【作者】 刘建辉；

【导师】 郭占荣；

【作者基本信息】 厦门大学 ， 海洋地质， 2007， 硕士

【摘要】 长乐东部沿岸的海岸风沙规模之大、海岸风沙地貌类型之多、海岸沙丘发育之典型,在我国东南沿海很有代表性。本文作者在了解和掌握了国内外海岸风沙研究现状的基础上,针对长乐东部海岸风沙研究的某些薄弱环节,重点对风沙沉积构造、风沙流结构、风蚀坑进行了详细观测和研究,并对该海岸带的风沙灾害提出合理的防治措施。通过对海岸沙丘的天然剖面和人工开挖剖面的观测和研究,研究区海岸沙丘沉积构造类型可以归结为水平层理、板状交错层理、发散状层理、楔状交错层理、同生变形构造等,文中对每种构造的特征进行了详细描述。通过对不同地貌单元风沙流结构的对比观测和研究,在海滩后缘、活化沙丘顶部和固定沙丘顶部,风沙流中输沙量随高度的变化存在差异,风沙流中沙粒的粒径在垂直分布上的变化规律也不相同。文中对造成风沙流结构差异的主要影响因素进行了分析。通过对槽形沙丘风蚀坑的观测和研究,分析和讨论了风蚀坑的形态特征、风蚀坑内的风速与风向变化、风蚀坑的风沙搬运与沉积过程,以及风蚀坑的成因和风蚀坑的演化阶段。论文最后在调查风沙灾害现状和防治现状的基础上,提出了海岸风沙防治与风沙资源开发并重的建议和具体措施。更多还原

【Abstract】 This research covers the geomorphology and geodynamics of the coastal dunes at east coast of Changle, Fujian, China. As far as the scales and relief types are concerned, they can be considered as one of the typical examples for the China’s southeastern dune formations.One of the aims of this research is to fill the missing points of the previous studies. In addition, this research particularly focuses on these problems, such as, internal sedimentary structures, and configuration of drifting sand flux, and general patterns and mechanism of wind induced sand movement.Furthermore, the sedimentary structures are classified into five types in details which also include internal deformational structures of the dunes on the basis of the observations and outcomes of this research. These are: horizontal bedding, tabular cross-bedding,“scalloped”cross bedding, wedged cross-bedding and contemporaneous deformation structure.Furthermore, drifting sand flux patterns in the different relief types are identified under the scope of the studies in three different sites along the beach profile. For this purpose a sediment trap is used. According to the outcomes of the sediment trap experiment, an inverse relation between the sand transport flux and the increasing height level on the sediment trap is determined. In these three sites vertical grain size distribution show normal grading sequence of stratification (e.g., coarser at the bottom, finer at the top), however, the sequence of the distribution does not show uniformity among the same trap height levels on the each selected sites. In this connection, it is also concluded that, sediment flux mainly depends on the grain size, and the distance from the beach face.The geomorphological features and patterns, the variations of wind speed and direction, Aeolian sand transport mechanism and processes, dune formation stages are also investigated. Under the light of existed knowledge, assessments of dune prevention and mitigation measures are also considered.更多还原