0709号台风影响下粤东后江湾海滩地形动力过程研究

摘要

Based on the foreshore topography,water dynamics and wind data on Houjiangwan beach in East Guang-dong,this paper used the method of canonical correlation analysis to identify different morphodynamic foreshore processes under the influence of the typhoon “Sepat”(No.0709),and revealed some primary dynamic factors con-trolling these foreshore processes and attempted to present the physical interpretations.The analytical results in-cluded that (1)the primary foreshore process consisted of the eroded subaerial zone with the destroyed berm,the slightly depositional submarine slope zone and the bar zone with sediment movement offshore,and the process was controlled by several factors such as the eastern component of the wind speed,the maximum wave heights and the surf scaling parameter;(2)the secondary terrain process was the formation of submarine bar due to the sediment being transported from the foreshore to offshore,and the process was dominated by two dynamic factors such as the maximum wave periods and the beach underground water levels;and (3)the foreshore morphology was also char-acterized by the accumulation of the upper zone and the erosion of the lower zone of the foreshore,and the process was controlled by the following factors,i.e.,the longshore currents,the beach underground water levels and the maximum wave heights.Finally,this study proposed that the morphodynamic processes of the foreshore are cou-pled by many different morphological and dynamic processes.%基于0709号台风“圣帕”影响下粤东后江湾的现场实测海滩前滨地形资料和水动力、风等资料，采用典型相关分析方法识别了台风影响下海滩前滨地形不同的变化过程，揭示了这些不同变化过程的主要控制因子，并尝试给出了物理解释。研究结果表明：（1）台风影响下海滩前滨地形的主要变化过程是水上滩肩被破坏—水下岸坡略有堆积—水下沙坝泥沙向海搬运，控制这一过程的主要动力因子是风速东向量、最大波高和碎波尺度参数；（2）海滩前滨地形的次要变化过程是海滩前滨泥沙向海搬运而形成水下沙坝，控制这一过程的主要动力因子是最大波周期和海滩地下水位；（3）海滩前滨地形也表现出前滨上部地带堆积、下部侵蚀的变化过程，控制这一过程的主要动力因子是沿岸流、海滩地下水位和最大波高。这些研究结果进一步揭示了台风影响下海滩前滨地形动力过程是由多个不同的地形－动力过程耦合作用而组成。