滴灌条件下水土温度对覆砂土壤水热运移影响的数值模拟  

Numerical Simulation of the Influence of Water and Soil Temperature on Water and Heat Transfer of Sand Mulching Soil Under Drip Irrigation

作　　者：虎军宏 赵文举[1] 刘贵元 胡家珍 HU Junhong;ZHAO Wenju;LIU Guiyuan;HU Jiazhen(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050

出　　处：《水土保持学报》2020年第5期349-354,360,共7页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(51869010);兰州理工大学红柳一流学科项目。

摘　　要：为探究滴灌条件下水温与土温对覆砂土壤水热运移规律的影响,基于HYDRUS-2D构建了不同水土温度土壤水热运移数值模型,模拟分析了不同水土温度对覆砂土壤水分、温度动态变化的影响。结果表明:灌溉水温对土壤水热分布影响显著,随着温度升高,土壤湿润体内含水率减小,表现为35℃水温<20℃水温<5℃水温,灌溉水温对土壤剖面温度分布也有较大影响,表层0-15 cm范围内温度变化了5~10℃。相同水温条件下,随着土壤温度升高,土壤饱和导水率增大,湿润土体内体积含水率减小,表现为30℃土壤温度<15℃土壤温度<5℃土壤温度。滴灌水平和垂直湿润锋运移距离随温度升高而增大,湿润锋运移距离与时间符合幂函数F=at b,决定系数R 2介于0.9774~0.9996,并建立了水平和垂直湿润锋运移距离与入渗时间和温度的关系模型。以期为西北干旱地区砂石覆盖生态农业的合理补灌提供理论指导。In order to explore the influence of water temperature and soil temperature on the water and heat transfer of sand mulched soil under the condition of drip irrigation,a numerical model of water and heat transfer of soil with different water and soil temperature was built based on HYDRUS-2D,and the influence of different water and soil temperature on the dynamic change of water and temperature of sand mulched soil was simulated and analyzed.The results showed that the irrigation water temperature has a significant effect on the distribution of soil water and heat.With the increase of temperature,the moisture content in the soil decreased,which shows that the water temperature of 35℃<20℃<5℃.The irrigation water temperature also had a great influence on the distribution of soil profile temperature,and the temperature changed 5~10℃in the range of 0-15 cm in the surface layer.Under the same water temperature,with the increase of soil temperature,the saturated hydraulic conductivity of the soil increased,and the volume moisture content of the wet soil decreased,which showd that the soil temperature of 30℃<15℃<5℃.The migration distance of horizontal and vertical wetting front of drip irrigation increased with the increase of temperature.The migration distance and time of wetting front accorded with the power function F=at b,and the determination coefficient R 2 was between 0.9774 and 0.9996.We established the relationship model between the migration distance of horizontal and vertical wetting front and infiltration time and temperature,in order to provide theoretical guidance for the reasonable supplement irrigation of the sand and gravel mulched ecological agriculture in the arid area of Northwest China.

关 键 词：覆砂 灌溉水温 土壤温度 湿润锋 数值模拟 

分 类 号：S152.7[农业科学—土壤学]