ON THE EROSION MECHANISM AND RESTORATION STRATEGIES OF BANYUE BAY BEACH IN QUANZHOU CITY,FUJIAN,SOUTH CHINA
This paper detailed analysis was conducted on the erosion status of Banyue Bay beach by comparing changes in the historical shoreline,cross-section,underwater topography,and longshore sediment transport.The dynamic mechanism of beach erosion in Banyue Bay was explored,and targeted beach restoration approaches were proposed.Results show that since the construction of the fishing port breakwater,a net eastward longshore sediment transport occurred in Banyue Bay.The western side of the beach has experienced continuous erosion,while the eastern side has undergone continuous siltation.In 2004～2014,the maximum shoreline retreat rate was approximately-8.1 m/a,and the maximum accretion rate was 10.1 m/a.In 2015～2017,the annual maximum net erosion volume per unit width was 10.99 m3/m,and in 2017～2021,the annual maximum net accretion volume per unit width was 26.05 m3/m.The changes in shoreline,cross-section,and underwater topography have been gradually weakened,indicating that longshore sediment transport and shoreline adjustment in Banyue Bay tended to be stabilized.Relationship between beach erosion and the construction of the breakwater in Banyue Bay was closely related.After the breakwater construction,the incident waves from the southeast direction were obstructed by the breakwater,resulting in reduced wave height and weakened dynamics in the eastern section of Banyue Bay.The previously balanced sediment transport situation was disrupted,leading to net eastward longshore sediment transport.To understand the coastal erosion mechanism,we proposed a restoration strategy of"beach nourishment on the shoulder,permeable breakwater in the central area,and pebble cape in the western part",by which longshore sediment transport has been reduced effectively and the coastal erosion due to breakwater construction alleviated.This study provided valuable references for the restoration of similar coastal beaches.
万方数据
维普
