Estimation of '"effective"" soil hydraulic properties by top soil moisture and evaporation modelling applied to an arable site in Central Spain.

A surface moisture model for large-scale semiarid land application has been extended with a moisture flow routine for capillary flow. The model has been applied to a field-scale data set of topsoil moisture and latent heat flux of an arable site in central Spain. A comparison of the soil hydraulic properties, determined by model simulations and measurements in the field, demonstrates the capability of the model to determine these properties out of a range of soil classes as defined according to the parameterization by Clapp and Hornberger [1978]. Estimation of area average or 'effective' soil physical parameters according to this approach requires time series of topsoil moisture and actual evapotranspiration on a patch or regional scale. Therefore this approach has potential for use with remotely sensed data.