THE PARAMETERIZATION OF REGIONAL EVAPORATION - SOME DIRECTIONS AND STRATEGIES

The success of currently available methods, or predicting runoff and other facets of watershed hydrology, depends critically on a knowledge of the water 'losses' through evaporation. Also, general circulation models in climate dynamics appear to be quite sensitive to the statement of land surface processes in general, and of evaporation in particular. Several approaches dealing with this problem have resulted from advances in the description of turbulent transport phenomena in the atmospheric boundary layer. Issues under investigation are the dissimilarity between sensible and latent heat transport, the simple slab concept for budget calculations and the development of bulk transfer equations. A number of large-scale experiments, some just completed, others about to start or in the planning stage will improve present understanding and parameterization techniques for surface fluxes of water vapor and related land surface processes.