基于van Genuchten模型土壤水分特征曲线的vanfit和MATLAB软件模拟研究

Simulation of Soil Moisture Characteristic Curve Based on van Genuchten Model by vanfit and MATLAB Software

研究了土壤水分特征曲线对探讨土壤水分运动机理及溶质运移动力学机制具有重要科学意义。由于测定土壤水分特征曲线的长历时性和时间限制,在从相关参考文献中提取土壤水分特征曲线测定数据的基础上,建立土壤水分特征曲线的资料库,采用van Genuchten模型对土壤水分特征曲线进行描述,分别应用vanfit软件和MATLAB软件下的lsqcurvefit函数2种方法对土壤进行van Genuchten模型下的4个参数拟合分析。结果表明,2个程序拟合结果大体相近且优良,均方差较小,拟合曲线大致相同,且土壤质地不同,其土壤水分特征曲线差别较大。

The study of soil water characteristic curve is of great scientific significance for the discussion of soil water movement mechanism and solute transport mechanics mechanism.Due to the long duration and time limit of measuring the soil moisture characteristic curve,established a database of soil moisture characteristic curve on the basis of extracting the measured data of soil moisture characteristic curve from relevant references,and used van Genuchten model to describe the soil moisture characteristic curve,The four parameters of the van Genuchten model were fitted and analyzed by using the two methods of vanfit software and lsqcurvefit function under MATLAB software.The results showed that the fitting results of the two programs were generally similar and excellent,and the mean square deviation was also very small.The fitting curves were basically the same.It is found that the soil moisture characteristic curves vary greatly with different soil textures.