Effects of reconstruction of variables on the accuracy and computational performance of upscaling solutions of the shallow water equations

This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accura...

Full description

Saved in:
Bibliographic Details
Published in:Journal of hydraulic research 2023-05, Vol.61 (3), p.409-421
Main Authors: Shamkhalchian, Alireza, M. de Almeida, Gustavo A.
Format: Article
Language:English
Subjects:
2D shallow water equations
Accuracy
Finite element method
finite volume
Flooding
Mathematical models
nested meshes
Reconstruction
Roughness
Shallow water
Shallow water equations
solution upscaling and downscaling
sub-grid
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accurate in space (i.e. piecewise linear reconstruction of variables) Godunov-type finite volume (FV) method, while the fine mesh is used to incorporate high-resolution topography and roughness into the solution. The accuracy and performance of the model were compared against a first-order version of the model recently proposed by the authors and a second-order conventional FV model using artificial and real-world test problems. Results showed that improved accuracy is delivered by the proposed model, and that at low-resolution meshes, the spatial reconstruction of variables of the numerical scheme plays a major role in the solution's accuracy.
ISSN:0022-1686
1814-2079
DOI:10.1080/00221686.2023.2201210