一维水流及溶质运移对VG模型参数的敏感性分析  

Sensitivity Analysis of VG Model Parameters to One Dimensional Water Flows and Solute Transport

作　　者：高志鹏[1] 屈吉鸿[1] 陈南祥[1] 李五金[1] 

机构地区：[1]华北水利水电大学资源与环境学院,郑州450045

出　　处：《节水灌溉》2017年第11期65-71,76,共8页Water Saving Irrigation

基　　金：水利部公益性行业科研专项经费项目(201501008);河南省高校科技创新人才支持计划(13HASTIT035)

摘　　要：为了研究VG模型中5个参数的扰动对压力水头和溶质运移的影响,采用Hydrus-1d构建一维非饱和数值模型,以NaCl为模拟溶质,以壤土的经验参数构建基准模型,并在基准情景的基础上对VG模型各参数上下扰动5%、10%,代入模型重新模拟,得到各情景下压力水头和溶质浓度随深度的变化规律,并在此基础上对各参数进行了敏感性分析。结果表明:5个参数对压力水头和溶质运移的影响规律不尽相同,压力水头对5个参数的敏感度大小关系为:θr<α<n<K_s<θ_s,而溶质运移对5个参数的敏感度大小关系为:θ_r<α<K_s<θ_s<n;θ_r、n、K_s的影响规律均为正相关,其负扰动对压力水头的影响大,而正扰动对溶质运移的影响大;θ_s、α的影响为负相关,其正扰动对压力水头的影响大,而负扰动对溶质运移的影响大;随着模拟时间的推移,θ_s、K_s、n对压力水头的敏感度指数呈上升趋势,而α和θ_r则呈先上升后下降的趋势;n、θ_s、K_s、α、θ_r对溶质运移的敏感度均呈现先增大后减小的趋势。In order to study the influence of VG model parameters on the pressure head and solute transport, using NaCI as the simulation solute and the empirical parameters of loam as the reference parameters, a one-dimensional unsaturated model is constructed as the standard model with the help of Hydrus-ld software. And then the reference parameters are disturbed by 5% and 10% up and down and taken into the model, then the variation of pressure head and solute concentration with depth can be got. Finally the sensitivity analysis is conducted for each parameter. The results show that the influence of 5 parameters on pressure head and solute transport are not the same. The order of the sensitivity of the pressure head to the 5 parameters is θr〈α〈n〈Ks〈θs, while the order of the sensitivity of the solute transport to the 5 parameters is θr〈α〈Ks〈θs〈n. Pressure head and solute transport are both positive with θr, n, Ks, the negative disturbance has a great influence on pressure head, while the positive disturbance has a great influence on solute transport. Pressure head and solute concentration are both negative with θs, a, the positive disturbance has a great influence on the pressure head, while the negative disturbance has a great influence on solute transport. The sensitivity index of pressure head to θs, Ks, n has an upward trend, while the trend to α and θr is increasing first and then decreasing. The sensitivity index of solute transport to θs, Ks, a,θr, n all increases firstly and then decreases.

关 键 词：HYDRUS-1D 垂直一维模型 VAN GENUCHTEN模型 参数敏感性分析 

分 类 号：S152.7[农业科学—土壤学]