中文摘要：

以观测到的一个在较长时间存在的滩角为研究对象,研究了常浪条件下滩角的变化过程。选取其代表性的凸部和凹部剖面数据,应用经验特征函数分解的方法,结合现场观测的地形动力要素和现象,得到滩角地形变化的时空特征：①滩角的凸部是滩角形态的控制因素,对外动力的响应最为敏感。凸部的顶点是凸部形态变化的一个转折点,凹部的形态变化表现出一种线性特征;②常浪条件下,近岸水下沙坝运动过程对滩角变化起主要控制作用,表现为海滩的蚀积变化;③滩面冲流变化过程和波浪变化过程是滩角地形变化的次要模式,将水下沙坝带来的泥沙在滩面上重新分布,促使滩角地形不断地调整。

英文摘要：

A beach cusp existing for a long term under normal wave conditions was measured repeatedly. The beach cusp variations are analyzed with empirical orthogonal function （EOF） using the topography data. Taking the hydrodynamic factors and beach phenomena into account, the following results are deduced： （1） The horn of the beach cusp being sensitive to the norphodynamics may control beach cusp shape. The vertex of the beach cusp is the turning point of the horn profiles variations while the profiles of the embayment changes linearly. （2） Under normal wave conditions, sub-tidal bar movement may control the beach cusp topography variations. （3） Swash and wave variations induce beach cusp subsidiary changing models and redistribute the sand brought by the sub-tidal bar movement on the beachface.