A combined temperature and water content model for bare soil

The authors have developed a combined temperature and water content model for bare soil in one spatial dimension (depth) and time. The main purpose of the model is the study of the surface temperature variations due to a number of environmental parameters. In addition the authors also study the water content of the soil due to the great influence of evaporation. They characterize the soil by the thermodynamic and water tension properties. Experimental data have been used to support the model development. The core of the model is two coupled differential equations, one describing the temperature and the heat flow of the soil and one handling the water fraction and the soil water flow. The thermodynamic parameters of the heat flow depend on the water content. At the soil surface they model the heat exchange due to solar radiation, the thermal radiation exchange between the soil and the sky, the heat exchange due to air (and rain) convection and the exchange of sensible heat (mainly evaporation). They suppose no heat flow through the bottom surface