湿分分层土壤中热湿迁移与水分蒸发的实验研究  

EXPERIMENTAL STUDIES ON HEAT AND MOISTURE TRANSFER AND SOIL WATER EVAPORATION UNDER NATURAL CONDITION

作　　者：刘炳成[1] 刘伟[1] 杨金国[1] 

机构地区：[1]华中科技大学能源与动力工程学院,湖北武汉430074

出　　处：《工程热物理学报》2004年第6期1004-1006,共3页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展规划项目资助(No.G2000026303);国家自然科学基金项目资助(No.50376015);教育部博士点基金项目资助(No.2000048731)

摘　　要：在自然环境下,对土壤中温度和湿分分布以及水分蒸发的动态特性进行了实验研究,分析了干饱和层对土壤热湿迁移及水分蒸发的影响。结果表明: (1)在周期性变化的大气环境条件下,土壤温度、湿分含量和水分蒸发强度在一天内变化;随着土壤温度的降低,土壤水分含量在晚上会出现略有增加的情况。(2)形成干饱和层后,水分蒸发锋面由土壤表面下移至非饱和层与干饱和层界面处,水分蒸发强度明显减弱,干饱和层的厚度增长缓慢。(3)随着干饱和层不断向深处发展,土壤温度的日变化幅度增大,且随着土壤深度的增加,土壤温度变化呈现出明显的滞后性。Under natural environment the variations of soil temperature, water content and evaporation intensity were observed in a cylindrical soil bed and the influence of dry region on heat and moisture transfer in soil bed and water evaporation was analyzed. The results indicated that, (1) Soil temperature, water content and evaporation rate exhibit periodical variation with the daily changes of solar radiation, atmospheric temperature and relativity humidity. Along with temperature decreasing at night, soil water content would increases slightly. (2) Starting from the occurrence of dry soil layer (DSL), water evaporation front moves from soil top surface to the interface between unsaturated layer and dry layer. The decrease of water evaporation intensity is remarkably and the thickness of DSL develops slowly. (3) With the development of dry soil layer, the increase of surface soil temperature fluctuating range is obvious. In addition soil temperature presents a distinct hysteresis along with the increase of soil depth.

关 键 词：土壤 干饱和层 非饱和层 土壤温度 水分蒸发 

分 类 号：S152.8[农业科学—土壤学]