摘要
潮间带沙坝是指在砂质潮间带发育的脊槽组成的海岸沉积地貌形态,可以分为低振幅沙脊和潮间带沙波两种类型,在全球广泛分布,具有重要的海岸防护和生态价值。基于2017~2023年的Google Earth和Sentinel-2的遥感影像,结合实地地形观测,对中国海岸上潮间带沙坝的空间分布及其地形特征,进行了全面的研究,并分析了其发育的沉积物和水动力条件。中国海岸有47处潮间带沙坝,确定其中24处为低振幅沙脊,23处为潮间带沙波,主要分布在中小河口附近等砂质沉积物丰富而泥质沉积物又无法存留的地区。在跨岸方向上,低振幅沙脊通常由2~6道沙坝组成,沙坝多为新月型,平均沙坝间距主要介于65~142 m,脊线不连续且位置变化明显。而潮间带沙波则发育有6~20道沙坝,平均沙坝间距介于67~101.5 m,空间上呈现出完整、连续、分离且平行的特征,时间上位置稳定。水动力分析结果显示,低振幅沙脊主要发育在中低波能(有效波高介于0.45~1.82 m)和平均大潮潮差介于1.02~6.45 m的条件下。潮间带沙波在低波能(有效波高介于0.36~0.72 m)和平均大潮潮差介于1.01~4.34 m的环境下形成。中国海岸的潮间带沙坝发育广泛、种类多样、空间跨度大,是重要的海岸沉积地貌单元,有必要对其开展系统性的全面研究,从而为海岸管理和保护提供科学依据。
Intertidal bars are coastal landforms formed by ridge and troughs developed in sandy intertidal zones,and can be classified into two types:low-amplitude ridges and intertidal sand waves.They are widely distributed globally and hold significant coastal protection and ecological value.Based on remote sensing images from Google Earth and Sentinel-2 in 2017~2023,combined with field topographic observations,the spatial distribution and morphological characteristics of intertidal bars along the coast of China,as well as the sediment and hydrodynamic conditions contributing to their formation were analyzed.There are 47 intertidal bars along the coast of China,of which 24 were identified as low amplitude ridges and 23 as intertidal sand waves,mainly distribute near river mouths where sandy sediments are abundant and muddy sediments cannot be retained.In the cross-shore direction,low-amplitude ridges consist of 2~6 bars in interval of 65~142 m,showing discontinuity.The bars are mostly crescent-shaped,with noticeable temporal variations in ridge positions.Intertidal sand waves develop 6~20 bars with spacing between 67~101.5 m,exhibiting complete,continuous,separate,and parallel characteristics without significant temporal position changes.The results of the hydrodynamic analysis showed that low-amplitude ridges primarily develop under low to medium wave energy conditions[significant wave height(Hs)=0.45~1.82 m]and mean tidal range(MSR)=1.02~6.45 m.Intertidal sand waves form under low wave energy(Hs=0.36~0.72 m)and MSR=1.01~4.34 m environments.The intertidal bars along the coast of China are widely developed,diverse in type,and have a large spatial span,and are important coastal sedimentary geomorphic units.It is necessary to carry out a systematic and comprehensive study in the regard,to provide a scientific basis for the management and protection of the coast.
作者
万洁颖
王韫玮
郭一栋
王玺诏
于谦
WAN Jie-Ying;WANG Yun-Wei;GUO Yi-Dong;WANG Xi-Zhao;YU Qian(Key Laboratory of Coast and Island Development of the Ministry of Education,School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China;College of Marine Science and Engineering,Nanjing Normal University,Nanjing 210023,China)
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2024年第6期1406-1418,共13页
Oceanologia Et Limnologia Sinica
基金
2023江苏省自然资源发展专项资金(海洋科技创新)项目,JSZRHYKJ202303号
国家自然科学基金项目,42076172号。
关键词
潮间带沙坝
地貌特征
沉积动力环境
中国海岸
intertidal bars
geomorphological features
sedimentary dynamic environment
China coast
