EVAPORATION AND SALT MOVEMENT IN SOILS IN PRESENCE OF WATER TABLE

Evaporation from homogeneous and stratified columns, in the presence of shallow water table, at steady state, was examined. Soils from Syria and Egypt were used. Their hydraulic conductivity-moisture tension curves were determined and fitted to smooth curves represented by W. R. Gardner's empirical formula. Solutions obtained by Gardner for the steady flow equations were modified for the boundary conditions of the top and bottom layers then reduced to a dimensionless form with two variables, the relative flux density, and the relative tension at the interface. The resulting equations were used to calculate the evaporation rates. Salt profiles near the surface, at different evaporation rates, were also studied.