礁冠对珊瑚礁不规则波演变影响的数值模拟研究  

Numerical study on the effect of reef crest on the evolution of irregular waves over coral reefs

作　　者：柳叶 穆言 李绍武[1] LIU Ye;MU Yan;LI Shaowu(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《长沙理工大学学报（自然科学版）》2023年第4期20-26,共7页Journal of Changsha University of Science and Technology:Natural Science

基　　金：天津市自然科学基金资助项目(22JCQNJC00660);国家自然科学基金资助项目(52201333)。

摘　　要：【目的】研究不规则波作用下珊瑚礁礁冠对波高及增水的影响规律。【方法】采用非静压数值波浪模型模拟不同礁坪静水深、波高、谱峰周期的多组工况,对比礁冠存在与不存在时波浪空间演化的差异。【结果】礁冠存在时,礁缘附近破波区变窄,波浪破碎强度显著增强,礁坪末端波高变小,增水高度变大;礁冠对礁坪末端波高和增水的影响随礁坪静水位的升高先增强后减弱,礁坪静水位为低水位和高水位时礁冠的影响较小,为中等水位时礁冠的影响较大;礁冠存在时,礁坪末端波高和增水高度随入射波波高及谱峰周期的增加而增大。【结论】礁冠通过改变礁缘附近波浪的破碎过程影响礁坪末端的波高与增水,其影响程度与礁坪静水位密切相关。本文研究成果可为珊瑚礁海岸防灾减灾提供参考。[Purposes]An investigation of the influences of reef crest on the wave height of irregular waves and wave setup over the reef flat is reported in this pape.[Methods]A non-hydrostatic numerical wave model was used to simulate a series of test cases under different still water depths over the reef flat,wave heights,and wave periods,and to compare the difference of wave evolution process in the presence and absence of a reef crest.[Findings]Results showed that,the depth reduction under the presence of reef crest caused significant enhancement to the wave breaking tensity at the reef edge while shortening the width of the surf zone;the reef crest caused a decrease in the wave height and an increase in the wave-induced setup at the reef end;the effects of the presence of a reef crest to the wave height and wave-induced setup at the reef end first increase and reaches a maximum with increasing reef flat water depth,before begin to decrease;with the presence of reef crest,the wave height and setup at the end of the reef increased with incident wave height and spectral period[.Conclusions]The reef crest influences the wave height and setup at the end of the reef flat by altering the wave-breaking process near the reef edge,and the degree of influence is closely related to the still water depth(tide level)of the reef crest;the results of this paper can provide a reference for coral reef coastal disaster prevention and mitigation.

关 键 词：珊瑚礁 礁冠 波浪破碎 增水 防灾减灾 

分 类 号：P753[交通运输工程—港口、海岸及近海工程]