Are basin characteristics relevant for the estimation of lumped or semi-distributed rainfall-runoff model parameters?

Estimation of model parameters has been a major problem since the last two decades and if we want to address this problem in the context of ungauged basins it becomes much more challenging.We might think that technological progress in collecting spatialized data (Geographic Information Systems (GIS), Digital Elevation Models (DEM), radars~) offers the possibility to take into account the spatial variability of rainfall and watersheds physical characteristics, in rainfall-runoff models without carrying out any measurement in the field. To use this information, the lumped approach can be easily replaced by the semi-distributed approach. Nevertheless, the integration of expensive additional data into models is useless if it does not improve significantly their results. In this paper, we deal with the impacts of using physical heterogeneities of basins on the performances of lumped and semi-distributed approaches.