【作者】 宋晓红；

【导师】 王江涛； 石学法；

【作者基本信息】 中国海洋大学 ， 分析化学， 2006， 硕士

【摘要】 论文根据国内外对陆架边缘海域悬浮颗粒有机质的研究现状,通过目前国际上公认的对海水颗粒有机碳(POC)、氮(PN)测定的先进方法,即利用元素分析仪和MAT-251质谱仪和Finnigan Delta plus同位素比值质谱仪测量了黄东海及长江河口区悬浮颗粒有机碳、氮含量和同位素组成,以弄清1998年长江特大洪水对黄东海悬浮颗粒物质输运的影响和三峡截流对长江口区悬浮颗粒有机物质分布的影响。主要结果如下:一、洪水事件对长江颗粒有机质入海扩散的影响1998年秋季,在黄东海采集的五层悬浮体样品中,TSM浓度与POC和PN质量浓度之间存在着显著的正相关性(r=0.90～0.98)的同时,TSM浓度又与盐度之间存在显著的负相关性(r=-0.29～-0.59);而且POC与PN质量浓度之间也存在着显著的正相关性(r=0.89～0.98)。由此推断,在该航次采集的悬浮有机质中碳氮主要是由TSM浓度所控制。颗粒有机质的C/N分子比值与PN%之间存在有显著的负相关性(r=-0.44～-0.71),但是,C/N分子比值与POC%之间却无明显的相关性,说明C/N分子比值主要是由PN%的变化所决定。δ15N与表层POC%、PN%之间都存在着显著的正相关性,相关系数r分别为0.36和0.24(p<0.01),然而在更深的水层中这种关系就不复存在了,说明颗粒氮容易受到除有机质降解以外的其它因素,诸如在水柱中营养盐的利用程度、硝化作用、反硝化作用、不同来源物质的输入等的影响,而使其同位素值发生变化。由C/N分子比值的“谷形”和δ13C的“峰形”分布可以认为,在1998年夏长江特大洪水期后长江入海悬浮颗粒可以直接被输运至冲绳海槽海区,这突破了我国学者过去根据平常水文条件下所得出的长江入海悬浮颗粒物质不能直接输运到冲绳海槽的认识。二、三峡截流后长江口悬浮体及颗粒有机碳、氮的分布和来源2004年秋末冬初,在具有高悬浮泥沙浓度的长江口区,POC、PN质量浓度和TSM含量呈现正相关关系,相关系数分别为R=0.708 6和R=0.648 3,表明长江口TSM和POM的物源一致性;而且悬浮体有机C/N比值大多数在12以上,显示了该区域TSM及其POM的陆源性质。对照了三峡截流前后长江口区的悬浮体和颗粒有机质的质量浓度分布数据,说明迄今为止三峡截流尚未对长江口区悬浮颗粒分布特征造成明显的影响。更多还原

【Abstract】 Water column concentrations of total suspended matter(TSM),particulate organic carbon(POC),particulate nitrogen(PN)and their stable isotopic compositions(δ13C andδ15N)are measured at two to five different depths in the Yellow Sea and East China Seas and Yangtze Estuary to clarify the effect of the Yangtze River close off at the Three Gorges project on the distribution of suspended matter in the estuary and the effect of’98 Yangtze great flood on the transport of suspended matter in the Yellow Sea and East China Sea. The results are followed:1. The effect’98 Yangtze great flood on the transport of suspended matter in the Yellow Sea and East China SeaSuspended matters are collected to analyze the distributions of TSM, POC, PN and S throughout the Yellow Sea and East China Sea in the autumn of 1998. There are marked positive correlations (r=0.89～0.98) among TSM, POC and PN, but negative relationships (r=-0.29～-0.59) between TSM and salinity. These results conclude that the POC and PN were controlled primarily by the concentrations of TSM.The C/N ratios of particulate organic matter have a negative linear correlation with PN % (r=-0.44～-0.71), but no correlation with POC %, which suggests C/N ratios are mainly controlled by PN %.There are distinct positive correlations betweenδ15N and POC % or PN % in surface water( r=0.36 and 0.24,p<0.01,respectively), however, the correlation don’t exist in more deeper depths. It indicates thatδ15N could be changed by a lot of factors such as nutrient utility, nitrification, denitrification, and different material sources and so on, except decomposition of organic matter.The distributions of C/N ratio andδ13C values of the particulate organic matter suggest that suspended matters from Yangtze River could be transported directly into the Okinawa Trough under the condition of’98 Yangtze great flood, which break through the foregone knowledge obtained under the normal hydrological condition.2. The distributions and source of POM in the water column throughout the Yangtze River Estuary after the Three Gorges There are positive correlations between concentrations of POC and TSM (R=0.708 7) and between concentrations of PN and TSM (R=0.648 4) throughout the turbid Yangtze River Estuary during November and December 2004, it shows the POM has the same source with TSM. Furthermore, Most samples display C:N ratio >12, suggesting the both TSM and POM in this region are mainly of terrestrial origin.Comparing the data of concentrations of TSM and POC in the Yangtze River estuary before and after the Three Gorges project, it indicates that the Yangtze River close off at the Three Gorges has not influenced on the distribution feature of TSM and POC in the Yangtze River estuary.更多还原