黄骅港地区岸线变迁及滩面—浅海区形态变化
SHORELINE SHIFTING AND MORPHOLOGY CHANGES OF THE TIDAL FLAT-SHALLOW SEA AREA OFF HUANGHUA HARBOR
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摘要: 在黄骅港附近岸段开展了岸线实地调查和潮间带年际监测,并结合历史资料和图鉴对比等手段,对黄骅港两侧岸线变迁及滩面-浅海区形态变化过程及其趋势进行了综合研究。结果显示:(1)黄骅港附近的岸线(老狼坨子岸段、大口河岸段)在过去50余年间普遍经历了岸线的蚀退过程。但进入20世纪80年代、特别是90年代黄骅港建设以来,建港及围海造陆工程使老狼坨子-冯家堡段的海岸线人为向海推进,而大口河岸段因人类活动较少、以及黄骅港防砂堤对沿岸流的阻隔,其岸线仍基本保持蚀退状态。(2)黄骅港建港对北侧的老狼坨子潮间带影响明显,造成该区现代沉积作用极为活跃,2004-2006年的滩面监测结果显示,其总体上保持淤高的趋势。南侧的大口河潮间带,2005-2007年的滩面监测结果显示,潮间带上部未见明显的变化、潮间带下部明显淤高。与80年代数据对比显示,这两个滩面的坡度均变缓。(3)近30年来,黄骅港海域河流作用日益减弱,海洋动力不断增强,塑造了废弃三角洲中-晚期地貌组合和潮道-泻湖沉积体系。1995年黄骅港建港以来,海洋水动力发生局部变化,并参与了对部分浅海区海底形态的塑造,但现有的数据表明,其影响仅限于潮间带和港口-航道防砂堤附近。Abstract: Shoreline surveys were carried out on the coastal zone near Huanghua Harbor.Two annual monitoring intertidal cross sections were launched on both sides of the Port. Combined with historical data and through illustrations comparison,the shoreline shifting and morphology changes of the tidal flat-shallow sea area were studied comprehensively.Results show that:(1)in the past 50 years,the shoreline near Huanghua Port(Laolangtuozi and Dakouhe coastal zone)has experienced a widespread retreat due to erosion.However,starting from 1980s,especially since the 1990s,the construction of Huanghua Harbor and Bohai New Area have made the shoreline moved forward towards the sea from Laolangtuozi to Fengjiapu.On the contrary,the shoreline around Dakouhe have remained retreating state because there is lack of human activities,and the Huanghua Port acts as a barrier to break the longshore current.(2)Huanghua Port construction has resulted in a high-rate sedimentation on Laolangtuozi in the north side of the harbor;the Dakouhe tidal flat in the south side of the Harbor,howerver,has no apparent change happened in the upper part,and siltation has only happened in the lower part based on the data from 2005 to 2007.Compared with the data of 1980s,it suggests that the slope of the tidal flat has become smaller.(3)In the past 30 years,with the decrease in river process and the increase in marine hydrodynamics,a middle-late stage abandoned delta and a tidal channel-lagoon system have been formed.Since 1995, with the construction of Huanghua Harbor,the marine hydrodynamic system has changed locally to be a force in shaping the morphology of shallow sea area,but the available data indicate that the impact is limited to the north tidal flat and the sea area near the sand embankment of the port.