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

Abstract This study investigates how varied coastline strategies and rising mean‐sea‐level influence tidal distortion along the open coast of the Yellow Sea shelf. The major contributors to tidal distortion were first identified. Then, the primary tidal constituents causing changes in tidal propagation and distortion in response to shoreline reconstruction management and near‐future sea‐level‐rise (SLR) were determined. The intrinsic mechanisms causing tidal duration asymmetry (TDA) were investigated and found to differ in various types of coastal systems. Specifically, the nonlinear tidal interaction between M 2 /M 4 , M 2 /S 2 /MS 4 and K 1 /O 1 /M 2 are the top three dominant contributors to TDA. The interactions between M 2 /M 4 and M 2 /S 2 /MS 4 are most sensitive to different coastline configurations and produce the largest evolution in tidal distortion. Two primary factors are (i) the location of the amphidromic point of the semidiurnal tides in the deep ocean, which controls the M 2 and S 2 energy fluxes into embayment, and (ii) the nondimensional amplitude ( A / h ), which importantly indicates tidal nonlinearity and determines shallow tide generation. For the coast with a progressive tidal system, tidal distortion and shallow‐water tide genesis depend mainly on the influx of semidiurnal tides from offshore, which is controlled by the position of the M 2 amphidrome. For a coast with quasistanding tidal behavior, however, the scales and positions of tidal flats and shoals play vital roles in tidal distortion and the genesis of shallow‐water tides. Model simulations suggest that hardened shoreline or SLR could dampen the advection and bottom dissipation, thus reducing tidal distortion.