Modeling the hydrodynamics of a tidal inlet during storms

Abstract

Tidal inlets are strategic locations for the economic development and ecosystem well-being of barrier islands and coastal regions. Understanding of the processes that drive the hydrodynamics and morphology of tidal inlets is therefore needed to better manage sediment and infrastructure around these dynamic coastal features (Elko et al. 2020). Interaction of oceanic, estuarine, and atmospheric conditions make tidal inlets challenging to study, but it is known that the general circulation patterns of tidal inlets result from the balance of tidal, wind, and wave-induced currents (Bruun, 1978; Keulegan, 1967; de Swart and Zimmerman, 2009). In recent decades, numerical models and observations have been combined to better understand the effects of waves in water level modulation in bays and areas surrounding tidal inlets. Dodet et al. (2013), Irish and Cañizares (2009), Olabarrieta et al. (2011), Orescanin et al. (2014), and Wargula et al. (2018) found that waves can reduce the ebb jet of inlets and increase water levels in the inlet mouth and bays. During ocean storms, the enhanced interaction of tidal flows and waves result in bathymetric changes along the inlet’s main channel, ebb and flood deltas (Hopkins et al., 2018; Velasquez-Montoya et al., 2020) that in turn can modify circulation patterns after the storm. Most of the studies that have looked at the response of tidal inlets during extreme conditions have focused on storms that propagate through the ocean; however, in large bays storms can travel landward of tidal inlets resulting in water levels in the bay exceeding those in the ocean. This work explores the effects of a synthetic storm that resembles the conditions of a major hurricane passing landward of a tidal inlet. The goal of this study is to gain insights on flooding extent, change in currents, and wave modulation of ebb discharge by bay-side storms. These insights can inform management practices of lands adjacent to tidal inlets as well as sediment management strategies within the inlet channel(s).