Analysis of two sources of variability of basin outflow hydrographs computed with the 2D shallow water model Iber: Digital Terrain Model and unstructured mesh size

•Analysis of the combined effect of computational mesh and DTM resolutions.•Study conducted in 4 basins and a total of 7 precipitation events.•In each basin, 3 DTM resolutions and 3 mesh resolutions were considered.•Rainfall events were modelled with a fully distributed hydrodynamic 2D-SWE model.