Basic Considerations on Upscaling for the Evaporation Model

Abstract

A grid square of a meso-scale or macro-scale hydrological model usually includes various kinds of single land-use surfaces (elements). In order to estimate three fluxes from a grid square, fluxes from each element have to be averaged. For this purpose, Scale Issue has been researched by many researchers.
In this paper, numerical simulations were undertaken and considerations about upscaling from micro-scale to meso-scale was also undertaken, focusing on the aerodynamic resistance between the surface and the ‘blending height’. Defining the resistance of a whole grid square by parallel summation of the corresponding elemental resistances, the areal average fluxes were found to be similar.