Tidal Responses to Future Sea Level Trends on the Yellow Sea Shelf. Issue 11 (4th November 2019)

• Record Type: Journal Article
• Authors: Feng, Xi; Feng, Hui; Li, Huichao; Zhang, Fan; Feng, Weibing; Zhang, Wei; Yuan, Jinjin
• Is Part Of: Journal of geophysical research. Volume 124:Issue 11(2019)
• Page Start: 7285
• Page End: 7306
• Publication Date: 2019-11-04
• Subjects: changing tides -- sea level rise -- Yellow Sea shelf -- inundation -- coastline configuration -- coastal defense strategies; Oceanography -- Periodicals; 551.4605
• DOI: 10.1029/2019JC015150
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: Quantifying 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. Plain Language Summary: China has experienced rapid economic growth and irreversible pressures from sea level rise (SLR) in the eastern coastal region. To provide future coastal defense strategies, we conduct multiple experiments to simulate how tides evolve with future SLR scenarios as well as how tides respond to different coastline configurations. We found that the future SLR can adjust the entire tidal system and control how much tidal energy flows into the local area from the deep ocean. Whether to build up or maintain a seawall for coastal defense depends on local conditions. By preserving the natural coast and removing the impermeable seawall from the radial sand ridges of China, tidal waves become more progressive on the shoals. Key Points: Tidal change remains linear under a 2.0‐m sea level rise within which a large spatial similarity was achieved on the Yellow Sea shelf Displacement in the amphidromic point on the northern Yellow Sea shelf dominates the tidal range evolution for the Jiangsu coastal area The seawall of Jiangsu with SLR enlarges the tidal range where the tide is reflective but functions opposite where the tide is parallel to the coast