杭州湾北岸潮滩沉积物粒度的时间变化及其沉积动力学意义  

Temporal Changes in Tidal Flat Sediment Grain Size Along the North Bank of the Hangzhou Bay and Their Implication of Sedimentation Dynamics

作　　者：陈沈良[1] 杨世伦[1] 吴瑞明[1] 

机构地区：[1]华东师范大学河口海岸国家重点实验室,上海200062

出　　处：《海洋科学进展》2004年第3期299-305,共7页Advances in Marine Science

基　　金：国家自然科学基金重点项目--强潮海湾粉砂物质与海岸系统行为(40231010);国家自然科学基金项目--高强度开发背景下长江三角洲南翼岸滩过程和响应(40276027)

摘　　要：2002年5月-2003年4月对杭州湾北岸中潮滩一个固定观测点表层沉积物进行逐日取样,采用库尔特LS100Q型激光粒度仪进行粒度分析,探讨潮滩沉积物粒度随时间的演变。结果表明,潮滩粒度特征在时间上有明显的变化,1-6月潮滩堆积期间沉积物粒度较细,7-12月潮滩侵蚀期间沉积物较粗,其中1月和7月为潮滩冲淤转换期间沉积物粒度显示双峰分布;沉积物年平均粒度亦显示双峰分布,细颗粒部分主要是由于悬沙落淤形成,而粗颗粒部分主要是由于潮滩下部粉、细砂物质向上推移形成。通过潮滩沉积动力学的探讨阐明了潮滩沉积物粒度演变的原因和特点。The daily surface sediment samples at a mesotidal flat sampling site along the north bank of the Hangzhou Bay were collectad from May 2002 to April 2003, and the size analysis of sediment samples was made by using Model LS100Q Coulter laser particle size analyzer to study the temporal changes in tidal flat sediment grain size. It is shown from the study results that the tidal flat sediment grain sizes showed significant temproal changes. The sediment sizes were finer during the tidal flat accretion period from January to June, and were coarser during the tidal flat erosion period from July to December, among them, the sediment sizes showed bimodal frequency distributions during the erosion and deposition conversion periods in January and July, respectively.The annual mean sediment sizes also showed bimodal frequency distributions. It is shown from the analysis results that the fine-grained components resulted mainly from the deposition of suspended sediments in water column, and the coarse-grained components resulted mainly from the upward moving of silt and fine sand on the lower tidal flat. The sedimentation dynamics is used to discuss the causes and characteristics of tidal flat sediment size evolution.

关 键 词：潮滩 沉积物粒度 库尔特激光粒度仪 沉积动力学 杭州湾 

分 类 号：P736.21[天文地球—海洋地质]