Abstract
The conception of surface moisture availability is introduced and its values are estimated from the meteorological data in the surface boundary layer. By use of this conception, the daily evaporation from the non-saturated surface is very well parameterized with the air temperature at the roughness height and the water content of soil near the surface.
The relation between the surface moisture availability and the water content of soil agrees well with the results obtained by methods different from ours.
It is suggested that for parameterization effectual to the diurnal variation of evaporation it is necessary to investigate the transport mechanism of soil water content in the skin layer near the surface.
Under a certain assumption, it is tried to evaluate the soil water content in the skin layer. Its diurnal variation obtained seems to be reasonable.
