摘要
为了探究初始含水率对管渠灌溉过程中湿润锋运移和水分分布的影响,通过室内土槽模拟试验与理论分析,研究了4种不同土壤初始含水率(2.58%、4.76%、6.36%、8.94%)对水分入渗特性的影响。结果表明:不同土壤初始含水率下的湿润体运移轨迹均呈现出垄内侧为直线型,垄外侧为曲线型;垂直和水平湿润锋运移距离随入渗时间的延长而增大;相同入渗历时,垂直和水平湿润锋的运移距离随土壤含水率增大而增大;分别建立了在管渠灌溉条件下垂直和水平湿润锋运移距离、入渗时间和土壤初始含水率之间的经验公式,其相关系数R2均大于0.9,满足精度要求;同一入渗时间下,垂直和水平湿润锋的运移速率随土壤初始含水率增大而增大,并随着入渗时间的增加,湿润锋运移速率迅速减小并趋于稳定;土壤初始含水率与湿润体内水分分布密切相关,含水率等值线随入渗深度的增加呈由疏到密分布,土壤初始含水率越大,湿润体内高含水率体积越大。
In order to identify the effects of soil initial content on the movement and distribution of wetting front in the process of canal irrigation,this paper explored the water infiltration properties of pipe canal irrigation under 4 different kinds of soil initial content(2.58%,4.76%,6.36%,8.94%)through indoor simulation and theoretical analysis.The results showed that the movement track of wet body under different soil initial moisture contents were linear in the ridge and curve outside the ridge.The distance of vertical and horizontal wetting front migration increased with the extension of infiltration time.In the same infiltration time,the migration distance of vertical and horizontal wetting front increased with the increase of initial soil moisture content.The empirical formulas of the wetting front migration distance,infiltration time and initial moisture content of soil were established respectively.The correlation coefficients were all greater than 0.9,which met the accuracy requirements.The speed of wetting front migration increased with the increase of soil moisture content and decreased with increasing infiltration time.At the same time,the speed of vertical and horizontal wetting front increased with the increase of initial soil water content,and decreased rapidly and tended to be stable.The initial soil water content was closely related to the water distribution in the wetting body.The contour of moisture content was distributed from sparse to dense with the increase of infiltration depth.The larger the initial moisture content of soil,the larger the volume of high moisture content in the wetted soil volume.
作者
李宗毅
张安琪
荣旭
王春堂
LI Zong-yi;ZHANG An-qi;RONG Xu;WANG Chun-tang(College of Water Conservancy and Civil Engineering/Shandong Agricultural University,Tai’an 271018,China)
出处
《山东农业大学学报（自然科学版）》
北大核心
2021年第2期270-276,共7页
Journal of Shandong Agricultural University：Natural Science Edition
基金
山东省重点研发计划项目(2018GNC110015)
山东省自然科学基金项目(ZR2017MEE001)。
关键词
土壤湿度
灌溉
渗水性
Soil humidity
irrigation
water permeability
