崇明岛形成的历史过程

The Historical Formation of Chongming Island

本文根据2 0世纪80年代新发现的滨岸沙带,对唐武德年间成洲的东沙进行准确定位,然后以此为基础,论证崇明岛的基本框架和南、北支和南、北港分流,形成于元至元十四年稍前。明末清初之际,崇明岛完成大型沙洲合并过程,东西已达1 4 0余里,基本接近目前崇明岛长度。与此同时,支分已达40 0年的南北港,则因沙洲并岸而消失,南支江面随之展宽。1 3 5 2 -1 5 86年崇明城五次迁徙,是潮灾引起崇明岛冲淤变化的结果。在建的上海长江大桥陈家镇引桥,位处崇明岛最古老的东沙,基础坚实可靠,但冲淤变化永远不会停息,整个崇明岛均应密切注意潮灾的影响。

Based on the discovery of the littoral sandbar in 1980s,this paper manages to locate the Dongsha formed in the Tang Dynasty,and further points out that the framework of Chongming Island was formed in early Yuan Dynasty.And in late Ming Dynasty,its main sandbars merged together with a parallel length of 140 li,ronghly the same with that of today's Chongming Island.Meanwhile,the north and the south harbors,which had been separated for 400 years,however disappeared as sandbars joined each other.