根据瞬时剖面法的基本思想,提出一种利用剖面土壤含水率数据推求土壤水力参数的方法。可依据不同时间和深度的土壤含水率数据,得到土壤剖面不同深度处的土壤水分通量;根据van Genuchten模型描述的土壤负压及非饱和水力传导度与土壤含水率的关系,建立水分通量和土壤水分参数间的关系,并采用非线性最小二乘法估计最优土壤水力参数。文中应用软件HYDRUS-1D模拟12种土壤所得数据和田间尺度试验数据验证了方法的实用性。结果表明,该方法预测精度较高,可以方便地应用于均质土壤水力参数的估算。
An approach was presented to estimate the soil hydraulic parameters based on van Genuchten model and Darcy's law by using soil moisture data. According to the basic idea of the Instantaneous Pro- file Method, the soil hydraulic parameters were estimated by the Nonlinear Least Squares Methods using soil moisture data at different time and depths. The simulated soil moisture data of 12 kinds of soil provid- ed by software HYDRUS-ID, as well as the soil moisture data in a field-scale experiment, were applied to verify the reliability of this approach. The results show that the proposed method is of high precision, which can be used to estimate the hydraulic parameters of homogeneous soil.