Abstract
In order to investigate air-earth interaction, a systematic measurement system near the surface was developed and installed in the observation field after careful examination of instruments and data processing.
Some aerodynamic approaches are provided for the determination of the vertical turbulent fluxes of heat and water vapor. Actual evaporation from the land surface is obtained from a weighable lysimeter of high sensitivity. The gradient method among the aerodynamic approaches provides a good estimate of evaporation.
The relationships between evaporation and soil water content are investigated in detail by means of the lysimeter and electrical capacitance meters placed in the soil container of the lysimeter. The data show that the soil water content in the skin layer changes appreciably in a day and that its variation corresponds closely to the unevenness of the evaporation.
