2D and 3D Flow Modeling of the Sacramento River Fremont Weir Section

Both 2D and 3D numerical modelling are carried out for flow hydraulics along the Fremont Weir section of the Sacramento River, California. The models predict flow features such as velocity, turbulence and flow acceleration, as well as the diverse hydraulic conditions present, which are inputs to the agent-based fish movement model to be carried out. Various model runs and comparisons are reported in order to shed light on: (a) difference of two different 2D models; (b) ability of 2D models in predicting velocity field in rivers with sharp bends; (c) difference between 2D and 3D models; (d) model performance in comparison with field data; and (e) the appropriateness of models under practical and complex river environment. The study provides additional 2D and 3D model verifications when applied to practical rivers; it also provides guidelines on how to use 2D and 3D models for river projects.