ABSTRACT

The Philip-Dunne falling-head infiltration for determining the parameters of soil water movement is a relatively simple procedure, yet the calculation is still complicated. This study develops a simplified method for determining soil saturated hydraulic conductivity k_s and Green-Ampt wetting front suction ψ. Field Philip-Dunne infiltration tests are performed in a loam soil under different initial head heights (30, 40, and 50 cm) at 45 test points. The relationship between infiltration time t_i and the parameters k_s and ψ is explored. The results show that Δθ within the range of 0.015–0.147 has little influence on k_s or ψ in the test soil, and prediction of the two parameters using mean Δθ meets the accuracy requirements. k_s is significantly negatively correlated with t_i and best predicted by 1/t_med; the prediction accuracy of the linear function is strongly influenced by the initial head height h₀. There is a significant relationship between ψ and t_max/t_med, and h₀ has little influence on the prediction accuracy of the power function. Therefore, the simplified models based on 1/t_med and t_max/t_med can be used for field-scale determination of the parameters k_s and ψ in loam soil, with an overall error below 10%.

抽象的

确定土壤水分运动参数的Philip-Dunne落头入渗法是一个相对简单的过程，但是计算仍然很复杂。本研究中开发用于确定土壤的简化方法饱和水力传导率ķ_小号和Green-Ampt入渗湿润前面吸入ψ。在不同初始水头高度（30、40和50 cm）下的45个测试点上，在一块壤土上进行了菲利普-邓恩野外渗透测试。浸润时间之间的关系吨_我和参数ķ_小号和ψ探索。结果表明，Δθ在0.015–0.147范围内对k _s影响很小或ψ在测试土壤中的应用，并且使用平均值Δθ预测两个参数符合精度要求。k _s与t _i呈显着负相关，最好用1 / t _med预测; 线性函数的预测精度受初始磁头高度h _0的强烈影响。ψ与t _max / t _med之间存在显着关系，并且h ₀对幂函数的预测精度影响很小。因此，基于1 / t _med和t _max /的简化模型吨_配有可用于该参数的字段比例确定ķ_小号和ψ在壤土，具有低于10％的总误差。