A Depth-Averaged 2-D Analysis of Fish Habitat Suitability Impacted by Vegetation and Sediment

Two-dimensional habitat modeling is becoming more and more necessary because the eco-hydraulic information in longitudinal and lateral dimensions in rivers and wetlands is essential for habitat evaluation, especially in habitat restoration projects. A general habitat module based on the FVM-based CCHE2D model has been developed to reproduce and quantify the complex characteristics of flow in a river reach for better assessment of habitat. The established model has been applied to study the effect of large wood structures on fish habitat in the Little Topashaw Creek and the effect of sediment transport on fish habitat in a reach in the Mississippi River. Generally, the change of bed topography due to the addition of large wood structures can redistribute the water depth and flow velocity, which influence the distribution of habitat area. The usable habitat area is underestimated if vegetation is not considered, while it may be overestimated if sediment transport is not considered.