常浪条件下海滩滩角地形变化研究  

A Study on the Morphological Evolution of Beach Cusps under the Normal Wave Conditions

作　　者：李志强[1] 陈子燊[2] 

机构地区：[1]广东海洋大学海洋工程系,广东湛江524088 [2]中山大学水资源与环境系,广东广州510275

出　　处：《海洋通报》2008年第1期60-67,共8页Marine Science Bulletin

基　　金：国家自然科学基金资助项目(40576041);广东海洋大学引进人才科研启动资金项目(E06049)

摘　　要：通过对滩角地形的详细观测,研究了滩角在常浪条件下的调整和变动过程。通过对地形动力要素和滩角地形变化过程的详细分析,认为Masselink等提出的碎波相似参数ξ和用ε(S/λ)2建立的滩角地形模式,能较好地反映常浪条件下滩角的调整变动过程。通过对比,初步认为二者之间有较强的相关性。滩角凸部和凹部的蚀积速率差异,可以引起滩角的消亡或发育。利用EOF分析方法能把滩角的主要变化过程分离出来:滩角在常浪条件下的变动主要含有沙坝运动过程、冲流变化过程和波浪变化过程等3个过程,占数据方差的99%以上;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。Beach cusps, which are formed by the wave, are extremely complex and have rhythmic topography on the beach. Beach cusps are related to the beach states either. Based on the detailed observations of morphodynamics and topography of the beach cusps, a study on the beach cusp morphological evolution under the normal wave conditions is carded out. Results show that the beach cusp morphodynamic models established by Masselink et al. （1997） are effective to descript the adjusting process of beach cusp under normal wave conditions, and ξ （ surf similarity parameter ） and ε （S / λ）^2 are two parameters in models. The two parameters are rather correlative in this case. The differences of erosion or deposit rate between the horn and embayment may induce the beach cusp growth or fade away. The mainly adjusting processes of the beach cusp under the normal wave conditions are distinguished by empirical orthogonal function （EOF）. Results show that beach cusp variations are comprised of three dominating processes： sub-tidal sand bar movement, swash variations and wave variations. The vertex of the beach cusp is the turning point of the horn profile variations while the profile of the embayment changes linearly.

关 键 词：滩角 地形动力 经验正交函数(EOF) 海滩过程 碎波相似参数 

分 类 号：P737.1[天文地球—海洋地质] P736.21[天文地球—海洋科学]