OVERVIEW OF INTERTIDAL BARS ALONG THE CHINA COAST:GEOMORPHOLOGICAL FEATURES AND FORMATION CONDITIONS
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.
万方数据
维普
