两种土壤水分特征曲线间接推求方法对黄土的适应性评价

Evaluation of two indirect methods to estimate soil water characteristic curve of loess soil

土壤水分特征曲线(SWCC)是模拟土壤水分运动和溶质运移的一个重要参数,利用土壤的基本物理性质来间接推求SWCC的方法已经成为当今土壤物理学领域的研究热点。为了比较两种SWCC间接推求方法——Arya-Paris物理经验方法(简称AP方法)和Tyler-Wheatcraft分形几何方法(简称TW方法)对黄土的适应性,该文分析了黄土高原296组土壤颗粒分布、容重和水分特征曲线等资料,利用简化的Fredlund(Fred3P)模型模拟得到连续的土壤颗粒分布曲线,然后应用AP和TW方法预测出相应吸力下的土壤含水量。研究结果表明,对于黄土性土壤,AP和TW两种方法的预测结果均达到了一定的精度,相比较而言AP方法的预测效果明显优于TW方法,且受质地影响小。

Soil water characteristic curve （SWCC） is one of important parameters for modeling waterflow and solutes transport. The method used for soil basic physical properties to estimate SWCC has been a hot research field in soil science. For evaluating the adaptation of two indirect methods —Arya-Paris（AP）method and Tyler-Wheatcraft（TW） method —to estimate SWCC of loess soil, 296 soil samples with particle-size distribution were analyzed, bulk density and SWCC data on the Loess Plateau. A modified Frelund （Fred3P） model was used to simulate particle-size distribution, and AP and TW methods were used to predict SWCC of 296 soil samples. Results show that AP method has better precision for SWCC than TW method. At the same time, the soil texture has less effect on the prediction of AP model than TW method.