ABSTRACT
A 3D numerical model (Delft3D) was used for morphodynamic modelling of a tributary of Stillwater creek, a clay bed urban stream in the city of Ottawa, Canada. A main focus of this project was predicting changes in river morphology as a result of a proposed culvert realignment and meander cut-off for river channel stabilization and habitat creation. Design criteria were principally based on the goals of reducing local velocities, bed and bank shear stress, and consequent erosion throughout the reach. The standard hydrostatic version of Delft3D was used, which employs the 2 D shallow water equations in layers, thus vertical velocity is calculated only from flow continuity. Momentum corrections are employed to estimate secondary circulation in bends. Despite these limitations, the results of this study suggest that the developed 3D numerical model produced a reasonable 3D flow field as well as the corresponding patterns of soil erosion and deposition in the studied creek. It was also demonstrated that the proposed restoration design could be useful for creek protection.
