Final report of Wageningen University contribution to FLOODsite Task 1

The hydrological response of catchments is influenced by the landscape characteristics. Both channel networks and hillslopes play a major role in the propagation of water within catchments, and therefore influence the generation of floods. In mountainous regions, the importance of subsurface flows has been recognized for a long time (e.g. Dunne and Black 1970, Freeze 1972a, Beven and Kirkby 1979). Moreover, the issue of hydrological modeling or forecasting in a context of poorly or ungauged basins adds a level of complexity by removing the possibility to calibrate hydrological models. In this report, we focus on the subsurface component of discharge at the hillslope scale (up to one km2), and in particular on the development of a new approach providing the ability to capture the essential behaviour of the natural system using a parsimonious and computational efficient modeling.