3-D Tidal Modeling of Cumberland Basin

A numerical model is used to describe the hydrodynamic regime of Cumberland Basin at the head of the Bay of Fundy, both as naturally occurring and as modified by a tidal power plant. The model is three dimensional to describe the role of the vertical velocity structure in dispersion processes and sediment transport in the basin. It uses a fine grid (400 m) for the horizontal space dimensions and continuously represents the vertical by a superposition of Legendre polynomials. Natural conditions are simulated for the M2 tide as well as a fortnightly cycle. Computed bottom stress distributions for natural conditions are relatively uniform, indicating that the basin may have reached an equilibrium configuration with respect to the bottom materials available in the area. Simulations of a tidal barrage operation for the M2 tide show drastic changes in both the residual current patterns and the bottom stress distribution. The nature and implications of these changes are discussed.