| 引用本文: | 张 健,魏占民,张金丁,等.渠道土壤含水率的时空变化及渗漏模拟研究[J].灌溉排水学报,0,():-. |
| ZHANG Jian,WEI Zhanmin,ZHANG Jinding,et al.渠道土壤含水率的时空变化及渗漏模拟研究[J].灌溉排水学报,0,():-. |
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| 渠道土壤含水率的时空变化及渗漏模拟研究 |
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张 健1, 魏占民1, 张金丁1, 杨旭东1, 苏日娜2
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1.内蒙古农业大学水利与土木建筑工程学院;2.内蒙古自治区水利新闻宣传中心
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| 摘要: |
| 为探明渠道土壤含水率的时空变化及不同水深条件下渠道渗漏规律,采用恒水位静水试验的方法进行渠道渗漏试验,试验设置8个入渗水头,分析渠道土壤含水率的时空变化规律,探究不同水深、质地条件下渠道的累积入渗量及入渗速率的变化规律。基于田间层状土壤条件下开展的渠道渗漏试验研究,建立了二维空间上饱和-非饱和有压水头的土壤水分入渗模型,采用HYDRUS-2D软件对试验渠道及均质粉土、粉壤土的渠道进行模拟。试验结果表明：(1)当土壤剖面存在分层界面时,临界面对水分入渗具有缓阻作用,分层界面下部位置达到饱和含水率的时间相应增长,且到达一定时间后,缓阻现象消失,水分通过分层界面后,水分入渗呈线性均匀的变化。(2) 利用HYDRUS-2D软件对试验渠道的水分入渗速率及累积入渗量进行模拟,经实测试验数据验证,试验模拟效果较好,用于渠道渗漏评价入渗速率和累积入渗量是可行的。分析得出随着渠道水深的增大,入渗速率越大,累积入渗量的变化越大。因为势能的变化为水分在土壤内运动的主要驱动力渠道水深与土壤水势梯度正相关,因而与渗漏通量正相关。 (3) 渠道土质越黏重,土粒间孔隙就越小,水流渗漏的阻力越大,水力传导度越小,土壤持水能力越大,渠道的渗漏损失越小。本研究成果可为灌区节水工程改造实施、灌溉水有效利用系数的控制指标及区域水资源评价等提供方法和手段。 |
| 关键词: HYDRUS-2D;层状土壤;渠道渗漏;土壤含水率;数值模拟 |
| DOI： |
| 分类号:S274 |
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| Spatio-temporal Variations of Soil Moisture Content in Channel and Seepage Simulation Study |
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ZHANG Jian1, WEI Zhanmin1, ZHANG Jinding1, YANG Xudong1, SU Rina2
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1.College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University;2.Center of Water Conservancy News Propaganda of Inner Mongolia Municipality
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| Abstract: |
| Proven channel spatial and temporal variations of soil moisture content and different water depths under the condition of channel seepage law, adopt the method of constant hydrostatic test water channel leakage test, a test set up 8 infiltration water head, space-time change law of soil moisture content, analysis of channel to explore the channels to the cumulative infiltration amount under the conditions of different water depth and the change rule of infiltration rate. Based on the experimental study of channel seepage in layered soil in the field, a two-dimensional saturated-unsaturated soil water infiltration model with pressurized head was established. Hydrus-2d software was used to simulate the channel and the channels of homogeneous silty soil and silty loam. The experimental results show that :(1) when the stratified interface exists in the soil profile, the critical interface has a moderating effect on water infiltration, and the time for the lower part of the stratified interface to reach the saturated moisture content increases correspondingly, and after reaching a certain time, the moderating phenomenon disappears, and water infiltration changes linearly and uniformly after passing through the stratified interface. (2) the water moves in the soil, and the change of potential energy is the main driving force. The change of channel water depth causes the change of pressure potential, and the water depth is positively correlated with the gradient of water potential in the soil of the channel bed, so it is positively correlated with the leakage flux. (3) the more viscous and heavy the channel soil, the smaller the pores between the soil particles, the greater the resistance to water leakage, the smaller the hydraulic conductivity, the greater the soil water holding capacity, and the smaller the leakage loss of the channel. The results of this study can provide methods and means for the implementation of water-saving engineering transformation in irrigated areas, the control index of effective utilization coefficient of irrigation water and regional water resources evaluation. |
| Key words: Hydrus-2D; Layered Soil; Channel Leakage; Soil Moisture Content; The Numerical Simulation |
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