雷州半岛红树林湿地表层沉积物粒度分布特征

对采自雷州半岛8个红树林湿地典型分布区的37个表层沉积物样品进行粒度分析,结果显示:(1)研究区表层沉积物粒度组成粉砂含量最高,占52. 9%;其次为砂,占27. 8%;黏土含量最低,占19. 3%。(2)研究区表层沉积物有砂质粉砂、黏土质粉砂、砂和粉砂质砂4种类型,其中砂质粉砂和黏土质粉砂主要分布在南山、高桥和观海长廊等地,砂和粉砂质砂主要分布在特呈岛、企水等地。(3)研究区沉积物平均粒径为5. 7,沉积物颗粒整体偏细;分选系数平均值为1. 90,分选较差;偏态平均值为-0. 14,为负偏;峰态平均为1. 07,峰态等级为中等。(4)通过系统聚类分析方法将研究区沉积环境分为三种类型,不同沉积环境水动力条件和环境特征差异明显。(5)沉积物砂粒含量与有机质含量、盐度呈极显著的负相关关系,与p H值呈正相关;粉砂含量与有机质含量、盐度呈极显著正相关,与p H值呈负相关;黏土含量与有机质含量、盐度正呈相关,与p H值则呈负相关。

Grain Size Distribution Features of Surface Sediments from Mangrove Wetland of Leizhou Peninsula

Thirty-seven surface sediments were collected from eight typical mangrove wetlands in Leizhou Peninsula and their grain-size distribution characteristics were analyzed. The results yielded the following conclusions: (1)Content of silt is the highest (52.9%), followed by sand (27.8%) and then clay (19.3%). (2)Major sediment types include sandy silt, clayey silt, sand and silty sand. Sandy silt and clayey silt are mainly distributed in the Nanshan, Gaoqiao and View-sea corridor. Sand and silty sand are mainly distributed in the Techeng Island and Qishui. (3)Average particle size is 5.7 $phi$, and in general the grains are fine and soring is poor (sorting coefficient=1.90). The average skewness coefficient is -0.14, suggesting negative deviation. The average coefficient of kurtosis is 1.07, and the peak level is medium. (4)By using the cluster analysis method,it is found that sedimentary environment in the study area can be divided into three types, and different hydrodynamic conditions and sedimentary environmental characteristics are obvious. (5)Content of sand is negatively correlated with organic matter and salinity, but positively correlated with pH.The content of silt is positively correlated with organic matter and salinity, but negatively correlated with pH.Clay content is positively correlated with organic matter content and salinity, but negatively correlated with pH.