荣成湾典型沙坝-潟湖海岸地貌演变研究  

Research on the coastal geomorphic evolution of the typical barrierlagoon system in Rongcheng Bay

作　　者：任宗海 余建奎 战超[1] 王伟 许国纯[1] 耿文倩 曹印 王庆[1] REN Zonghai;YU Jiankui;ZHAN Chao;WANG Wei;XU Guochun;GENG Wenqian;CAO Yin;WANG Qing(Institute of Coastal Research,Ludong University,Yantai 264025,China;Institute of Marine Geological Exploration,Shandong,Yantai 264004,China)

机构地区：[1]鲁东大学海岸研究所,山东烟台264025 [2]山东省海洋地质勘查院,山东烟台264004

出　　处：《海洋通报》2023年第3期290-302,共13页Marine Science Bulletin

基　　金：国家自然科学基金(41901006);山东联合基金(U1706220);山东高校青创科技团队(2020KJH002);山东省地矿局近海海洋地质调查与监测评价创新团队。

摘　　要：20世纪70年代末以来,荣成湾月湖沙坝-潟湖海岸地貌发生了巨大变化。研究沙坝-潟湖海岸地貌的演化过程可进一步掌握其演化规律,对保护和修复沙坝-潟湖海岸地貌体系具有重要的现实意义和理论依据。本文以1975-2021年47期遥感影像和1934-2014年4期不同时期测量的海图为数据源,通过遥感(Remote Sensing,RS)技术和地理信息系统(Geographic Information System,GIS)对月湖沙坝岸线进行提取,并用数字岸线分析系统对岸线变迁进行定量分析,最后通过构建水下岸坡数字高程模型(Digital Elevation Model,DEM)对不同时期的等深线进行提取。结果显示:(1)1975-2021年沙坝处于侧蚀变窄和切蚀变短的状态,坝尾内弯显著。1975年以来沙坝侵蚀后退较显著,从坝根到坝尾侵蚀速率逐渐增加。其中,1979-1986年沙坝侵蚀最严重,最大后退距离达95.7 m,平均蚀退速率为8.32 m/a。(2)1975-2021年,沙坝面积逐渐减少,潮汐通道逐年展宽。其中,1979-1986年沙坝面积急剧减少,平均减少速率为0.0142 km2/a。2021年与1975年相比,沙坝面积减少了约43%。2001-2014年潮汐通道的平均展宽速率为14.01 m/a,2015年后宽度突破300 m。(3)以1980年为转折点,1980年以前水下岸坡总体趋势为淤高变浅,等深线向海迁移。1980年后水下岸坡侵蚀增强,等深线向陆迁移。荣成湾月湖沙坝-潟湖海岸地貌的演变主要受人类活动及沿岸泥沙输移的影响。In Rongcheng Bay,tremendous variations have occurred in the Yuehu barrier-lagoon coastal landform system since the late 1970s.Studying the evolution process of barrier-lagoon coastal landform can further grasp its evolution law,which is helpful for the protection and restoration of the barrier-lagoon coastal landform system.It has important practical significance and theoretical basis.The study data sources comprised remote sensing images from 1975 to 2021 and sea charts measured during different periods(1934-2014).Based on remote sensing technologies and the digital shoreline analysis system,we extracted and quantitatively analyzed the transitions of barrier shorelines.We set up a digital elevation model of an offshore slope.On this basis,isobaths for different periods were extracted.The results showed that:(1)From 1975 to 2021,the barrier generally narrowed laterally and altered by shear shortening,and the barrier tail incurved significantly.From 1975,the barrier eroded strongly and retreated,and the erosion rate gradually increased from the root to the end;the most intense erosion occurred from 1979 to 1986,reaching a retreat distance of 95.7 m and an average erosion rate of 8.32 m/a.(2)The barrier area gradually decreased,and the tidal channel widened during the study period.The rate of barrier area reduction from 1979 to 1986 reached 0.0142 km2/a;according to statistics,barrier area in 2021 has shrunk by 43%compared to that in 1975.The average tidal channel widening rate from 2001 to 2014 was 14.01 m/a,and the tidal channel width exceeded 300 m in 2015.(3)Before 1980,the general trend of the offshore slope silted and became shallower,and isobaths migrated seaward.Later,as the erosion area increased,isobaths migrated landward.The evolution of the Yuehu barrier-lagoon coastal landform in Rongcheng Bay is mainly affected by human activities and coastal sediment transport.

关 键 词：荣成湾 月湖 沙坝 潮汐通道 水下岸坡 

分 类 号：P737.14[天文地球—海洋地质]