| 近三十年长江口横沙岛潮滩湿地地貌演变对河口工程的响应 |
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| 引用本文： | 魏伟,骆蓓菁,丁玲.近三十年长江口横沙岛潮滩湿地地貌演变对河口工程的响应[J].吉林大学学报(地球科学版),2021,51(4):1193-1203. |
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| 作者姓名： | 魏伟 骆蓓菁 丁玲 |
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| 作者单位： | 上海勘测设计研究院有限公司, 上海 200335 |
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| 基金项目： | 上海市科委科研计划项目（18DZ1206600）；中国长江三峡集团有限公司科研项目（201903173） |
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| 摘 要： | 由于人类活动的不断加剧和入海泥沙的日益减少，我国部分河口潮滩湿地已面临严重的侵蚀退化风险，给沿岸城市发展带来巨大威胁，实现河口潮滩湿地的科学管理和合理利用极为紧迫。本研究利用1990—2017年多期长江口深水航道北导堤工程与横沙岛成陆-促淤工程前后区域海图地形数据，使用ArcGIS地理配准、等深线数字化、数字高程模型建立和叠加分析等功能分析长江口横沙岛潮滩湿地地貌、等深线形态与地形冲刷-淤积厚度的时空变化过程。研究结果表明，长江口深水航道北导堤工程与横沙岛成陆-促淤工程的实施，改变了横沙岛潮滩湿地周边水域的水文泥沙动力条件，使得地貌冲淤时空特征发生变化：1）深水航道北导堤工程与横沙岛成陆-促淤工程的实施极大地推动了特征等深线的向外延伸，其中0、2和5 m等深线包络面积年均最大增长率（2009—2013年）分别是工程前（1990—1998年）的42.13、280.73和235.65倍，0~1、1~2、2~3、3~4及4~5 m等深线包络体积整体呈现1990—1998年、1998—2009年、2009—2013年增加，2013—2017年较为明显减少，潮滩湿地"长高不长大"的趋势；2）冲刷-淤积频率特征表现为工程前微淤（1990—1998年）、工程后微淤（1998—2009年）、淤积增加明显（2009—2013年）及微冲（2013—2017年），长江入海泥沙通量的减少对2 m等深线以深区域的潮滩发育可能产生一定影响。
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| 关 键 词： | 河口潮滩湿地 特征等深线 地貌冲淤 工程影响 横沙岛 长江口 |
| 收稿时间： | 2020-05-05 |
Three Decadal Morphodynamic Responses of Hengsha Island Tidal Flat Wetland to Adjacent Engineering in Yangtze Estuary |
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| Wei Wei,Luo Beijing,Ding Ling.Three Decadal Morphodynamic Responses of Hengsha Island Tidal Flat Wetland to Adjacent Engineering in Yangtze Estuary[J].Journal of Jilin Unviersity:Earth Science Edition,2021,51(4):1193-1203. |
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| Authors: | Wei Wei Luo Beijing Ding Ling |
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| Institution: | Shanghai Investigation, Design & Research Institute Co. Ltd, Shanghai 200335, China |
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| Abstract: | In recent years, with the intensification of human activities and reduction of sediment into the sea, some estuarine tidal flat wetlands in our country have been facing serious erosion and degradation, which poses a huge threat to the development of coastal cities. Therefore, the scientific management and rational use of estuarine tidal flat wetlands are extremely urgent. In this study, the regional chart topography data before and after the multi-phase of Yangtze Estuary deepwater channel north dyke project and the Hengsha Island land forming and silting promoting project from 1990 to 2017 were used to analyze the evolution of the wetland landforms in Hengsha Island, and the ArcGIS geographic registration, contour digitization, digital elevation model establishment, and overlay analysis were used to analyze the landform isobaths changes in morphology, terrain erosion-sediment thickness, and spatiotemporal changes of Hengsha Island. The result indicates that the implementation of the north guide dike project of the deepwater channel of Yangtze Estuary and the land forming and silting promoting project of Hengsha Island has changed the hydrological and sediment conditions to certain extent in the waters around the tidal flat wetlands of Hengsha Island, and its status of landscape erosion and deposition:1) It has greatly promoted the outward orientation of the characteristic isobaths. The maximum annual growth rate of 0, 2,and 5 m isobaths envelope area (2009-2013) is 42.13, 280.73, and 235.65 times that of the project (1990-1998). The overall envelope volume of 0-1, 1-2, 2-3, 3-4, 4-5 m isobaths shows an overall increase in 1990-1998, 1998-2009, and 2009-2013, and the tidal flat wetland shows a trend of "growing up but not extending". 2) The frequency characteristics of erosion-deposition are micro-deposition before engineering (1990-1998), micro-deposition after engineering (1998-2009), significant increase in deposition (2009-2013), and micro-erosion (2013-2017). At the same time, the reduction of sediments from Yangtze Estuary into the sea may have produced a certain impact on the development of tidal flats below the 2 m isobaths. |
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| Keywords: | estuarine tidal wetland characteristic isobaths geomorphic erosion and deposition engineering effects Hengsha Island Yangtze Estuary |
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