【摘要】 借助于最小二乘法,形成了确定Brooks-Corey(1964)模型,van Genuchen(1980)模型中的参数所对应的非线性方程组,并用Picard迭代求解它们。用VB语言编写了程序,用压力膜法测定了潮棕壤土同一地点不同层的水分特征曲线。最后,用以上两种模型对土壤水分特性曲线进行了预测,结果表明:VG模型与BC模型的预测值均与实测值具有良好的一致性,VG模型较BC模型对潮棕壤土土壤水分特征曲线的预测效果更好些。更多还原

【Abstract】 Soil water characteristic curve refers to the relationship between volumetric water content and pressure head,which plays a very important role in solving the problems of water flow and solute transport in soil.Due to its complexity,it is difficult to derive an accurate equation in theory.However,quite a number of experience formulas have ever been proposed on the basis of a number of experiment,such as Brooks-Corey(1964) model,van Genuchten(1980) model etc.,in which many parameters need to be determined.In this paper,by means of the least square method,the nonlinear equation groups that were used to obtain the parameters in models above mentioned were derived,and their Picard iterative forms were gotten.The algorithm was coded by means of the Visual Basic.Soil water characteristic curve that was obtained from the different floor soil was measured with the method of soil moisture pressure membrane.Compared with soil water characteristic curves,it was found that the predicted soil water retention curve agreed well with the measured data,and the result from van Genuchten model was better than Brooks-Corey model.更多还原