No abstract

The objective of this study is to present a distributed hydrological model especially dedicated to urban catchments, and able to represent hydrological processes usually neglected in urban modelling, such as evapotranspiration, infiltration in roads, or direct infiltration of soil water in sewers. This model, called URBS (as Urban Runoff Branching System) is distributed considering the spatial variability of land use which is well known thanks to urban databanks managed by GIS. The production function is detailed at each cadastral parcel scale, and the runoff produced is routed by a simple transfer function. The estimation of the input parameters of the model is mostly based on physical considerations, and the model has been first applied on a small sub-urban catchment (Rezé, 5 ha) in order to evaluate the performance of this production function. Both the water fluxes from the different land use types and the saturation level have been analysed and compared to those data, the results are encouraging.

No abstract

This study presents the implementation of innovative stormwater techniques into a distributed hydrological model. This model, is able to represent hydrological processes usually neglected in urban modelling, such as evapotranspiration, infiltration in roads, or direct infiltration of soil water in sewers. The introduction of innovative stormwater techniques such as flat roofs, permeable reservoir pavements or tree plantation can be easily performed in this very modular model. A small urban catchment in Nantes (France) is taken as case study to analyse the influence of these innovative techniques on the hydrological catchment behaviour. The influence of innovative stormwater techniques on the distribution of runoff sources in the catchment, and on total runoff, varies between scenarios. The biggest runoff reduction is delivered by widespread application of flat roofs.