Author(s): Emmanuel Mignot; Clement Fagour; Gael Fontaine; Benjamin Froquet; Sebastien Proust; Nicolas Riviere; Pierre Archambeau; Pratik Chakraborty; Benjamin Dewals

Linked Author(s): Sébastien Proust, Benjamin J. Dewals

Keywords: Urban flood; Pollution; Transport; Modelling

Abstract: The present study aims to simulate numerically the spreading of a pollution caused by a flood in an urban area. Addison-Atkinson et al. (2022) and Genouel et al. (2024) showed that the flow in flooded streets carries a wide range of material: from urban furniture to dissolved matters. The present work focuses on the matter dissolved in the water, including chemical and bacteriological matters which generate huge sanitary issues. Such calculation is usually performed using the depth- and Reynolds-averaged 2D advection-diffusion equation (2D-ADE). In this equation, the horizontal turbulent and molecular concentration fluxes and the velocity-concentration dispersion terms are modelled altogether using a diffusivity tensor. Nonetheless, no consensus exists regarding this diffusivity tensor. A flood invading an urban district with semi-porous building blocks was reproduced at small laboratory scale with a release of scalar that mimics a pollutant transported by the flow that enters the blocks. The 2D-ADE was then used to assess the current numerical capacity of reproducing pollutions in urban floods.

DOI:

Year: 2025