Comparison of two modelling strategies for 2D large-scale flood simulations. (December 2021)

• Record Type: Journal Article
• Authors: Dazzi, Susanna; Shustikova, Iuliia; Domeneghetti, Alessio; Castellarin, Attilio; Vacondio, Renato
• Is Part Of: Environmental modelling & software. Volume 146(2021)
• Publication Date: 2021-12
• Subjects: 2D inundation models -- Shallow water equations -- Local inertial approximation -- Model benchmarking -- Hydraulic simulations -- Parallel computations; Environmental monitoring -- Computer programs -- Periodicals; Ecology -- Computer simulation -- Periodicals; Digital computer simulation -- Periodicals; Computer software -- Periodicals; Environmental Monitoring -- Periodicals; Computer Simulation -- Periodicals; Environnement -- Surveillance -- Logiciels -- Périodiques; Écologie -- Simulation, Méthodes de -- Périodiques; Simulation par ordinateur -- Périodiques; Logiciels -- Périodiques; Computer software; Digital computer simulation; Ecology -- Computer simulation; Environmental monitoring -- Computer programs; Periodicals; Electronic journals; 363.70015118
• DOI: 10.1016/j.envsoft.2021.105225
• Languages: English
• ISSNs: 1364-8152

Abstract

Abstract: In this paper, two emerging strategies for the reduction of the computational time of 2D large-scale flood simulations are compared, with the aim of evaluating their strengths and limitations and of suggesting guidelines for their effective application. The analysis is based on two state-of-the-art raster flood models with different governing equations and parallelization strategies: PARFLOOD, a GPU-accelerated code that solves the fully dynamic shallow water equations, and LISFLOOD-FP, which combines a parallel implementation for CPU with simplified equations (local-inertial approximation). The results of two case studies (a river flood propagation, and a lowland inundation) suggest that, at coarse grid resolutions, the parallelized simplified model LISFLOOD-FP can represent a good alternative to fully dynamic models in terms of accuracy and runtime, while the GPU-parallel code PARFLOOD is more efficient in case of high-resolution simulations with millions of cells, despite the greater complexity of the numerical scheme. Highlights: Long runtimes of 2D hydraulic simulations require effective speed-up strategies. Emerging models exploit parallelization or simplification of shallow water equations. The LISFLOOD-FP and PARFLOOD codes are compared as regards accuracy and runtimes. At high-resolution, PARFLOOD outperforms the simplified parallel LISFLOOD-FP. For coarse grids, LISFLOOD-FP is a good alternative to a more complex model.