杭州湾南岸镇海段水下岸坡冲淤动态研究

发布时间：2018-03-24 12:10

本文选题：冲淤动态　切入点：水下岸坡　出处：《浙江海洋大学》2017年硕士论文

【摘要】：杭州湾南岸镇海段海域位于宁波与舟山群岛之间,金塘大桥西岸位于研究区内。研究该岸段海岸历史演变及现代变化的基本特征(如水下岸坡的平面冲淤变化、典型剖面的冲淤形态调整等),能够更好地认识淤泥质港口岸线的发育变化历史、冲淤演变过程和工程环境效应,能够为港区的良好运营、水深维护及可持续发展提供必要的参考依据,为附近海域未来其他涉海工程的施工提供指导意见,尤其对于区域内杭州湾地区环线并行线G92N(杭甬高速复线)宁波段一期工程,本文亦可为其提供相关理论支持。同时也能够丰富河口海岸学的研究内容,为其他深水岸线资源的可持续开发与利用提供可借鉴的经验。本文在收集研究区域多个年份的海图和水深地形图的基础上,运用GIS技术,研究了镇海港区岸线变化、特征等深线分布及其水下岸坡的平面冲淤变化和典型剖面的冲淤形态调整,同时结合水文泥沙资料,从上述几个方面讨论分析了研究区域水下岸坡的冲淤动态趋势。结果表明:近54年来,杭州湾南岸镇海段附近海域潮滩和5m等深线以及水下浅滩总体均向海外移,潮滩外移幅度约334~1912m,年均外移速率约6.19~35.41m/a,5m等深线外移幅度约600~5700m,年均外移速率约11.11~105.56m/a。且研究区域附近海域总体上全部表现为淤积,平均淤积幅度为1.10m,年均淤积速率约2.04cm/a。可以认为,在近自然条件下,研究区总体上是冲淤平衡的,但受围涂促淤丁坝等人类工程的影响,近年来淤积速率明显加快。同时,三峡水利工程在一定程度上会减少研究区内的泥沙量,从而在一定程度上降低淤积速率,甚至使局部区域发生冲刷。此外,受跨海桥梁的阻水作用影响,研究区内部分泥沙落淤,桥墩附近可能出现局部冲刷。潮滩仍在向海发育,但随着发育过程的进展,其速率趋于减缓,在现有岸线不受影响的情况下,未来将会达成平衡。
[Abstract]:The sea area of Zhenhai section on the south coast of Hangzhou Bay lies between Ningbo and Zhoushan Islands, and the west bank of Jintang Bridge is located in the study area. The adjustment of scour and silt shape in typical sections can better understand the history of development and change of shoreline in muddy ports, the evolution process of scouring and silting and the environmental effects of engineering, and it can be used for the good operation of port areas. The maintenance of water depth and the sustainable development provide the necessary reference basis for the construction of other sea related projects in the nearby sea area, especially for the first stage of the Ningbo section of the parallel line G92N (Hangzhou-Ningbo Expressway) in the Hangzhou Bay area. This paper can also provide relevant theoretical support, and enrich the research content of estuarine and coastal science. This paper, on the basis of collecting the charts and bathymetric topographic maps of several years in the study area, applies GIS technology to study the changes of shoreline in the coastal area of Zhenhai Port, which can be used for reference in the sustainable exploitation and utilization of other deep-water shoreline resources. The distribution of characteristic isobath and the change of plane scour and deposition of underwater bank slope and the adjustment of scour and deposition form of typical section, and the combination of hydrological and sediment data, From the above several aspects, the dynamic trend of erosion and deposition of underwater bank slope in the study area is discussed and analyzed. The results show that in the last 54 years, the tidal flat, 5m isobath and underwater shoal in the Zhenhai section of the south coast of Hangzhou Bay have generally moved overseas. The average annual migration rate of tidal flat is about 6.19 ~ 35.41 m / a ~ 5 m isobath, and the average annual migration rate is about 11.11 ~ 105.56 m / a, and the average sedimentation range is 1.10 m and the average annual deposition rate is about 2.04 cm 路路a ~ (-1) 路a ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (12) m, respectively. Under the near natural conditions, the study area is generally balanced by erosion and siltation, but due to the influence of such human projects as confining and silting spur dikes, the sedimentation rate has been obviously accelerated in recent years. At the same time, the three Gorges Water Conservancy Project will, to some extent, reduce the amount of sediment in the study area. Therefore, to some extent, the sedimentation rate is reduced, and even the local area is scoured. In addition, due to the influence of the water blocking action of the bridge across the sea, some sediment in the study area may be silted, and local scour may occur near the pier. The tidal flat is still developing along the sea. However, with the progress of the development process, its rate tends to slow down, and the balance will be reached in the future when the existing shoreline is not affected.
【学位授予单位】：浙江海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U652.3;TV148.6

【相似文献】