A three-dimensional model of flow dynamics around paired deflectors for fish habitat enhancement

摘要

Schemes to restore fish habitat in rivers often involve installing instream structures such as current deflectors to create and maintain riffle-pool sequences. To improve the success rate of the many restoration schemes that fail or require costly maintenance, we need to develop tools such as numerical modeling to test scenarios prior to the implementation of structures. The objective of this research is to use a three-dimensional numerical model to characterize flow dynamics and sediment transport around paired deflectors used to enhance fish habitat in a natural river. Calibrating and validating such a model requires accurate measurements of these parameters in the natural river. Particle Image Velocimetry (PIV), typically used in laboratory flumes, was used to obtain detailed velocity measurements at the surface. These data serve to validate the 3D model of the study reach. It is hoped that this model will help maximizing deflector efficiency and success rate for future implementation.