The roughness length for heat of sparse vegetation

A dual-source model that solves the energy balance over vegetation and soil separately can be inverted to obtain the roughness length for heat (z0h) of a single-source model. Model parameters for the dual-source model were taken from previous analysisof data from a sparse canopy in semi-arid terrain. In these circumstances, the value of z0h is shown to be dependent on the humidity deficit, the available energy, the vegetation fraction, and the surface resistance of the soil and the vegetation.