土壤水力特性异质性对土壤排水影响的瞬态随机分析

发布时间：2018-11-05 07:05

【摘要】：土壤剖面水分入渗及再分布对生态和水文建模十分重要,而土壤异质性导致垂向的导水率值差异非常大。因此,该文假设在单位梯度下,用微扰法和运动波模型并结合随机分析研究一维瞬态土壤剖面排水的问题。采用Brooks-Corey模型,设饱和导水率和模型参数为随机变量。结果表明:1)饱和导水率方差增大对排水过程具有减缓的作用,有效饱和导水率较小;2)土壤导水率异质性越大,土壤蓄水能力越强;3)比较模型参数的波动与饱和导水率方差和模型参数的协方差,饱和导水率方差对排水影响更大;4)田间排水试验的结论与模型预测相一致。研究可为以长期自我维持的生态系统和高田间持水量为目标的土壤复垦提供依据。
[Abstract]:Water infiltration and redistribution in soil profile are very important for ecological and hydrological modeling, and soil heterogeneity leads to great differences in vertical water conductivity. Therefore, this paper assumes that the problem of one-dimensional transient soil profile drainage is studied by using perturbation method and motion wave model under unit gradient and combining with random analysis. The Brooks-Corey model is used and the saturated water conductivity and the model parameters are assumed to be random variables. The results show that: 1) the increase of variance of saturated water conductivity has a slowing effect on the drainage process, and the effective saturated water conductivity is smaller, 2) the greater the heterogeneity of soil water conductivity is, the stronger the water storage capacity of soil is. 3) comparing the variances of model parameters with the variance of saturated water conductivity and the covariance of model parameters, the variance of saturated water conductivity has greater influence on drainage. 4) the results of field drainage experiments are consistent with the model prediction. The study can provide the basis for soil reclamation which aims at long-term self-sustaining ecosystem and high field water holding capacity.
【作者单位】：中国农业大学土壤与水科学系;西北农林科技大学水利与建筑工程学院;
【基金】：国家重点研发计划项目资助(2016YFD0800102) 国家自然科学基金资助项目(41371231)
【分类号】：S152.7

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