Development and Assessment of the Physically-Based 2D/1D Model “TRENOE” for Urban Stormwater Quantity and Quality Modelling

Yi Hong,Céline Bonhomme,Ghassan Chebbo

doi:10.3390/w8120606

Abstract

The widespread use of separate stormwater systems requires better understanding of the interactions between urban landscapes and drainage systems. This paper describes a novel attempt of developing urban 2D-surface and 1D-drainage model “TRENOE” for urban stormwater quantity and quality modelling. The physically-based TREX model and the conceptual CANOE model are integrated into the TRENOE platform, highlighting that the roofs of buildings are represented separately from the surface model, but simulated as virtual “sub-basins” in the CANOE model. The modelling approach is applied to a small urban catchment near Paris (Le Perreux sur Marne, 0.12 km2). Simulation scenarios are developed for assessing the influences of different “internal” (model structure, numerical issues) and “external” (parameters, input data) factors on model performance. The adequate numerical precision and the detailed information of land use data are identified as crucial elements of water quantity modelling. Contrarily, the high-resolution topographic data and the common variations of the water flow parameters are not equally significant at the scale of a small urban catchment. Concerning water quality modelling, particle size distribution is revealed to be an important factor, while the empirical USLE equations need to be completed by a raindrop detachment process.

Highlights

Separate sewer discharges are widely recognized for their deleterious impact on receiving water bodies
The results will be presented step by step in order to illustrate the influence of different factors on model outputs
Since the major benefit of using high-resolution LiDAR data is to ensure that water flows in appropriate directions, the present study indicates that the flow directions in the TRENOE model are appropriate directions, the present study indicates that the flow directions in the TRENOE model generally well represented even with coarser resolution topographic data

Summary

Introduction

Separate sewer discharges are widely recognized for their deleterious impact on receiving water bodies. Combined sewer overflows were traditionally considered to be the major cause of water quality degradation in urban waterways, the impacts of stormwater discharges has been recently attracting more attention with separate networks taking over combined ones [1,2,3]. The high levels of pollution frequently observed in stormwater outflows are shown to significantly contribute to the environmental pressure of urban areas on water streams, from which the importance of a proper evaluation of these discharges emerges [4,5]. The modelling of urban stormwater can be split into two components: the simulation of water quantity and the simulation of water quality. Despite the rapid development of hydrological modelling during last decades, the water quality component of urban stormwater modelling remains far less studied. Surface modules of the well-known SWMM [8] and MUSIC [9] models are respectively based on

Objectives

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Conclusion