The coast from the Zhangweixin River mouth to the Tuhai River mouth along the west coast of the Bohai Sea was stable and showed a straight coastline during the period of 1128-1904. The distributary channel of the Yellow River shifted to the east of the Tuhai River mouth and the land expanded to the north. A bay was gradually formed during 1904-1929. While the distributary channel of the Yellow River shifted to the middle of the Yellow River delta during 1934-1976, the land expanded further to the north and a wide "V"-shaped open bay was finally formed from Qikou of Hebei Province to the middle of the Yellow River delta. The Tuhai River mouth is just located at the apex of the wide "V"-shaped open bay. The coast from the Zhangweixin River mouth to the Tuhai River mouth is close to the apex and faces to the northeast strong winds, which occasionally induces strong storm tides. Comparing with those before 1904, the tidal range increases, the spring high tide level becomes higher, and much higher water level occurs in the storm tides. The storm tides and waves result in strong erosion, coastline retreat, very developed tidal channel system and remnant alluvium islands in the supratidal zone.%公元11-1099年漳卫新河口至徒骇河口海岸,除了初期的后退和1034-1099年的进积,大多数时间处于稳定状态,1099-1904年,除了1099-1128年的后退,长期处于稳定状态,大口河岛和王子岛贝壳堤是公元11年以来长期形成的.1904 1929年黄河在徒骇河口东入海,陆地向海推进14 km以上,岐口至黄河三角洲西部海岸初步形成一个内凹的开放海湾,1934-1976年黄河在三角洲中部入海,陆地进一步向海突伸,岐口至黄河三角洲中部之间宽阔的“V”形海湾最后形成.徒骇河口位于湾顶,漳卫新河口至徒骇河口这段海岸面对引起风暴潮的东北大风,和1904年以前相比,潮差增大,平均高潮位和大潮高潮位升高,在风暴潮时大幅增水,海水沿着徒骇河、马颊河、漳卫新河口等诸河流漫溢,落潮流汇聚入河流,在波浪和潮流的共同作用下,海岸侵蚀后退,在潮上带潮沟发育并形成若干侵蚀残留冲积岛.20世纪80年代的海岸线、密集潮沟系统和侵蚀残留冲积岛是1904年以后逐渐形成的,这是平原海岸轮廓短期内发生大变化,使得潮汐环境大变化,导致海岸巨大变化的一个很好实例.由于世界上其它平原海岸不可能在70 a多(1904-1976年)的时间内海岸轮廓发生如此大的变化,这个实例也是很独特的.
展开▼
