Tidal Responses to Future Sea Level Trends on the Yellow Sea Shelf

Abstract

AbstractQuantifying how tides evolve with coupling between future sea level rise (SLR) and different coastline configurations is imperative for proposing appropriate coastal defense strategies. By using numerical models, we investigated tidal changes and determined a realistic trend of SLR on the Jiangsu coastal area and adjacent sea on the Yellow Sea shelf. A notable decrease in tidal range occurs in the northern shelf, and the tide increases mainly in the southern shelf. Tidal changes are of both signs, while the increase in sea level is unidirectional. Thus, the SLR effect on tide is not additive in all locations. We also explored the nonlinearity and spatial similarity in tidal range in response to the SLR considering uniform SLR scenarios with multiple levels and allowing inundation of the natural coastline. The patterns of change in tide evolution on the study domain remain linear until the SLR exceeds 2.0 m. Simulations and comparisons are further conducted between the responses of hardened and natural shoreline configurations to SLR. Hardened shoreline introduces both local and remote spatial variability in tidal responses. On the regional scale, SLR induces a shift in the tidal system in the offshore region, which controls the net energy flux into the embayment upon the coast. On the local scale, tidal dynamics are mainly a competition between net energy flux and tidal dissipation and are plausibly influenced by tidal reflection, which depends on whether a basin is tidally reflective.