A Study On Sedimentary And Moving Characteristics Of Sandy Dunes In The Eastern Coast, Changle, Fujian

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.