东山乌礁湾海滩表层沉积物粒度时空变化分析  

Spatial and temporal characteristics of surface sediment grain size in Wujiao Bay, Dongshan Island

作　　者：周在明[1] 杨燕明[1] 陈本清[1] 

机构地区：[1]国家海洋局第三海洋研究所,福建厦门361005

出　　处：《海洋科学》2016年第10期82-90,共9页Marine Sciences

基　　金：海洋公益性行业科研专项经费资助(201005010)~~

摘　　要：为了进一步了解海岛岬湾海岸表层沉积物粒度的时空分布特征和形成机制,作者以福建东山岛乌礁湾为典型研究区,通过秋、春、夏3个不同季节海滩表层沉积物的采集和点位测量,综合应用激光法和筛析法进行粒度测定。结果表明,东山乌礁湾海滩表层沉积物以0.16～0.50 mm之间的中、细砂为主,并含有少量的粗砂和细砾,这与区域砂质沉积背景有关;湾内从南到北剖面沉积物粒径由粗砂到细砂逐渐变细,主要受剖面地形、局地物源、季节性风浪作用和近岸往复水动力的影响。时间变化上,各取样站位表现出沉积物粒径粗、细不同程度的多种变化趋势,以秋季为参考,整体上表现为由南到北粒级的变小、增大和稳定,这与东北、南南西季风影响下的浪、潮作用以及沿岸流系格局变化下的水动力环境有关。In order to further understand the spatial and temporal grain size distribution of surface sediments in a cape-bay coastal environment, Wujiao Bay, Dongshan Island, Fujian province was studied as a representative area. Surface sediment samples were collected during October 2013（autumn）, February 2014（spring）, and July 2014（summer）. Sediment grain size was analyzed using a Mastersizer 2000 laser particle size analyzer and a sieve method. Sampling position and profile altitude were measured using a GPS. Results showed that sandy sediments（0.16–0.500 mm） were the dominant particles. Moreover, a small quantity of coarse sand or fine gravel existed, which was in agreement with the sandy sedimentary environment. From south to north, the sediments gradually changed from coarse to fine sand, and the grain size distribution tended to be smaller. This may be caused by the cape-bay coastal geomorphology, dynamic effects of wind and waves, and local sediment provenance. Seasonal variation of sediment grain sizes at each sampling point changed complicatedly with different degree. In general, grain sizes changed from smaller to larger and were more stable from south to north along the Wujiao Bay coastline, compared with sediments from autumn 2013. This may be due to different marine hydrodynamics during different seasons or due to the effects of the NE and SSW monsoon, wave, tide, and current systems.

关 键 词：乌礁湾 表层沉积物 时空变化 粒度参数 频率曲线 

分 类 号：P736.2[天文地球—海洋地质]