台风影响下海滩前滨剖面时间变化差异性分析  

Analysis on temporal change of foreshore profile under tropical storms

作　　者：陈子燊[1] 王扬圣[1] 黄德全[1] 刘萌伟[1] 

机构地区：[1]中山大学水资源与环境系,广东广州510275

出　　处：《热带海洋学报》2009年第6期1-6,共6页Journal of Tropical Oceanography

基　　金：国家自然科学基金项目(40576041)

摘　　要：利用2006年8月2日至16日0606号台风"派比安"和0609号强热带风暴"宝霞"影响期间于粤东后江湾中部海滩前滨设置的地形剖面6个固定观测桩点上连续318h的逐时高度观测值,基于一维最优小波包变换方法,分析了极端波况影响下前滨剖面不同高度固定点的时间变化特征,主要结果为:(1)位于剖面冲流作用上部的桩点1、2时间变化过程以2—5d的周期为主,反映了台风作用前后剖面的波动过程;(2)位于剖面中下部的4个桩点高度显示了2—4h的周期性变化,进一步显示出台风影响期间短时高能侵蚀作用导致的剖面地形迅速调整,以及台风后潮汐周日变动对滩面地形的影响;(3)各桩点高频尺度的突变时间点反映出了台风暴潮增水作用和碎波带沙坝进退引起剖面的蚀积变化;(4)各桩点地形高度的低频变化显示出台风后海滩剖面朝向堆积和恢复的趋势。Using the hourly data at six fixed sites （Pegs 1-6） for foreshore profile during Typhoon Prapiroon （Typhoon No. 0606） and severe tropical storm Bopha （No. 0609） from August 2-16, 2006, the authors analyze the characteristics of temporal changes in beach elevation based on one-dimensional optimal wavelet packet transform. The results are as follows. （1） The temporal change is dominated by 2-5 day period for Pegs 1 and 2 at the upside of the profile, reflecting the recovery process of the profile before and after the storms. （2） The heights of the four pegs at the mid-lower portion of the profile, with a periodical variation of 2-4 hours, showed a short-term erosion caused by storms, which resulted in a quick adjustment of the profile topography and the influence of diurnal tidal fluctuation on the beach front heights. （3） The temporal points with abrupt change in high-frequency scale of the pegs reflected the mutability of the profile topography under the influences of storm surge set-up and advance-and-retreat of sand bars in the surf zone. （d） The topography changes in low-frequency scale at the pegs indicated a trend towards stable accumulation and recovery of the profile topography after the storms.

关 键 词：台风 前滨剖面 时间变化 最优小波包变换 

分 类 号：P737[天文地球—海洋地质]