辽东半岛东岸泥质区有机物分布特征及其环境指示意义

为研究人类活动及鸭绿江陆源输入对河口海岸及陆架泥质区沉积环境的影响，本文通过对2017年于辽东半岛泥质区东部采集的Q02柱与西部Q04柱进行210Pb定年、粒度、总有机碳、总有机氮、δ13C同位素等指标综合分析，利用Meyers研究模型结合C/N值及δ13C同位素含量分析不同物源有机质贡献率。结果表明:（1）两根柱样TOC与TN含量近百年来逐渐升高，C/N值在9~11之间为海陆混合来源。沉积物主要以粉砂及粘土为主，粉砂含量最高，粘土次之，砂含量较少。（2）有机碳来源占比均呈陆源降低海源升高的特点，分别反映了泥质区东部与西部不同主导因素对海域环境的影响。东部沉积环境主要受流域环境变化与海域共同作用，垦荒、自然灾害、日俄战争等事件造成了植被覆盖降低，水库建设减少了陆源有机碳输入；西部沉积环境主要受沿岸人类活动、水体富营养化的影响，"弛禁"政策导致植被覆盖被破坏，港口修建、水产养殖等活动造成水体营养物质增多，引起海洋环境恶化。

Distribution characteristics of organic matter and their implications on environment change in the mud area on the eastern shore of Liaodong Peninsula

In order to investigate the influence of human activities within the Yalu River catchment, in terms of the import of terrestrial inputs from the Yalu River, on the sedimentary environment of the estuary and continental shelf mud deposition area, two sediment cores, Q02 and Q04, were collected from the mud deposition area of the eastern Liaodong Peninsula.Subsequently, the content of 210Pb dating, grain size, total organic carbon (TOC), total organic nitrogen (TN), stable carbon isotope (δ13C) were analyzed; finally, the C/N ratio and δ13C value were used to analyze the contribution of different organic matter source.The results show that:(1) TOC and TN were gradually increased during the past 100 years.The C/N ratio ranged from 9 to 11, indicating that the organic carbon is characterized by terrestrial and marine mixing sources. (2) The organic carbon proportions originating from terrestrial and marine source indicated a decreasing and increasing trends, respectively, implying that the eastern and western of the study area suffered from different controlling factors.In the eastern area, the sedimentary environment is mainly affected by catchment environment change and land-sea interaction:reclamation, natural disasters and wars caused the vegetation cover reduced, and the reservoir construction decreased the input of terrestrial organic carbon.The sedimentary environmentof eastern area is mainly controlled by human activities and water eutrophication:"Closure" Policies result in the destruction of vegetation cover, and the ports construction, aquaculture lead tothe increase of nutrients in the water bodies, which cause deterioration of the marine environment.