近60年来崇明岛东部淤涨速率初探

发布时间：2018-02-11 16:10

  本文关键词： 崇明岛东部 大堤 淤涨速率 长江水沙 围垦　出处：《长江流域资源与环境》2017年05期 　论文类型：期刊论文

【摘要】：崇明岛作为我国最大的河口冲积岛,其形成发育与长江来水来沙息息相关。历史上就有崇明岛围垦筑堤的记载,近60年来崇明岛东部地区所筑大堤主要有54大堤、64大堤、68大堤、92大堤和98大堤。选取正东、东北、东南不同方向的4个断面,以大堤位置代表所筑年份海岸线位置,对崇明岛东部淤涨速率及滩地淤涨面积变化进行计算,结果表明:(1)近60年来崇明岛东部整体淤涨速率约为200 m/a,淤涨面积年均增长率为2.80 km~2/a;(2)不同断面上淤涨速率存在差别,其中正东方向断面上淤涨最快;(3)不同时段崇明岛东部各断面淤涨速率存在快慢变化。各断面上,20世纪90年代的淤涨速率均最大。对比发现,20世纪50~80年代崇明岛东部淤涨速率的变化趋势,与同期长江年入海泥沙量的变化趋势基本一致;但20世纪90年代,由于围垦强度加大,两者变化趋势不一致。以海堤研究岸线变迁的工作尚不多见,此方法将为研究长时间尺度的岸线变迁提供借鉴。
[Abstract]:As the largest estuarine alluvial island in China, the formation and development of Chongming Island is closely related to the coming water and sand from the Yangtze River. In the last 60 years, the main embankments built in the eastern part of Chongming Island include 54 levees, 64 levees, 68 levees, 92 levees, and 98 levees. Four sections in different directions, Zhengdong, northeast and southeast, are selected to represent the shoreline position of the year built. In the last 60 years, the siltation rate of the eastern part of Chongming Island is about 200 m / a, and the average annual growth rate of the area is 2.80 km2 / a ~ (2 / a)) there are differences in the rate of siltation on different sections, the results show that: (1) in the last 60 years, the siltation rate of the eastern part of Chongming Island is about 200 m / a. The velocity of siltation in the east of Chongming Island varies rapidly and slowly in different periods. The rate of siltation on each cross section is the largest in 90s of the 20th century. The comparison shows that the east of Chongming Island in the 1950s and 1980s has the highest rate of siltation. The changing trend of the rate of partial siltation, In 1990s, however, because of the increase of reclamation intensity, the change trend of the sediment quantity in the Yangtze River is not consistent. The study of shoreline changes by seawall is still rare, but in 1990s, because of the increase of reclamation intensity, the trend of the two changes is not consistent. This method will provide a reference for the study of shoreline changes on a long time scale.
【作者单位】： 华东师范大学河口海岸学国家重点实验室;
【基金】：国家自然科学基金项目(41471161)~~
【分类号】：P736.1
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本文编号：1503461