A coupled, physically-based, spatially distributed hydrological model of surface and groundwater flow is being set up to assess, for various scenarios, the spatio-temporal patterns of response variables such as groundwater recharge, groundwater levels, and streamflow for a semi-arid catchment in northeastern Tunisia. The modeling scenarios will explore the impacts of surface and subsurface heterogeneities, boundary conditions, and expected climate change. This report describes the preliminary work that has been undertaken for this study, focusing in particular on interpretation and elaboration of the available data and on the set up of the model.