Evaporation and Heat Convection Through a “Smartly Designed” Structured Topsoil

Experimental measurements of the volumetric moisture content and temperature in a composite soil were done during March-May in an open area subject to direct solar radiation in Muscat, Oman. The composite was made of a silt block and sand sheath adjacent to five faces of the block, with one face open to direct evaporation. For a two layered composite soil, an analytical solution is obtained for 1-D evaporation between two isobaric horizons. A composite of minimal water losses is found by varying the thickness of the upper coarse stratum. Convection in this composite was modeled for cyclostationary temperature variations at the soil surface.