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土壤水分特征曲线是定量研究土壤水运动和溶质运移的重要参数,对滨海地区盐碱土绿化建设有重要的作用。通过对天津滨海盐碱地绿化土进行脱水试验,选取Gardner模型和VG模型对实测数据进行拟合。运用对数简化方法对Gardner模型变形后进行回归分析,另外,采用软件Matlab的非线性拟合函数lsqcurvefit对VG模型进行了参数求解。结果表明:Gardner模型和VG模型都可以用于天津滨海盐碱地绿化土水分特征曲线的拟合。Gardner模型的参数求解过程简单,但用VG模型计算出的残差平方和较Gardner模型小,拟合效果优于Gardner模型。同时,该区绿地土断面上各层之间的拟合曲线相近,持水能力相当,说明了该区绿化土断面上各土层的土壤质地和结构差异不大。
Soil water characteristic curve is an important parameter for quantitative study of soil water movement and solute transport, and plays an important role in saline-alkali soil afforestation in the coastal area. Through the dewatering experiments on the coastal soil in Tianjin coastal saline-alkali soil, the Gardner model and the VG model were selected to fit the measured data. The logarithmic reduction method was used to analyze the Gardner model after deformation. In addition, the nonlinear fit function lsqcurvefit of software Matlab was used to solve the VG model. The results show that both the Gardner model and the VG model can be used to fit the water characteristics curves of the coastal saline-alkali land in Tianjin. Gardner model parameters of the process of solving simple, but with the VG model calculated residual square sum smaller than the Gardner model, fitting better than the Gardner model. At the same time, the fitting curve of each layer on the green soil section in this area is similar, and the water holding capacity is quite similar, which shows that the soil texture and structure of each layer on the section of green soil in this area are not different.