Coupling 1D river and 2D floodplain for modelling fluvial inundations

Details

Supervisors

Hanert, Emmanuel ; Lambrechts, Jonathan

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil mécanicien, à finalité spécialisée

Abstract

With the escalating impact of river floods attributed to global warming, it has become imperative to adapt our lands accordingly. The construction of retention areas and the preservation of floodplains offer promising solutions in this regard, necessitating the use of numerical modeling to understand the dynamics of river flooding. In this thesis, we introduce a discontinuous Galerkin explicit method that effectively couples a 1D river model with a 2D floodplain representation. The exchange of mass is facilitated through the weir equation, employing lateral coupling between linear 1D elements and triangular 2D elements that accurately handle wetting-drying fronts. To validate the model, we conduct laboratory-like test cases, comparing the results with those obtained from a fully constructed 2D model. Furthermore, we perform a more realistic test on a bifurcation, which convincingly assesses the peak flow in the river. Notably, our model offers a significant time advantage while delivering satisfactory results in the study of river floods.