基于HYDRUS-1D模拟的变水头入渗条件下VG模型参数敏感性分析  

Parameter sensitivity analysis of VG model in the varying-head infiltration based on HYDRUS-1D simulation

作　　者：张海阔[1] 姜翠玲[1] 李亮[2] 朱立琴[3] ZHANG Haikuo;JIANG Cuiling;LI Liang;ZHU Liqin(College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China;Huaian City Water Conservancy Survey and Design Institute Co.,Ltd.,Huaian 223005,China;School of Marxism,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源学院,江苏南京210098 [2]淮安市水利勘测设计研究院有限公司,江苏淮安223005 [3]河海大学马克思主义学院,江苏南京210098

出　　处：《河海大学学报（自然科学版）》2019年第1期32-40,共9页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金青年科学基金(51609060);江苏省自然科学基金青年科学基金(BK20150810);中央高校基本科研业务费专项(2017B14614)

摘　　要：采用单因素扰动分析法,分别对土壤水力参数残余含水量θr、饱和含水量θs、饱和导水率Ks、经验参数α和n进行扰动,选用HYDRUS-1D模型模拟南京市区2年一遇降雨条件下土壤水分入渗过程,分析变水头入渗条件下各土壤水力参数的敏感性,定量描述土壤水力参数变化对HYDRUS-1D输出变量土水势和累积入渗量的影响,简化后续模型率定工作,提高模型模拟精度。结果表明:在变水头入渗条件下,5个参数对土水势与累积入渗量敏感性排序均为n>Ks>θs>α>θr,其中α和n对于地表0～10 cm附近的土水势影响较大,Ks与θr,以及θs与α对土水势影响规律类似;±25%扰动情况下,θs、Ks与n三者对累积入渗量的影响均大于10%。因此,在进行变水头入渗条件下模拟计算中应保证Ks、θs、α和n参数的准确性。The single-factor perturbation analysis method was used for the sensibility analysis of soil hydraulic parameters,including the residual water content θr,the saturated water content θs,the saturated hydraulic conductivity Ks,the empirical parameters α and n.With the help of HYDRUS-1D model,the process of water infiltration in the soil was simulated for the two-year-once storm in Nanjing and the sensitivity of soil hydraulic parameter was evaluated for the varying-head infiltration,which can quantitatively describe the effects of soil hydraulic parameters on two output variables of HYDRUS-1D(soil water potential and cumulative infiltration),simplify the model calibration and improve the accuracy of model simulation.The results show that under the condition of varying-head infiltration,the parameter’s influence degree on both soil water potential and cumulative infiltration are in this order:n>Ks>θs>α>θr.Empirical parameters α and n have a great influence on the soil water potential with a depth of 0~10 cm beneath the surface,and the influence are similar when changing parameters Ks,θr or θs and α on the soil water potential.In the case of ±25% disturbance,the influence degree of θs,Ks and n on the cumulative infiltration are more than 10%.Therefore,the accuracy of Ks,θs,α and n should be ensured during the simulation of varying-head infiltration.

关 键 词：敏感性分析 非饱和土壤水运动 土水势 HYDRUS 变水头入渗 土壤水力参数 单因素扰动 数值模拟 

分 类 号：S152.7[农业科学—土壤学] TV12[农业科学—农业基础科学]