南小河沟流域土壤水力特性参数的试验研究及特征分析

Experimental study and characteristic analysis of soil water characteristic curve in Nanxiaohegou basin

【目的】研究土壤水力特性参数及其特征,为土壤水力特性参数的选取和确定及水分运动和污染物迁移的预测奠定基础。【方法】对甘肃省南小河沟流域不同地貌、不同土地利用方式的土壤进行分层取样,采用离心机法测定各地类的土壤水分特征曲线,运用Gardner模型对试验结果进行分析。【结果】Gardner模型的对数形式能较好地反映各地类的土壤水分特征曲线。对全流域及划分地类后得到的模型参数的关系分析表明,它们具有较好的线性关系,因此可将模型进一步简化为单一参数模型。对单一参数模型参数统计特征的分析表明,单一参数A随着地貌类型的变化而表现出一定的变化特征,可以作为土壤水分特征曲线空间变异的变异系数。【结论】可以用参数A作为反映地貌类型的指标,并可应用于区域土壤水分特征曲线的估计。

[Objective] To study soil hydraulic properties parameters and fractal characteristic can lay a foundation for the selection and identification of soil hydraulic properties parameters, as well as for soil water movement and prediction of pollutants transport. [Method] Soil water characteristic curves of 56 soil samples from different land uses were obtained in Nanxiaohegou basin by field and inside experiments. [Resuit] And the curve shape fitted in with use of Gardner logarithmic model,powerful model and exponential model at the same time, the entire model fitted well and the logarithmic model was the best. Further analsis of the relationship of the Gardner logarithmic model coefficient and constant showed that all the coefficients and constants of the different landform types were of linear relationship. [Conclusion] So, the Gardner logarithmic model can be established to characterize the soil water characteristic curve of the Nanxiaohegou basin.