| 刘琨,黄冠华.采用基因表达式编程的沟灌入渗模型参数估计方法[J].水利学报,2017,48(11):1293-1302 |
| 采用基因表达式编程的沟灌入渗模型参数估计方法 |
| Parameter estimation for furrow infiltration model with Gene Expression Programming |
| 投稿时间：2017-06-28 |
| DOI：10.13243/j.cnki.slxb.20170633 |
| 中文关键词: 沟灌 入渗 参数估计 基因表达式编程 |
| 英文关键词: furrow irrigation infiltration parameter estimation gene expression programming |
| 基金项目:国家自然科学基金项目（51639009） |
|
| 摘要点击次数: 1840 |
| 全文下载次数: 1680 |
| 中文摘要: |
| 入渗参数的准确估计是沟灌系统设计优化的关键问题。本文基于基因表达式编程（GEP）算法，通过数值试验获得了沟灌入渗模型参数γ估计GEP算法所需的有效数据集合，进行了参数γ的敏感性分析，确定了模型参数γ估计GEP算法的输入因子及其最优组合，建立了γ与最优组合因子的定量关系，进而提出了γ的估计方法。研究结果表明，γ对积水深度、初始有效含水率和沟深度最敏感；土壤水力特性参数对γ影响较大，模型参数γ估计GEP算法的最优输入因子组合为积水深度、沟深、初始有效含水率、饱和导水率和进气值参数；变积水深度条件下γ的估计值与定积水深度的γ值相近；在变积水深度条件下，与利用HYDRUS-2D模型计算得到的"精确"入渗量相比，应用基于γ估计值的沟灌入渗模型计算的累积入渗量误差小于5%，满足计算精度要求。入渗过程中边界效应对总入渗量的贡献逐渐增大，与细质土壤相比，粗质土壤中边界效应对总入渗量的贡献更大，本研究条件下黏壤土中边界效应最终贡献约为25%，砂土中约为37%。研究表明GEP算法可作为沟灌入渗模型参数γ估计的一种有效方法。 |
| 英文摘要: |
| Accurate estimation of infiltration parameters is critically important for the optimal design of furrow irrigation system. In the present study, a method for estimating the edge effect parameter γ of furrow infiltration model was proposed by using of the gene expression programming (GEP) algorithm. A numerical experiment was conducted to produce the dataset for validating the GEP algorithm. The input factors of GEP algorithm were determined on the basis of the sensitivity analysis of γ,and then the quantitative relationship between γ and the optimal combination of input factors was established. The results show that γ is very sensitive to ponding water depth,initial effective water content and furrow depth. Soil hydraulic properties had a great influence on γ. The optimal combination of the input factors are the ponding water depth, furrow depth, initial effective water content, saturated hydraulic conductivity and inverse of the air-entry value. The estimated γ under the condition of variable ponding depth is approximately the same as those of constant ponding depth condition. For variable water depth, the difference between the cumulative infiltration obtained by using the furrow infiltration model with the GEP estimated γ and the "exact" cumulative infiltration calculated by HYDRUS-2D is less than 5%. The contribution of edge effect to total infiltration increases gradually during the infiltration process. Compared with the fine soil, coarse soil shows a larger edge effect on the total infiltration. The edge effect in clay loam is about 25%,and about 37% in sand un-der the conditions of this study. It can be concluded that the GEP algorithm is an effective method to estimate the parameter γ for the furrow infiltration model. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |