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318小时的逐时高度观测值，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—5天的周期为主，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—4小时的周期性变化，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.(4) 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.

国家自然科学基金项目（40576041）

[1] FORBESA D L, PARKESB G S, MANSONA G K, et al. Storms and shoreline retreat in the southern Gulf of St. Lawrence[J]. Marine Geology,2004,210:169—204
[2] DAIL H J, MERRIFIELD M A, BEVIS M. Steep beach morphology changes due to energetic wave forcing[J]. Marine Geology,2000,162:443—458.
[3]. HILL H W, KELLEYB J T, BELKNAPB D F, et al. The effects of storms and storm-generated currents on sand beaches in Southern Maine, USA[J]. Marine Geology,2004, 210:149—168.
[4] STONE G W, LIU BAOZHU, PEPPER D A, et al. The importance of extratropical and tropical cyclones on the short-term evolution of barrier islands along the northern Gulf of Mexico, USA[J]. Marine Geology, 2004, 210: 63—78.
[5] 蔡锋,苏贤泽,杨顺良,等. 厦门岛海滩剖面对9914 号台风大浪波动力的快速响应[J]. 海洋工程,2002,20(2):85—90.
[6] 王文海,吴桑云,陈雪英. 山东省9216号强热带气旋风暴期间的海岸侵蚀灾害[J].海洋地质与第四纪地质,1994,14(4):71—78.
[7] 陈子燊.弧形海岸海滩地貌对台风大浪的响应特征[J].科学通报,1995,40(23):2168—2170.
[8] 陈子燊,李志强,王扬圣.台风作用下海滩剖面地形动力与侵蚀机制分析[C]//第十三届中国海洋工程学术讨论会会议论文集.北京：海洋出版社，2007:331—336.
[9] LI Y, LARK R M, REEVE D E. Multi-scale variability of beach profiles at Duck: A wavelet analysis[J]. Coastal Engineering, 2005,52:1133—1115.
[10] REEVE D E, LI Y, LARK R M, et al. An investigation of the multi-scale temporal variability of beach profiles at Duck using wavelet packet transforms[J]. Coastal Engineering, 2007,54:401—415.
[11] WRIGHT L D, SHORT A D. Morphodynamics of beach and surf zones in Australia[M]// CRC Handbook of Coastal Processes and Erosion. Florida: CRC Press,1983:35—64.
[12] 陈子燊,李志龙,陈建耀,等.常波况下前滨剖面地形动力过程分析[J]. 海洋通报,2007,26(4):12—18.
[13] 彭玉华. 小波变换与工程应用〔M〕. 北京:科学出版社,1999:137.
[14] 张善文，雷英杰，冯有前. MATLAB在时间序列的应用〔M〕. 西安：西安电子科技大学出版社，2007：204—207.
[15] 李订芳, 胡文超, 章文. 基于小波包分析中的时间序列变点探测算法[J]. 控制与决策, 2005,20(5):521—524.