福建湄州岛西南部海滩重塑后剖面的季节变化特征

湄洲岛西南部海滩因1996年建造对台客运码头，引起了海滩剖面的变化，码头前沿淤积而报废。经过5年后，海滩剖面仍未能完全趋于平衡。为了了解码头建设对重塑后海滩的季节变化影响，在2001年3月、7月、10月和12月对码头所在海滩剖面地形进行季节重复测量，并对剖面变化进行比较分析。结果表明，重塑后海滩剖面的季节变化存在区段差异性，码头工程区海滩剖面仍表现为不断淤积，表明5年来工程建设造成海滩重塑后的变化过程还在继续；过渡区海滩剖面较工程区淤积程度减弱，部分剖面表现为侵蚀趋势，但总体逐渐向正常海滩剖面的季节变化方向发展；正常区海滩剖面的季节变化具有一定的规律性，表现为夏季上部侵蚀（后滨和高潮带）下部淤积（低潮带和浅水区），冬季上部淤积下部侵蚀，春、秋两季为中间过渡剖面形态。

THE SEASONAL PROFILE CHANGE CHARACTERISTICS DUE TO BEACH RESHAPING SOUTHWEST OF MEIZHOU ISLAND IN FUJIAN

The beach profile change southwest of Meizhou island occurred due to the construction of a passenger pier open to Taiwan in 1996,which caused a great deal of silting around the pier apron and resulted in the discard of the pier.Five years later,the beach profile still could not reach a balance state.In order to find out the influence of pier construction on the seasonal change during beach reshaping,we measured the landform related to the beach profiles in March,July,October and December 2001,then compared and analysed the changes in the profiles.The results showed that the seasonal changes in the profiles varied in different sections:1) the beach profile around the pier project section still shows continuous deposit,indicating that the project construction still affects the beach change process of reshaping over the past 5 years; 2) deposit in the transitional beach section is weaking,part of the profiles show erosion,and the seasonal changes there are close to those of natural beach profiles,3) the seasonal changes in the natural section show regularity that the upper part beach profiles(backshore and high tide belt) are eroded and the nether part beach profiles(low tide belt and shallow section) are deposited in Summer,and the opposite occurs in Winter,and the beach profile form is transitional in Spring and Autumn.