GIS-based ways for considering spatial heterogeneity of catchment characteristics

A GIS offers many options to present and to handle spatial heterogeneity of catchment characteristics. Some of these opportunities are presented here. The well-known equally-square grid is compared with a more process-oriente d sub-division of a catchment into hydrological similar units. It is shown how the entropy of information could be used as a measure to choose an appr opriated spatial resolution. A new way for a spatial sub-division of water balance models is proposed ill which the advantages of a grid are combined with a more process-oriented differentiation between spatial units with sim ilar hydrological characteristics which will be defined by clustering. (C) 2000 Elsevier Science Ltd. All rights reserved.