南海宣德海域表层沉积物粒度特征及其输运趋势

对宣德海域151个表层沉积物样品进行了粒度组分、粒径参数分析，结果表明岛礁区分布有8种沉积物类型，粒度组成以砂和砾为主，粉砂和黏土相对较少。通过因子分析和聚类分析，研究区可分为4类沉积区，Ⅰ区位于研究区中心地带，Ⅱ区位于岛礁附近海域，Ⅲ区主要位于环礁中心海域，Ⅳ区主要位于宣德环礁的礁盘外沿海域。粒径趋势分析显示，沉积物输运格局与研究区水动力条件吻合，并在七连屿海域形成汇聚区。

SEDIMENT GRAIN SIZE DISTRIBUTION PATTERN AND TRANSPORTATION TREND IN THE XUANDE WATER,SOUTH CHINA SEA

Grain size analysis and parameter calculation have been carried out for 151 surface sediments collected from the Xuande Waters in the South China Sea. Results show that the surface sediments of the area are made of 8 types of sediments dominated by sand and gravel. Silt and clay contents are relatively small. Factor and Cluster analysis of grain size parameters is used to discriminate different depositional environments. The study area can be further divided into four subareas, The subareaⅠis mainly located in the middle of study area, the subarea Ⅱnear the reefs, the subarea Ⅲ located in the inner Xuande Atoll, and the subarea Ⅳ located in lateral edges of the reef atoll. Grain size trend analysis suggests that the sediment transport pattern is consistent with the hydrodynamic conditions of the study area, and a sediment depositional area is formed in the water next to the Tri Ton island.