Use of 3D classified topographic data with FullSWOF for high resolution simulation of a river flood event over a dense urban area

TL;DR

This paper explores the integration of high-resolution 3D classified topographic data with the FullSWOF hydrodynamic model to improve high-resolution urban flood simulations, addressing technical challenges and demonstrating potential benefits.

Contribution

It assesses the feasibility and advantages of using detailed 3D topographic data with FullSWOF for urban flood modeling, highlighting its numerical robustness and suitability.

Findings

FullSWOF effectively handles flow regime changes in urban flood simulations.

High-resolution 3D data enhances the accuracy of overland flow modeling.

FullSWOF's properties improve simulation stability and positivity preservation.

Abstract

High resolution (infra-metric) topographic data, including photogram-metric born 3D classified data, are becoming commonly available at large range of spatial extend, such as municipality or industrial site scale. This category of dataset is promising for high resolution (HR) Digital Surface Model (DSM) generation, allowing inclusion of fine above-ground structures which might influence overland flow hydrodynamic in urban environment. Nonetheless several categories of technical and numerical challenges arise from this type of data use with standard 2D Shallow Water Equations (SWE) based numerical codes. FullSWOF (Full Shallow Water equations for Overland Flow) is a code based on 2D SWE under conservative form. This code relies on a well-balanced finite volume method over a regular grid using numerical method based on hydrostatic reconstruction scheme. When compared to existing industrial codes used for urban flooding simulations, numerical approach implemented in FullSWOF allows to handle properly flow regime changes, preservation of water depth positivity at wet/dry cells transitions and steady state preservation. FullSWOF has already been tested on analytical solution library (SWASHES) and has been used to simulate runoff and dam-breaks. FullSWOFs above mentioned properties are of good interest for urban overland flow. Objectives of this study are (i) to assess the feasibility and added values of using HR 3D classified topographic data to model river overland flow and (ii) to take advantage of FullSWOF code properties for overland flow simulation in urban environment.