A comparison of three dual drainage models: shallow water vs local inertial vs diffusive wave

This is the author accepted manuscript. The final version is available from IWA Publishing via the DOI in this record.In this study we compared three overland flow models, a full dynamic model (SWE), a local\udinertial equations model (GWM), and a diffusive wave model (PDWAVE). The three models are\udcoupled with the same full dynamic sewer network model (SIPSON). We adopted the volume\udexchange between sewer and overland flow models, and the hydraulic head and discharge\udrates at the linked manholes to evaluate differences between the models. For that purpose we\uddeveloped a novel methodology based on RGB scale. The test results of a real case study show\uda close agreement between coupled models in terms of the extents of flooding, depth and\udvolume exchanged, despite highly complex flows and geometries. The diffusive wave model\udgives slightly higher maximum flood depths and a slower propagation of the flood front when\udcompared to the other two models. The Local inertial model shows to slight extent higher\uddepths downstream as the wave front is slower than the one in the fully dynamic model.\udOverall, the simplified overland models can produce comparable results to fully dynamic\udmodels with less computational costThis research is partially funded by the FCT\ud(Portuguese Foundation for Science and Technology) through the Doctoral Grant\udSFRH/BD/81869/2011 financed through the POPH/FSE program (Programa Operacional\udPotencial Humano/Fundo Social Europeu). This study had the support of the Portuguese\udFoundation for Science and Technology (FCT) Project UID/MAR/04292/2013 and the UK’s\udNatural Environment Research Council (NERC) Project Susceptibility of catchments to INTense\udRAinfall and flooding (SINATRA, NE/K008765/1)