摘要
为更好研究长江河口段平均海面的特性,建立了大通至长江口感潮河段的二维水动力数学模型,通过模拟径流与潮汐共同作用下的水动力过程,并设置上下游不同条件的对照组,分析了河口段平均海面的影响因子及响应规律。结果表明,长江河口段年平均海面A0值由上游径流和外海潮波共同作用产生,外海潮波给予了河道内平均水位一个沿程定值,而径流使得其产生了沿程衰减的趋势,这是河口段A0特征不同于外海的原因,也说明径流是其主要影响因子。A0只受径流和外海潮位的年平均值影响,而不受两者的年内变化影响。径流量的变化会导致上游A0值比下游发生更加显著的响应;外海A0值的变化会使沿程发生大致等量的变幅。未来全球海平面上升后,河口段A0也将上升相近幅度。
In order to study the characteristics of mean sea level at Yangtze River estuary reach, a two-dimen-sional hydrodynamic model for the tidal reach of the Datong-Yangtze River estuary was established. By simulatingthe hydrodynamics in response to runoff and tides and setting different upstream and downstream boundaries, the in-fluence factors and responses of A0 at Yangtze River estuary reach were analyzed. The results show that, the A0 atYangtze River estuary reach is co-produced by runoff and tidal action. The offshore level gives a constant value tothe A0 along the estuary reach; meanwhile, the discharge of runoff produces the decay trend along the way to it, it ′ sthe reason why the characteristics of the A0 along the estuary reach is different from in offshore area, and it provesthat the runoff is the main influence factor. The A0 in estuary is only affected by the average level in offshore and theaverage discharge of runoff, but not by the change of runoff and offshore tide during a year. The average discharge ofrunoff during a year will affect the A0, and the upstream sites are more sensitive than downstream; the offshore A0 will produce a similar amount of change to it. With the global sea level rise, the A0 in estuary will rise by a similar tooffshore.
出处
《水道港口》
2015年第3期204-209,共6页
Journal of Waterway and Harbor
基金
国家重点基础研究发展计划(973计划)课题:长江口海域水动力过程与生态系统演变机制(2010CB429001)
国家科技支撑计划(水沙变异条件下荆江与长江口北支河道治理关键技术研究)课题:长江口北支建闸技术研究(2013BAB12B05)
江苏省水利科技项目:风暴潮耦合影响下长江镇扬河段水位预报技术研究(2012036)
关键词
数值模拟
平均海面
海平面上升
长江河口
numerical simulation
mean sea level A0
sea level rise
Yangtze River estuary reach
