Van Genuchten模型参数对降水入渗数值模拟的敏感性

发布时间：2018-02-17 02:45

本文关键词： van Genuchten模型参数敏感性分析降水入渗数值模拟 HYDRUS 水文地质　出处：《地球科学》2017年03期 　论文类型：期刊论文

【摘要】：详细分析不同评价指标下的van Genuchten方程参数敏感性,对于深入认识参数物理意义、合理确定参数值、提高降水入渗数值模拟准确性具有重要意义.用HYDRUS软件建立一维变饱和水分运移模型,以实际补给量、补给过程曲线和极限蒸发深度作为评价指标,采用单因素扰动分析法对van Genuchten方程各参数敏感性进行理论分析,进而选取多组参数实例,分析同一岩性类别下,不同土样土壤水力参数差异及其对入渗补给模拟结果的影响.结果表明:形状系数(n)、土壤进气值的倒数(α)与极限蒸发深度呈负相关关系,是影响极限蒸发深度的显著因素;饱和含水率(θs)、n、饱和渗透系数(Ks)对于入渗补给影响的敏感性较高,三者在实际土样粒径分布、干密度和孔隙性的共同影响下发生同向变动.合理的参数敏感性分析及数值模拟调参过程需结合土壤参数的物理意义来开展.
[Abstract]:The parameter sensitivity of van Genuchten equation under different evaluation indexes is analyzed in detail. It is of great significance to improve the accuracy of numerical simulation of precipitation infiltration. A one-dimensional variable saturated water transport model is established by using HYDRUS software. The actual replenishment, recharge process curve and limit evaporation depth are taken as evaluation indexes. The sensitivity of each parameter of van Genuchten equation is theoretically analyzed by using single factor perturbation analysis method, and then a number of parameter examples are selected to analyze the sensitivity of each parameter in the same lithologic category. The difference of soil hydraulic parameters in different soil samples and its influence on the simulation results of infiltration and recharge. The results show that the reciprocal (伪) of soil intake value is negatively related to the limit evaporation depth, and is a significant factor affecting the limit evaporation depth. The saturated water content (胃 sn) is highly sensitive to the effect of infiltration recharge. Due to the influence of dry density and porosity, reasonable parameter sensitivity analysis and numerical simulation should be carried out in combination with the physical meaning of soil parameters.
【作者单位】：长江大学资源与环境学院;中国地质大学盆地水文过程与湿地生态恢复学术创新基地;中国地质大学环境学院;
【基金】：国家自然科学基金项目(Nos.U1403282,41602246)
【分类号】：P641.2

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