台风季节典型岬湾沙滩的变化分析

Processes of typical embayed beaches during typhoon season

采用建立的天文潮-风暴潮-台风浪模型,计算2019年台风季浙江沿海岬湾4处沙滩前沿的波浪和潮位过程。根据现场实测资料,台风季早期,滩面潮间带及潮上带主要为冲刷,强波浪对天然沙滩的冲刷影响不大,幅度在0.2 m以内。沙滩潮间带泥沙粗化,滩面的倒坡比与波高综合参数H/DT~2基本呈线性关系。台风季中晚期,东沙和皇城沙滩总体上继续冲刷,洞下和渔寮沙滩回淤,两处沙滩存在季节内的恢复和泥滩向沙滩供沙的现象。台风季前后对比,天然沙体积变化1.5%,修复沙滩减少5.0%,部分沙滩潮下带出现泥化。研究成果可为沙滩修复和泥滩上沙滩的修建设计提供重要的参考。

Based on astronomical tide-storm surge-typhoon wave model,wave and tidal-level processes were calculated in the nearshore areas of four beaches during the 2019 typhoon season.According field measurements,in the early stage of typhoon season,intertidal zone and supratidal zone of beach surface mainly showed scour,and strong waves make small impact on scour of natural beach with a range of scour about 0.2 m,the sediment in intertidal zone of beach was coarsened,and the inverse ratio of beach slope is linear with the comprehensive parameter of wave height(H/DT~2).During the middle and late stages of the typhoon season,Dongsha and Huangcheng Beaches were scoured,Dongxiao Beach and Yuliao Beach were slightly deposed,where there was recovery and the sand supplying the beach from the tidal flats.Compared beaches at the beginning with at end of the typhoon season,the upper part of the beach was scoured,the lower part is deposed,the natural beach is slightly scoured or deposed,the volume change of beach is 1.5%,and the volume of beach which has been nourished is reduced by 5.0%,and the subtidal zone appeared muddy.