Experimental Study on Water and Heat Balance at Bare Soils in Lysimeters

Abstract

Water balance in lysimeters with bare surface was studied under the condition of artificially controlled room temperature and humidity and soil temperature. Evaporation was found to dominate the water balance there. The evapora-tion was investigated by the use of an “evaporation” pan and from a viewpoint of heat balance. The reasonable evaporation rates were evaluated by the heat balance method. The evaporation process in the lysimeters was categorized as the constant-rate stage for each experimental condition. The sensible heat flux was found to almost always enhance evaporation in this series of experiment.