recharge unsteady flow system and the anisotropy aquifer system. By comparing local and global sensitivity, the influence of the relationship between parameters became unequivocal. Method of Morris was applied to calculate the interaction among various parameters. By comparing, the conclusion of the two kinds of analysis is consistent. Then,obtaining aquifer parameters of the two kinds of model equation is more sensitive.5、Comparing the calculation results of parameters’ sensitivity. It is concluded that the global sensitivity due to considering the interaction between the parameters, so the global sensitivity is more accurate and reliable than local sensitivity.