Network representation in hydrological modelling on urban catchments in data-scarce contexts: A case study on the Oued Fez catchment (Morocco)

Study region: Oued Fez, Morocco. Study focus: Urban catchments are heterogeneous in terms of land use and have both natural and artificial drainage networks. Modelling them is not a straightforward task especially in data-scarce settings. This study investigates network representation in hydrological modelling using field data collected between 2008 and 2018 on the Oued Fez catchment. The road network is used as a proxy for the stormwater network. Two production functions, SCS (1972) and a linear reservoir, are coupled to the lag and route transfer function. Three types of land use classes are used. Tests are carried out at hourly and 5-minute time steps using both the natural and modified drainage networks. New hydrological insights for the region: Fifty-three rainfall–runoff events are monitored on the urban part of the catchment over the 2008–2018 period. The highest rainfall values are recorded in 2008/2009, while the highest peak flow values are recorded in 2017/2018. This is due to stream channelisation and increased stormwater network coverage. Using the road network with minimal land use classes improves the model performance at both the hourly and 5-minute time steps.