A Numerical Modelling of Nature-Like Fish Passage Using a 2D Shallow Water Model

Abstract

Flow around fish habitat structures (e.g., boulders, rocks) is of great interest, particularly for fish passage technology. Modelling such three-dimensional (3D) complex hydraulics associated with habitat structure using an industrial 2D code solving Saint Venant equations may appear at first as a challenge. The purpose of this study is to determine the ability of a 2D code (River2D) to model flow through rock-ramp type nature-like fish pass and its limitations. The model was tested based upon the comparison between numerous experimental measurements and numerical simulations. The impact of varying computational mesh discretization and model calibration parameters on the accuracy of reproducing fish pass hydraulics was investigated using the River2D model. The results demonstrate that 2D shallow water model, River2D, model can be a convenient way for the hydraulic engineer to help design a nature-like fish pass.