Development of a distributed hydrological model based on urban databanks – production processes of URBS

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.

The effect of surface texture on evaporation, infiltration and storage properties of paved surfaces

“…These methods will often overestimate runoff and underestimate the recharge to groundwater (Ragab et al 2003) and do not reflect the complex pattern of urban water balance in the long term. (Rodriguez et al 2005), for example, have shown that there is a considerable variation in the runoff coefficient with different rainfall conditions while (Davies & Hollis 1981) showed that when the water balance is considered over a long period, evaporation, infiltration and depression storage may be more significant than runoff. Measurements of the water balance of two roads in France showed that infiltration and evaporation represented up to 30% of rainfall (Ramier et al 2006).…”

Which spatial discretization for distributed hydrological models? Proposition of a methodology and illustration for medium to large-scale catchments

“…agricultural fields), a simple combination of the available data can be used for homogeneous zones definition (e.g. Moussa et al, 2002;Rodriguez et al, 2005;Branger, 2007 -see also Sect. 5.3.).…”

Large-Scale GIS-Based Urban Flood Modelling: A Case Study on the City of Ouagadougou

“…Others have used models that were conceived to give a thorough representation of storm water and wastewater dynamics [Petrucci and Bonhomme, 2014], [Zarriello, 1998] and some have resorted to more « process based » models [Rodriguez et al, 2005] (see a review in [Elliot and Trowsdale, 2007] and [Zoppou, 2001]). However, using these models at the scale of large urban conglomerations is often cumbersome.…”