摘要
地表浅层土壤水热状态是影响发生在该区域物理、生物和化学过程的关键要素。针对地表浅层土壤含水率低、温度变化大的特点,应用Hydrus-1D软件构建热源作用下一维非饱和土壤水-汽-热耦合迁移理论模型,进行砂土不同初始含水率下有无水蒸气迁移的数值模拟研究。结果表明:与仅考虑液态水迁移相比,考虑水蒸气迁移后,砂土含水率迁移加剧,温度上升速度加快;砂土的初始含水率越小,水蒸气迁移对砂土的水分迁移和温度变化影响越大,随着含水率的不断增加,水蒸气迁移对砂土含水率和温度影响的效应逐渐降低直到消失。因此,在低含水率砂土的水热迁移模拟研究中,应考虑水蒸气迁移因素,以提高模拟精度,在含水率较高的砂土中,可忽略水汽的迁移影响,以简化计算。
The hydrothermal state of shallow soil is the key factor affecting physical,biological and chemical processes in the region.According to the characteristics of low moisture content and large temperature variation of shallow soil on the surface,a theoretical model of one-dimensional coupled water-vapor-heat migration in unsaturated soil under the action of heat source is constructed by using Hydrus-1D software.The numerical simulation of vapor migration in sand with different initial moisture content was carried out.The results show that compared with only considering liquid water migration,the whole moisture migration quantity of sand increases and the temperature rises faster after considering vapor migration;the smaller the initial moisture content of sand is,the greater the effect of vapor migration on the whole moisture migration and temperature change is;with the increase of water content,the effect of vapor migration on water content and temperature decreases gradually until disappearing.Therefore,in the study of hydrothermal migration of sand with low moisture content,the vapor migration factor should be considered to improve the simulation accuracy,and in the sand with high moisture content,this factor can be neglected to simplify the calculation.
作者
郭毅
晋华
桂金鹏
GUO Yi;JIN Hua;GUI Jin-peng(College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《节水灌溉》
北大核心
2019年第8期102-107,共6页
Water Saving Irrigation
基金
国家自然科学基金项目(41372247)
山西省回国留学人员科研资助项目(2017-045)
