Interactions of Waves, Tidal Currents and Riverine Outflow and their Effects on Sediment Transport (RIVET II)

Studying the mixing of riverine freshwater and coastal water is the fundamental step to further understand the balance of a coastal/estuarine ecosystem (e.g., Hickey et al. 2010), seabed properties, sediment budgets (Gelfenbaum & Kaminsky 2010), and the sustainable management of the fluvial-estuary habitat (e.g., damming, dredging). The nearfield of a river plume represents an energetic environment because it involves the lift-off and subsequent lateral spreading of the freshwater outflow. As the lateral spreading must cause flow acceleration, the plume near field is highly turbulent (Hetland 2005; MacDonald et al. 2007) and may be dominated by locally generated shear instabilities (Geyer et al. 2010). With improved sensor and computing technology, recent field and numerical studies provided significant insights into the complex hydrodynamics near the plume lift-off zone and nearfield (e.g., MacDonald et al. 2007; Kilcher & Nash 2010; Elias et al. 2012). However, researchers are only beginning to understand how the near field plume dynamics affect the delivery of sediments. For instance, high level of suspended sediment concentration is often observed in the plume nearfield (Spahn et al.