River modelling and flood mitigation in a Belgian catchment

Abstract

This paper describes the steps followed to propose solutions to recurring flooding problems in a Belgian catchment. Firstly, the hydraulic capacity (maximum discharge before bank overflow) of the cross sections was computed all along the river by an iterative 1D steady-state approach. In order to carry out these simulations, cross sections from site surveys of the river were integrated into the model, as well as hydraulic structures such as culverts, footbridges, and pipes. Secondly, the flooding problem was analysed with a time-dependant approach consisting of simulating floods following extreme rainfall events. The hydrological aspect was studied in a spatially distributed way using a multi-layer hydrological model. The available data on the basin such as the digital elevation model (DEM), the landuse, and the pedology were exploited to identify the basic modelling parameters. The hydrological contribution was routed by a 1D network resulting from the merging of the DEM-based and the cross section-based river networks. According to the results of the aforementioned steps, various local and catchment-wide solutions against flooding were proposed and analyzed. The comparison of simulated situations before and after these improvements allowed checking the effectiveness of the proposed solutions. 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 AbstractThis paper describes the steps followed to propose solutions to recurring flooding problems in a Belgian catchment. Firstly, the hydraulic capacity (maximum discharge before bank overflow) of the cross sections was computed all along the river by an iterative 1D steady-state approach. In order to carry out these simulations, cross sections from site surveys of the river were integrated into the model, as well as hydraulic structures such as culverts, footbridges, and pipes. Secondly, the flooding problem was analysed with a time-dependant approach consisting of simulating floods following extreme rainfall events. The hydrological aspect was studied in a spatially distributed way using a multi-layer hydrological model. The available data on the basin such as the digital elevation model (DEM), the landuse, and the pedology were exploited to identify the basic modelling parameters. The hydrological contribution was routed by a 1D network resulting from the merging of the DEM-based and the cross section-based river networks. According to the results of the aforementioned steps, various local and catchment-wide solutions against flooding were proposed and analyzed. The comparison of simulated situations before and after these improvements allowed checking the effectiveness of the proposed solutions.

Modelling of man-made flood routing in the lower Yellow River, China

“…Many numerical models have been developed to simulate flood routing in natural rivers, the majority of which solve the full St Venant equations (Castellarin et al, 2009;He et al, 2007;Khuat Duy et al, 2010;Lim and Cheok, 2009;Wang et al, 2004Wang et al, , 2010Wu et al, 2004). Simplified models have also been developed, such as approximations of the kinematic wave, non-inertia wave, quasi-steady dynamic wave and gravity wave, based on simplifications to the full momentum equation (Bates and De Roo, 2000;Chung et al, 1993).…”

Semi-Explicit Modelling of Watersheds with Urban Drainage Systems

“…The rainfall-runoff model used here is processoriented and spatially distributed (Khuat Duy et al, 2010). Using a multi-layer approach based on layer-averaged equations (Figure 1), it computes the main hydrological processes, including overland flow, interflow, infiltration and deep percolation.…”

Caractérisation micro-echelle du risque d’inondation : modélisation hydraulique détaillée et quantification des impacts socio-économiques

“…Depuis divers modèles simplifiés, jusqu'aux modèles hydrauliques unidimensionnels [2] et bidimensionnels, le choix d'une approche de modélisation doit être cohérente avec l'échelle de l'analyse de risque sous jacente [3]. Dans le cadre d'une approche micro-échelle, la représentation de la dynamique de l'écoulement revêt une importance capitale dans l'optique d'une quantification du risque pour laquelle chaque élément soumis à l'aléa est analysé individuellement.…”