Simultaneous estimation of the soil hydraulic conductivity and the van Genuchten water retention parameters from an upward infiltration experiment
Simultaneous estimation of the soil hydraulic conductivity and the van Genuchten water retention parameters from an upward infiltration experiment
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DOI：
10.1016/j.jhydrol.2019.03.011
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发表时间：
2019-05
影响因子：
6.4
通讯作者：
B. Latorre;D. Moret‐Fernández
中科院分区：
文献类型：
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作者：
B. Latorre;D. Moret‐Fernández
本文提出了一种新的实验室方法，通过对5厘米高土柱的向上入渗曲线的反分析，同时估计van Genuchten (1980)θ(h)的ksand α和参数。对理论壤土、壤土和粘性土合成的一维入渗曲线进行了评价。研究了土壤初始条件对逆分析的影响。其次，提出了一种优化方法，并在8种理论土壤（从壤土到粘土）上进行了试验。随后将该方法应用于五种筛过的土壤（从沙子到粘土）的实验曲线，这些土壤被装入5厘米高和直径的圆柱体中。将实验曲线反分析所得的TheKs、α和n值与Darcy法和压力电池法（PC）的测量结果进行比较。初始土壤张力hi固定为−6.0·105cm，对优化有重要影响。该优化方法具有鲁棒性，可以准确估计实际水力参数。理论k值、α值、α值与逆分析得到的相应值之间的关系接近于1 （R2= 0.99）。对于试验土，反演计算的ksandn （R2> 0.98）与Darcy和PC测量的ksandn （R2> 0.98）之间的关系接近于1。α与偏离1的斜率关系不显著。
This paper presents a new laboratory method to simultaneously estimateKsandαandnparameters of the van Genuchten (1980)θ(h) from the inverse analysis of an upward infiltration curve measured in a 5-cm high soil column. The method was evaluated on synthetic 1D infiltration curves generated for a theoretical loamy sand, loam and clay soil. The influence of the soil initial condition on the inverse analysis was also studied. Next, an optimization method was presented and tested on eight theoretical soils (from loamy sand to clay). The method was subsequently applied to experimental curves measured on five sieved soils (from sand to clay) packed in 5-cm high and diameter cylinders. TheKs,αandnvalues estimated from the inverse analysis of the experimental curves were compared to those measured by Darcy and the pressure cell method (PC). The initial soil tension,hi, which had an important influence on the optimization, was fixed to −6.0·105cm. The optimization method resulted robust and allowed accurate estimates of the actual hydraulic parameters. A close to one relationship (R2= 0.99) was observed between the theoreticalKs,αandnand the corresponding values obtained with the inverse analysis. Regarding to the experimental soils, significant relationships close to one were obtained betweenKsandn(R2> 0.98) estimated from inverse analysis and those measured with Darcy and PC. A non-significant relationship with slope away from one was found forα.