琼州海峡南岸海岸动力地貌研究

COASTAL DYNAMIC GEOMORPHOLOGICAL RESEARCHES ON SOUTH COAST OF QIONGZHOU STRAIT

岬湾相间的琼州海峡南岸在海岸动力条件作用下，岸滩发生侵蚀或堆积，特别是南岸中部的南渡江三角洲沿岸岸滩演变剧烈。该文从海岸动力地貌的角度，对琼州海峡南岸的海岸动力特征、泥沙运动以及岸滩演变进行分析。根据海峡南部三维潮流场数值模拟结果，结合经验公式初步分析潮流引起的泥沙运移速率和方向，得到岸外水域总的泥沙运移趋势为从西向东。根据波浪动力计算分析沿岸泥沙运移，探讨沙质岸滩的动态与地貌演变之间的关系，得出海峡南岸海岸地貌演变与盛行的NE和NNE向风浪有密切关系，岸滩的演变过程主要受制于这两个方向的风浪及其引起的泥沙沿岸运移。

The south coast of the Qiongzhou Strait, especially its middle part,alternating between promontories and bays, is subjected to erosion and deposit underthe actions of coastal dynamics such as waves and tidal currents. The coastal dynamicfeatures, sediment transport and beach evolution along the south strait coast areanalyzed in the view of coastal dynamic geomorphology. By the 3-D tidal currentnumerical model, the sediment transport caused by tidal current is predicted tO mainlyoccur in the offshore, which has no obvious effect on nearshore landform, and thesediment transport trend in the area is from west to east. On the base of wavedynamic analysis, longshore sediment transport is computed so as to further understandthe relationship between sand beach dynamics and geomorphic evolution. The resultsshow that the prevailing NNE wind wave is the main cause of nearshore sedimentmovement and geomorphic evolution. The sand bare and spits also indicate thelongshore sediment transport from east to west.