中国近海潮汐变化对外海海平面上升的响应

针对外海海平面上升对中国沿海潮波系统和潮汐水位可能带来的影响,通过西北太平洋潮波数学模型对边界海平面上升后潮波变化进行了数值模拟。研究发现边界海平面上升后,在无潮点附近东侧迟角增加,西侧迟角减小;无潮点北侧振幅增加,南侧振幅减小;辽东湾、渤海湾顶、辽东半岛东海域、海州湾至鲁南沿海、苏北沿海、台湾海峡至浙东沿海和南海平均潮差增加,海平面上升0.90 m后潮差最大增幅达0.40 m;长江口、杭州湾至对马海峡、朝鲜西海岸和莱州湾海域潮差减小。随着海平面上升量值的增加,渤海、台湾海峡潮差变化速率相对稳定,黄海、东海和南海站位变化速率有所变动;平均高水位的变化趋势与潮差一致;潮差增加的区域,高水位抬升幅度超过边界海平面上升幅度。海平面上升引起的高水位超幅变化,增加了沿海地区对风暴潮和其他灾害防护的风险。

Tidal response of sea level rise in marginal seas near China

A numerical model of the Northwest Pacific is developed to study tidal system and tidal level changes due to mean-sea-level rise in marginal seas near China. The results show that after mean-sea-level rise, phase lags are increased to the east and decreased to the west of amphidromic point. The amplitude is enhanced to the north and diminished to the south of amphidromic point. Due to mean-sea-level rises, the mean tidal range is enlarged in the Liaodong Bay, the upper reaches of Bohai Bay, seas east of Liaodong Peninsula, coast of Haizhou Bay to the south of Shandong province, the north coast of Jiangsu province, the Taiwan Strait to the east of Zhejiang province, and the South China Sea. The maximum range is 0.40 m after mean-sea-level rise 0.90m. The mean tidal range is reduced in estuary of Yangtze River, Hangzhou Bay to Tsushima Strait, the west coast of Korea, and Laizhou Bay. With the increase of sea level rise, tidal range varies with relatively stable rate in the Bohai Sea, Taiwan Strait, and it with fluctuation in the Yellow Sea, East China Sea and South China Sea. Variation of mean high water level is in accord with tidal range. It uplifts more over than the mean-sea-level in areas where tidal range raises. That means the risk would increase of coastal areas to protect storm surge and other marine disasters.