土壤水力参数对点源入渗湿润体形状的影响
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金面上项目(51679190、51979220)、国家自然科学基金重点项目(41830754)和国家重点研发计划项目(2016YFC0501401-02)


Influence of Soil Hydraulic Parameters on Soil Wetting Pattern Shape of Point Source Infiltration
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    为探究点源积水入渗的运移机理,以达西定律和质量守恒原理为基础,利用HYDRUS软件对点源积水入渗过程进行数值模拟分析与验证,分析点源积水入渗条件下土壤水平湿润锋与垂直湿润锋的比值(湿润锋比)和土壤水力参数(进气吸力、形状系数以及饱和导水率)之间的关系,并基于土壤饱和扩散率建立水平湿润锋运移模型。结果表明:细质土壤(进气吸力大于11cm)的湿润体形状近似为以积水中心为椭圆心、以垂直湿润锋和水平湿润锋为长半轴和短半轴的椭圆体,而粗质土壤(进气吸力小于8.7cm)湿润体的椭圆心位于积水中心下方,从而导致短半轴大于水平湿润锋、长半轴小于垂直湿润锋;细质土壤的湿润锋比随时间变化较小,可近似为常数,土壤湿润锋比与形状系数和饱和导水率之间无显著的函数关系,但与进气吸力呈线性递增关系,决定系数R2为0.999;湿润锋运移过程可以采用入渗时间的幂函数进行拟合,且幂函数系数和指数可以分别用土壤饱和扩散率的一次多项式和二次多项式进行估计,经验证得到的模型在误差允许范围内具有较好的效果。本研究可为分析点源积水水盐运移等问题提供机理性依据,也为我国北方干旱半干旱地区合理规划设计滴灌系统、提高农业灌溉用水效率提供科学依据。

    Abstract:

    In order to research the migration mechanism of the surface ponding infiltration, the HYDRUS software was used to simulate and verify the process of surface ponding infiltration based on Darcy law and mass conservation principle. The relationship between the ratio of horizontal wetting front to vertical wetting front and soil hydraulic parameters (air-entry suction, shape coefficient and saturated water conductivity) was analyzed, and a horizontal wetting front migration model was established by using soil saturated diffusion rate. The results showed that the shape of wetting pattern of fine soil was approximately an ellipsoid with the center at ponding center, and the vertical and horizontal wetting fronts were the long and short semi-axes, respectively. However, the center of the coarse soil wetting pattern was located below the ponding center, thus the short semi-axis was larger than the horizontal wetting front, and the long semi-axis was smaller than the vertical wetting front. Wetting front ratios of fine soil was changed little with time and can be assumed as a constant. There was no significant functional relationship between wetting front ratio and shape coefficient or saturated water conductivity, but it was linearly increased with the increase of air-entry suction with R2=0.999. The power function of infiltration time can be used to describe the wetting front migration and the coefficient and index in power function can be estimated by the first and second polynomials of soil saturated diffusivity. It was verified that wetting front model had a good effect within the allowable error range. The research result can provide a more rational tool for the analyzing of surface ponding water migration. Meanwhile, it also provided a scientific theory for design of drip irrigation system in arid and semi-arid regions in northern China and improving the agricultural irrigation water use efficiency.

    参考文献
    相似文献
    引证文献
引用本文

苏李君,蔺树栋,王全九,王康.土壤水力参数对点源入渗湿润体形状的影响[J].农业机械学报,2020,51(1):264-274.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2019-10-15
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2020-01-10
  • 出版日期: