Application of GIS and remote sensing in flood modelling for complex terrain

An hourly distributed watershed model compatible with GIS and remote sensing for Water and Energy Transfer between Soil, Plants and Atmosphere (WetSpa) is presented in this paper. The model combines elevation, soil and land use data within a GIS framework, and predicts the flood hydrograph and spatial distribution of hydrological characteristics over a river basin. Algorithms derived as much as possible from physical processes, together with more conceptual or empirical algorithms, have been selected. The model was applied to the 407-km(2) Steinsel watershed in the Alzette River basin, Grand-Duchy of Luxembourg. Results of model simulation show that the model's level of representativeness is quite satisfactory. The model accounts for spatially distributed hydrological and geophysical characteristics of the watershed and is suitable for predicting the outflow hydrograph, evaluating storm runoff contributions from different land use classes, and assessing the impact of land use changes on flood behaviours in a complex terrain.