1D–2D coupling for river flow modeling

A shallow water-based model for river–floodplain interaction (SW12D for Shallow Water 1D–2D) is presented. The main channel and floodplain are discretized using 1D and 2D elements respectively. The proposed model provides an improved description of hydraulic phenomena over existing models by (i) including lateral momentum transfer between the main channel and the floodplain, (ii) taking the 2D nature of the flow into account within the 1D elements that describe the main channel. This allows for a better description of phenomena such as head losses due to channel bends and meanders, and meander shortcuts during floods.