Effects of sea-level rise on tides and sediment dynamics in a Dutch tidal bay

Abstract

Sea-level rise (SLR) not only increases the threat of coastal flooding, but may also change tidal regimes in estuaries and coastal bays. To investigate such nearshore tidal responses to SLR, a hydrodynamic model of the European Shelf is downscaled to a model of a Dutch coastal bay (the Oosterschelde, i.e., Eastern Scheldt) and forced by SLR scenarios ranging from 0 to 2 m. This way, the effect of SLR on tidal dynamics in the adjacent North Sea is taken into account as well. The model setup does not include meteorological forcing, gravitational circulation, and changes in bottom topography. Our results indicate that SLR up to 2 m induces larger increases in tidal amplitude and stronger nonlinear tidal distortion in the bay compared to the adjacent shelf sea. Under SLR up to 2 m, the bay shifts from a mixed floodand ebb-dominant state to complete ebb dominance. We also find that tidal asymmetry affects an important component of sediment transport. Considering sand bed-load transport only, the changed tidal asymmetry may lead to enhanced export, with potential implications for shoreline management. In this case study, we find that local impacts of SLR can be highly spatially varying and nonlinear. The model coupling approach applied here is suggested as a useful tool for establishing local SLR projections in estuaries and coastal bays elsewhere. Future studies should include how SLR changes the bed morphology as well as the feedback effect on tides.

An Analysis of the 8.85- and 4.42-Year Cycles in the Gulf of Maine

“…Figure 9 shows the long-term linear trend (the IPs is equal to 0 and the parameter is equal to 2) of the total sea levels at the four stations, and they increased evidently. Some papers have noticed the effect of SLR on the tide, and the localized responses have been explored on the European shelf [34][35][36]. Besides, the coastal defense could exacerbate the increases in the tidal range induced by the SLR, and flooding over land induces damping of the tidal amplitude [37][38][39].…”

On the Role of Anthropogenic Activity and Sea‐Level‐Rise in Tidal Distortion on the Open Coast of the Yellow Sea Shelf

“…For example, in Newport Bay, California, USA, SLR has been reported to reverse tidal asymmetry from ebb dominance to flood dominance (Guo et al, 2018). Similarly, Jiang et al (2020) found that 2-m SLR could shift the tidal asymmetry in a Dutch estuary from a mixed flood/ebb-dominant status to an ebb-dominant status. Along the western Korean coast and the coast of Jiaogzhou Bay, China, the tidal asymmetry trend was found to be inhomogeneous at different stages of one large-scale reclamation project (Gao et al, 2014;Suh et al, 2014).…”

Response of tidal flow regime and sediment transport in North Male' Atoll, Maldives to coastal modification and sea level rise

“…Driven by their importance to the coastal zone, the response of tidal dynamics and sediment to future sea level rise scenarios as well as to coastal modification has been considered in various studies targeting different locations around the world, ranging from marginal seas such as the Bohai Sea (e.g., Pelling et al, 2013), shelf seas such as the North-West European continental shelf (e.g., Ward et al, 2012) and estuaries and bays such as the Eastern Scheldt estuary (e.g., Jiang et al, 2020). However, the response of sediment distribution in large coral atolls to anthropogenic pressures such as land reclamation and coastal modification remains poorly studied and is generally restricted to very small patch reefs for a variety of reasons including remoteness and lack of data.…”

“…Studies (e.g., Holleman and Stacey, 2014;Jiang et al, 2020) have shown that the response of the tides to changing physical characteristics such as bathymetry and coastline modification can vary significantly in different areas depending on the local geological setting. According to these studies the response in some environments is more complex than others due to the effects of processes such as shoaling, damping and resonance.…”

“…(c). The importance of the distance to boundary has been highlighted in several studies includingJiang et al (2020), who demonstrated the necessity to include adjacent regions when studying regional scale tidal response to factors such as SLR. Similar issues have been discussed in the context of altering the tidal dynamics within a boundary forced tidal domain due to the installation of tidal energy devices within a model setup(Adcock et al, 2011), the recommendation being to locate open boundaries beyond the 11 https://doi.org/10.5194/os-2020-80 Preprint.…”