一维水流及溶质运移对VG模型参数的敏感性分析

发布时间：2018-03-16 20:28

本文选题：Hydrus-d　切入点：垂直一维模型　出处：《节水灌溉》2017年11期 　论文类型：期刊论文

【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:θrαnK_sθ_s,而溶质运移对5个参数的敏感度大小关系为:θ_rαK_sθ_sn;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。
[Abstract]:In order to study the effect of disturbance of five parameters in VG model on pressure head and solute migration, a one-dimensional unsaturated numerical model was constructed by Hydrus-1d, and a benchmark model was constructed by using NaCl as simulation solute and empirical parameters of loam soil. On the basis of the baseline scenario, the parameters of the VG model are disturbed up and down, and the model is replaced with the model to get the variation law of the pressure head and solute concentration with the depth of each scenario. On the basis of this, sensitivity analysis of each parameter is carried out. The results show that the influence of five parameters on pressure head and solute migration is different. The sensitivity of the pressure head to the five parameters is as follows: 胃 r 伪 nK_s 胃 s, while the sensitivity of the solute migration to the five parameters is as follows: 胃 r 伪 Ks 胃 S; 胃 rr 伪 Ks 胃 S; 胃 RavennKs; and the negative disturbance has a great effect on the pressure water head. The influence of positive disturbance on solute migration is great, 胃 s, 伪 is negative correlation, its positive disturbance has great influence on pressure water head, and negative disturbance has great effect on solute migration, and the sensitivity index of 胃 sn Ksn to pressure water head increases with the passing of simulation time. However, 伪 and 胃 _ r have the tendency of rising first and then decreasing. The sensitivity of 胃 _ s / Ks, 伪, 胃 _ r to solute migration shows a tendency of first increasing and then decreasing.
【作者单位】：华北水利水电大学资源与环境学院;
【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)
【分类号】：S152.7

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