The impact of vegetation on hydrodynamics in Port Phillip Bay

Abstract

This study investigates the impact of submerged aquatic vegetation (SAV) on hydrodynamics and sediment transport in Port Phillip Bay (PPB), a large tidal embayment in southeastern Australia. A high-resolution coupled hydrodynamic–wave–sediment model (SCHISM-WWMIII) was developed and validated against tide-gauge and buoy observations. Two scenarios, with and without seagrass, were compared to quantify SAV effects. Results show that including SAV improves model accuracy, especially for water levels, with correlation coefficients exceeding 0.9 and biases reduced to below 0.1 m. Modest improvements are also observed in wave height simulations at vegetated sites. SAV notably enhances the accuracy..