Influence of Potential Future Sea-Level Rise on Tides in the China Sea

This study investigates the diurnal and semidiurnal tidal responses of the entire China Sea to a potential rise in sea level of 0.5-2 m. A modified two-dimensional tidal model based on MIKE21 is primarily configured and validated for the present situation; then, three (0.5, 1, 2 m) sea-level rise (SLR) scenarios are simulated with this model. The predicted results show that the principal lunar semidiurnal (M-2) and diurnal (K-1) tidal constituents respond to SLR in a spatially nonuniform manner. Generally, changes of M-2 and K-1 amplitudes in shallow waters are larger than those in the deep sea, and significant tidal alterations mainly occur in the Bohai and Yellow seas, Jianghua Bay, Hangzhou Bay, Taiwan Strait, Yangtze River estuary, Pearl River estuary, and Beibu Bay. Possible mechanisms further discussed for these changes mainly relate to bottom friction decreasing, amphidromic point migration, and resonant effect change. Additionally, simulated changes in M-2 and K-1 amplitudes in response to three SLR scenarios imply that M-2 amplitude changes are proportional to the magnitude of SLR, whereas this proportionality does not hold for K-1 amplitudes. Identifying the response of tides in the China Sea to SLR not only increases our knowledge of tidal systems, but also assists in setting conservation requirements and management plans in coastal areas.