Abstract
The transport process of heat and water between air and soil surface was studied by a laboratory experiment and a one-dimensional multi-layer soil model. An insulated column (φ200mm, depth650mm) packed with soil (sand16.0%, silt33.8%, clay50.2%) was set up in an indoor laboratory. Soil characteristics needed for numerical simulations, such as matric potential, hydraulic and thermal conductivity, were preliminarily measured. Radiation influx to the soil surface was kept at a constant 155(Wm)^<-2> and wind speed was set at 0.8(ms)^<-1>. Air temperature was 10-15℃ in the 7-days experiment. Temperature and volumetric water content in the soil column at 30,45,60,100,160,260,460,and 650-mm depth were monitored. The experiment and numerical simulation showed that temperature and water content at the surface ranged from 11.5 to 13.5℃ and from 0.296 to 0.308m^3m^<-3>, respectively, depending on air temperature and humidity. While those at 460-mm depth remained constant at 11.0-12.5℃ and 0.301-0.308m^3m^<-3>. The average evaporation flux from soil to air was estimated to be 1.5×(10)^<-5>(kgm)^<-2>s^<-1>.
