No abstract

No abstract

The boat traffic associated with the accelerating urbanization of coastal areas has a significant impact on the health of coastal ecosystems. In otherwise typically quiescent intracoastal and estuarine waterways, the transient wave activity created by boat traffic generates intermittent bursts of higher flow velocities, accelerations, and stresses on the bed, vegetation, and both bivalve and coral reefs. Although boat wakes may have relatively small heights in deep water, they grow, steepen, and break as they shoal on sloping banks/beaches

PURPOSE:This technical note documents the sediment transport module and morphological module developed in the Boussinesq wave model, FUNWAVE-TVD. The sediment transport module is based on the quasi-steady flow assumption, which is believed to be a more appropriate model for predicting sediment transport in the swash zone and ship-wake-induced shoreline erosion. It includes the suspended sediment transport and bedload sediment transport. The morphological module calculates morphological evolution based on the sediment continuity equation. This technical note also provides model validations and an example for simulating ship-wake-induced sediment transport and morphological changes. This technical note is considered an interim product that will eventually be turned into a full technical report with more validation and verification work, in particular for the case of cohesive sediment transport and morphology change. INTRODUCTION: Two types of sediment transport models have been developed under the FUN-WAVE model framework. Long and Kirby (2006) developed a coupled Boussinesq/bottom boundary layer model for surface wave-induced sediment transport and morphological changes in near-shore regions. The model is based on the curvilinear version of FUNWAVE (Shi et al. 2001)and calculates the bed-load and suspended-load transport rates using instantaneous bed shear stress in a generalized curvilinear coordinate framework. Recently, a sediment transport model for predicting nearshore seabed changes induced by co-seismic tsunamis has been developed by Tehranirad et al. (2016). The sediment transport model coupled with FUNWAVE-TVD (through multi-nesting from the Spherical coordinates to the Cartesian coordinates) successfully reproduced the deposition/erosion patterns in the Crescent City Harbor after the 2011 Tohoku tsunami. This model is based on the quasi-steady flow assumption and is particularly applicable to sediment transport induced by longer waves relative to wind wave periods.The model validations in Tehranirad et al. (2018) indicated that the quasi-steady flow-based sediment transport model is more accurate for predicting the morphological changes due to swash motion, compared with the bottom boundary layer-based sediment transport model, which is suitable for the surfzone. According to the wave characteristics of ship wakes, the quasi-steady flow-based sediment transport model such as in Kobayashi and Tega (2002) is believed to be a more appropriate model for simulating ship-wake-induced shoreline erosion because shoreline erosion occurs at the swash zone or river banks. In this study, the focus was on the ship-wakeinduced sediment transport and shoreline erosions and thus re-implemented the sediment transport and morphological modules in the present version of FUNWAVE-TVD, which has already included the ship-wake generation.The sediment transport model implemented here solves an advection-diffusion depth-averaged sediment concentration equation. It uses van Rijn's (1984) pickup function to calculate sediment ero...

No abstract