【摘要】 三峡水库建成后,库区水体流速减慢,导致大量泥沙淤积,为揭示其沉积物总有机碳(TOC)分布特征,分别在干、支流设置8个和9个监测断面获取沉积物柱状样,以2cm为间隔,在室内进行了粒度分析和总有机碳(TOC)含量测定.结果表明,干流总有机碳(TOC)含量最大值出现在磨刀溪断面,最小值出现在云阳断面,分别为1.05%、0.72%,总体上,干流总有机碳(TOC)含量沿程波动较大,无明显变化规律,说明沿程水动力条件复杂;支流从上游到河口处,总有机碳(TOC)含量基本呈现递减的趋势.在垂向上,不同区域总有机碳(TOC)含量随深度的变化无明显的规律.此外,干流沉积物中总有机碳(TOC)含量与黏土含量呈正相关关系,另外,支流沉积物中总有机碳(TOC)含量与细粉砂含量表现为极显著正相关关系,由于激光粒度仪测试沉积物的结果通常是细粒组分偏粗,所以三峡水库沉积物中TOC含量受粒径较小的物质影响显著.更多还原

【Abstract】 In order to reveal the distribution characteristics of total organic carbon(TOC)in the sediments of the Three Gorges Reservoir,8 and 9 monitoring sections were set up to obtain the columnar sediment samples.Particle size analysis and the TOC content determination were carried out indoors at intervals of 2 cm.Laboratory analysis results show that the main content of TOC maximum value appeared in the Yangtze River Modaoxi,the minimum value appeared in Yunyang,were 1.05%,0.72%,on the whole,the mainstream TOC content along the fluctuations,no significant changes in the law,that along the complicated hydrodynamic conditions;tributaries from the upper reaches to the mouth,TOC content showed the trend of decline.In vertical direction,there is no obvious change of TOC content with depth in different areas.In addition,the content of TOC and clay river sediments showed significant positive correlation between TOC content and fine sand content in the tributary showed a very significant positive correlation between the sediments with laser particle size analyzer is usually the result of fine coarse components;so the content of TOC in Three Gorges Reservoir Sediments by the smaller size of the material effect significant.更多还原