关键词: 沉积环境, 动力地貌, 港湾海岸, 海滩, 铜鼓岭

Abstract: Through the field investigations such as geological and geomorphology survey, beach and seabed bathymetry, beach profile measurements, grain-size analyses of the sediments of the beaches and seabed, this paper makes some preliminary conclusions as follows:(1) The sands of the Yueliang Bay and the Qishui Bay are coarse-middle sands and medium and mean grain-size diameters are mainly between 1-2 Ф.The grain-size results of beach and seabed sediments indicate that the wave is great in the Yueliang Bay and the Qishui Bay in the eastern Hainan Island.The reason is that the Yueliang Bay and the Qishui Bay face the sea directly and have no barriers, so the wind wave is stronger, which is influenced distinctly by winter and summer monsoon.(2) The coastal geomorphology have great influence on dynamicical condition and sementation environment.The medium grain-size of the seabed sediments is -1--3 Ф near 20-m fathom line, and -1-0 Ф between 10-20 m fathom lines, which shows that the wave function the sea bed at 20 m depth in the Yueliang Bay.However, there are coral reefs in the Qishui Bay, which can remove some energy, so the swash wave is not stronger than that in the Yueliang Bay.(3) Moreover, the different geomorphologies in the same embayment coast result indifferent dynamic conditions.Because of the coral reef damaged in the northern Qishui Bay, the coarse sizes of the sand in the sand beach are distributed in the different parts, which indicates swash wave acts frequently in the different tides, but in the southern Qishui Bay, only at the big tide time, the swash wave can act on the beach.

Key words: sedimentation environment, morphodynamics, embayment coast, beach, Tongguling