海平面上升对长江口涨落潮历时差的影响

Impact of sea level rising on flood and ebb duration difference of the Yangtze River estuary

针对近年来全球变暖,海平面上升影响河口地区水文特性的问题,对海平面上升对长江口涨落潮历时差的影响进行研究。采用二维潮流数学模型的方法,模拟在长江口上游大通的洪枯季及年平均径流量条件下,海平面上升100 cm对涨落潮历时的影响。结果表明:海平面上升减小了长江口北支上半段、南支和南北港等中上游区域的涨落潮历时差,对靠近外海的北支末段和南北槽的涨落潮历时差影响很小。海平面上升加大了河口地区的涨潮动力,使长江口的涨落潮历时差有所减小,由此对长江口地区的盐水入侵和泥沙输运带来的影响必须引起重视。

Aiming at the problem of sea level rising caused by global warming affects the hydrological characteristics of the estuaries in recent years,we study the impact of sea level rising on the flood and ebb duration difference of the Yangtze River estuary.We apply a two- dimensional mathematical tidal current model to simulate the effect of 100 cm sea level rising on the flood and ebb duration difference of the Yangtze River estuary when the runoff conditions of Datong in the upper reach are flood season,dry season and annual average runoff.The results show that sea level rising reduces the flood and ebb duration difference in the upper and middle reaches of the north branch,the south branch,the north channel and the south channel of the Yangtze River estuary,and has little effect in the last part of the north branch,the north passage and south passage near the offshore area.Sea level rising increases the flood tidal momentum of the estuaries,which reduces the flood and ebb duration difference of the Yangtze River estuary.Therefore,its impact on saltwater intrusion and sediment transport in the Yangtze River estuary must be taken seriously.