Three-dimensional hydrodynamic simulation of tidal flow through a vegetated marsh area

Simulation of tidal flow in an estuarine marsh area is challenging because of resistance from spatially and temporally varied vegetation. This study simulated the tidal flow in the Davis Pond marsh area near New Orleans, Louisiana, using an open source program. To quantify the time-varying roughness coefficient, four empirical equations for calculating Manning's roughness coefficient were incorporated into the program in addition to two options offered by the program to calculate the Chezy's coefficient and one option to use the modified momentum equations and the k-ε turbulence model. Results showed that the time-varying roughness coefficient equations accounting for both the degree of submergence and the vegetation frontal area gave the closest matches with the observed data.