筛分直径和容重影响条件下土壤水分运动参数变化特征研究

Research on Soil Water Movement Parameter Variation Characteristics under the Influence of Sieving Diameter and Bulk Density

本文采用Ku-pF非饱和导水率测定系统测定不同筛分直径、不同容重条件下土壤水分特征曲线,并在此基础上套用非线性最小二乘法函数Lsqcurvefit和Van Genuchten公式,在MATLAB软件中拟合实测数据,得到拟合曲线及土壤水分运动参数,并对其变化特征进行分析,以期揭示出土壤水分运动参数在不同筛分直径、不同容重条件下的变化特征。结果显示,在研究土壤水分运动参数的变化特征过程中,介质的筛分直径和容重均起着不可忽视的作用。因此在研究土壤水分运动机理和评价土壤水资源时,要科学适宜地选择土壤水分运动参数。

In this paper,a Ku-pf unsaturated hydraulic conductivity measurement system was used to measure soil water characteristic curves under different screening diameters and bulk densities.On this basis,the nonlinear least square method functions lsqcurvefit and van were applied Genuchten formula was used to fit the measured data in MATLAB software,and the fitting curve and soil water movement parameters were obtained,and their change characteristics were analyzed in order to reveal the change characteristics of soil water movement parameters under different screening diameters and bulk densities.The results show that the sieving diameters and bulk densities of soil medium can not be ignored in the study of the change characteristics of soil water movement parameters.Therefore,when studying the mechanism of soil water movement and evaluating soil water resources,we should scientifically and appropriately select soil water movement parameters.