2004 Volume 48 Pages 157-162
This paper describes unsaturated soil characteristics in low moisture content and influences of soil moisture content in evaporation from soil surface. The vapor diffusivity in the soil was measured using the unsteady method proposed by Currie (1960). The water retention curve and the hydraulic conductivity were determined by laboratory experiments using a psychrometer. A numerical analysis for waterand vapor movement in the lysimeter is carried out. The calculated results indicate that the effects of the vapor movement on evaporation are negligible in the lysimeter. A method of estimate for evaporation using the meteorological condition and the soil moisture content is proposed, and its usefulness is confirmed by comparing the calculated and the observed results.
