Parametric Estimation of the Van Genuchten’s Equation by the Optimization Method

According to the principle of simplex evolutionary method, the Van Genuchten's Equation (VGE) of the curves which are used to describe the feature of soil water movement are fitted.The method can be used to estimate the parameters of the VGE's curves which describe the feature of water movement of different matrixes' soil, and the fitt ing error is very small.The algorithm is coded by means of the Visual Basic.The program provides many different kinds of data in and data out formats which now are used frequently, has friendly man machine interface, and is easy to use.