海滩冲流带高频振动地形动力过程分析

在粤东汕尾后江湾海滩冲流带布设2条观测剖面,共计6个观测点,对滩面冲流带在约一个潮周期内的高频振动进行了观测,取得采样频率分别为1min/次和6min/次的滩面数据各1组.结合同步观测的碎波带波浪潮汐数据,分析探讨了海滩高频振动特征.分析认为在涌浪条件下,滩面高频振动的日内变化主要受到潮位变化过程的控制,涨潮堆积,落潮侵蚀.利用交叉谱分析的结果表明滩面高程变化滞后于潮位变化.滩面下部比上部振动幅度大,变化复杂,滩角脊部比凹部活跃.波群对滩面高频振动有显著影响,特别是波高大于有效波高的波群.滩面高频振动没有表现出明显的泥沙逐渐向陆地堆积过程,有一定的振动周期.

Analysis on the morphodynamic processes of high frequency oscillation in the swash zone

Two profiles,6 stakes in total,were arranged for measuring in the swash zone of Houjiang Bay in Shanwei,Eastern Guangdong Province.Two series of beachface oscillation data were measured at interval of 1 minute and 6 minutes in around a tidal cycle.And the waves and tide levels data were collected synchronously.The analysis indicates the daily beachface oscillation tendency is dominated by the tide and the oscillations have a lag behind the tidal changes.The beachface oscillations at low position of the swash zone and cusp ridges are more complex than that at the high position and cusp embayment respectively.The wave groups have distinct effects on the high frequency oscillation of the beachface,especially when the wave heights are larger then the significant wave height.No distinct evidence showed that the sand migrated landward.