【摘要】：研究臺風影響下的海灘沉積過程不僅可加深極端海況下的海灘沖淤變化理解,而且有利于海灘資源的保護與海岸工程保護。以強潮海灘——北海銀灘為例,通過采集北部灣海區(qū)1409號威馬遜超強臺風作用前后的沉積物、剖面高程及水文資料,探討強潮海灘的動力沉積過程。結(jié)果表明:1)臺風作用前后的海灘沙丘-灘肩-沙壩體系的地貌狀態(tài)基本不變,其中沉積物組分均為砂,細砂、極細砂和中砂三組分平均含量占所有組分的95%以上;與臺風作用前比較,臺風后的地貌在維持先前形態(tài)的條件下,發(fā)生局部侵蝕和后退,沉積物相對變粗且細砂含量增加了10%。2)臺風作用后后濱沙丘侵蝕,且沉積物滾動組分增加;沖流帶和灘肩前緣沉積物的搬運由雙跳躍轉(zhuǎn)為單一的跳躍形式。3)臺風作用前后的海灘沉積物主要變化過程可由兩個模態(tài)表征,其中主要模式反映了臺風作用前后的海灘以細砂為主的動力沉積變化特征,該模式受控于區(qū)域波浪和潮汐的長期耦合作用,并以波浪為主導(dǎo)因素。臺風作用前的次要模式反映潮汐作用控制下的海灘沉積橫向振蕩特征;臺風作用后的次要模式表征了臺風影響下的海灘橫向沉積物偏粗、沖流帶-低潮帶振蕩及其沉積分異過程。
[Abstract]:The study of beach sedimentation process under the influence of typhoon can not only deepen the understanding of beach scour and siltation under extreme sea conditions, but also benefit the protection of beach resources and coastal engineering. Taking the strong tidal beach-Beihai Silver Beach as an example, the dynamic deposition process of the strong tidal beach was discussed by collecting the sediment, profile elevation and hydrological data before and after the action of the 1409 Vermaeson Super Typhoon in the Beibu Gulf Sea area. The results show that the geomorphologic state of beach dune-beach shoulder-sand dam system before and after typhoon is basically unchanged, and the average contents of sediment components are sand, fine sand, very fine sand and medium sand, which account for more than 95% of all the components. Compared with that before typhoon, local erosion and receding occurred in the geomorphology after typhoon, and the sediment became thicker and the fine sand content increased by 10.2) after typhoon, sand dune erosion and sediment rolling component increased. The main changes of beach sediments before and after typhoon action can be characterized by two modes. The main model reflects the dynamic sedimentary characteristics of the beaches before and after typhoon action, which is controlled by the long-term coupling of regional waves and tides, and the wave is the dominant factor. The secondary model before typhoon action reflects the characteristics of lateral oscillation of beach sediment under the control of tidal action, and the secondary model after typhoon action indicates that the beach lateral sediment under typhoon action is coarse. The oscillations and sedimentary differentiation processes of the scouring zone and the low tide zone.
【作者單位】： 廣西北部灣海岸科學(xué)與工程實驗室;華東師范大學(xué)河口海岸學(xué)國家重點實驗室;
【基金】：國家自然科學(xué)基金(41376097,41666003) 廣西自然科學(xué)基金(2015GXNSFBA139207) 2015廣西高等學(xué)校科學(xué)研究人文社科重點項目(KY2015ZD133)
【分類號】：P737.1;P748
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本文編號：2181758