华南海岸岬间海滩地形动力状态类型研究

Morphodynamic characteristics and classification of headland beaches in South China Coast

海滩地形动力状态分类对于理解近岸带动形动力过程、海滩浴场风险评估等方面有重要的意义。收集了华南51个岬间海滩波高、波周期、潮差和泥沙粒径等地形动力要素特征值,利用分层聚类分析方法,同时结合海滩相对潮差分类模型,对华南岬间海滩的类型进行了探讨,结果表明:(1)华南岬间海滩可以聚类成7个类型。通过与相关的现场观测比较,各类型在地形组合上具有各自的显著特征;(2)聚类分析结果能很好的区分中到大潮差海岸与小潮差海滩之间的差异,与相对潮差模型结果一致。对于小潮差海滩,聚类结果与相对潮差模型有一定的差异,表明华南小潮差海滩的分类还需要进一步深入研究。

Beach morphology varies with changing hydrodynamic force（ waves and tides）. The beach state classification models based on the morphodynamics are useful in providing a conceptual framework within which beach and nearshore zone environments can be studied and understood, and providing the important information for beach management to assess the beach bath risk. In this sense, the present study classifies 51 South China headland beaches with hierarchical cluster analysis based on the wave heights, periods, tidal ranges and sediment sizes, and makes a comparison with the relative tide range model proposed by Masselink and Short（1993）. Some conclusions were reached in the following：（1） From the cluster analysis, 7 beach groups were defined at the 3.5 similarity distance and the groups has different beach morphological combination.（ 2） Hierarchical cluster analysis and morphodynamic indicesΩ-RTR were found to be effective in discriminating beaches in meso- and macrotidal environments. In the microtidal coast, the cluster analysis groups and the beach state classifications have some difference. It means that there needs extensive work before revealing the microtidal beach classification in South China.