渤海湾西部与南部海岸线和潮滩演变及其影响因素

COASTLINE CHANGES AND TIDAL FLAT EVOLUTION IN WEST AND SOUTH PARTS OF BOHAI BAY AND AFFECTING FACTORS

通过对渤海湾西部和南部自1975年至2010年之间不同时期卫星遥感影像的研究发现,近40年来研究区海岸形态发生了巨大的变化,海岸线长度呈现先轻微减小后大幅增加的状态,很多岸段岸线向海有较大推进,最远达20余千米;潮滩呈向海淤涨趋势,渤海湾西部年平均淤积速率比南部略大;岸线的向海推进以及潮滩的不断淤长,使得渤海湾面积持续减小。目前,研究区沿岸除存在部分河口型自然海岸线外,几乎全部变为人工海岸线。从沉积物来源、水动力变化以及人类活动等方面对研究区海岸线和潮滩演变的影响因素进行了分析,指出这些演变是自然因素和人类活动影响共同作用的结果,随着开发利用海洋活动的增加,人类活动的影响在研究区海岸带环境演变中所起的作用越来越明显和重要。

Based on the satellite images for the west and south parts of the Bohai Bay in different periods, we summarized in this paper the great changes of shoreline in the past forty years. The length of the shore- line decreased slightly first and then increased during the period of 1984 and 2010. The shoreline extended seaward, and in some places, it might expand up to a maximum of more than 20 kilometers. The tidal flat was expanding from 1984 to 2000, and the growing rate in the south was faster than that in the west. The area of the Bohai Bay has been decreasing due to shoreline advancing. Almost all the shoreline of the Bohai Bay have turned into artificial except for some estuary shorelines since 2010. Tidal flat evolution has been studied from the viewpoints of sediment source, hydrodynamic change and human activities. The study showed that the shoreline and tidal flat evolution in the area was affected by both the natural environment and the human activities. The influence of human activities is obviously increasing with time.