GIS and Remote Sensing in Hydrology, Water Resources and Environment (Proceedings of ICGRHWE held at the Three Gorges Dam, China, September 2003). IAHS Publ. 289, 2004, 50-58

1 Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium

2 Research Unit in Environment and Biotechnologies, Centre de Recherche Public-Gabriel Lippmann,
162a Avenue de la Faïencerie, L-1511 Luxembourg

Abstract This paper describes the development of a comprehensive subcatchment parameterization method for medium and large-scale watershed modelling based upon the fully distributed WetSpa model. A simplified approach is used in order to take advantage of the existing spatial analysis function within ArcView GIS and its Spatial Analyst and hydrological modelling extensions. The model combines elevation, soil and land use data within a GIS framework, and predicts the flood hydrograph and water balance over a river basin. The method of diffusive wave approximation is applied in tracing water for both overland flow and channel flow, while the water and energy budget are maintained for each very small watershed derived from the high resolution DEM. The method was applied to the Alzette River basin, an 1176-km² medium-size watershed in the Grand-Duchy of Luxembourg. Good agreement between the predicted and measured hydrograph has been achieved according to the graphical comparison and statistical assessment.

Key words Alzette River basin; ArcView; diffusive wave; watershed modelling