The influence of urban canopy configuration on urban albedo

We propose a calculation method for shortwave radiation flux and longwave r adiation flux within the urban canopy and investigate the influence of urba n canopy configuration on net radiation flux. In the assumed urban configur ation, buildings of equal size are arranged in a regular lattice within the urban canopy. The net shortwave radiation flux and longwave radiation flux within the urban canopy were calculated by the photon tracking method base d on the Monte Carlo method. The albedo value obtained by this method shows close agreement with experimental data, and the average sky view factor sh ows almost perfect agreement with the theoretical value. Moreover, we calcu lated the urban albedo for the urban canopy configuration including roads a nd building height distribution. We found that the sky view factor of the g round surface is high when building coverage is low, building height is low , open space by roads exists, and building height is non-uniform. Moreover, we found that the albedo value is high when building height is small, open space by roads is wide, and building height is uniform. The albedo value w as found to vary in a complicated manner with change in building coverage.