闽江下游入海物质形态及通量研究

The Minjiang River is the largest river in south eastern China. It is next only to Yangtze and Pearl River and is the third largest by waterflow over the country, with an average discharge of 88.68 billion cubic meters in 2010. The flux and environmental quality of Minjiang material is great important to the environment of its downstream and the Taiwan Strait. Compare to other rivers in the domestic, the sediment load of Minjiang easily affected by climate change which could be allocate to its subtropical location and mountain stream nature. The research project is design to explore the content variation of substances pour into the sea in each process and possible corresponding impact factors, based on "From Source to Sink" idea. We propose to target a specific complex system including Shuikou reservoir - tidal river - urban river watercourse - the turbidity maximum zone in estuary to do the systematic sampling, as well as to get flux of dissolved and particle of material transported into sea in different hydrological regimes. We will monitor the typical elements of the different forms, especially proxy elements of chemical weathering, nutrients, and pollutants simultaneously. In particular, retention effect in the reservoir, tidal effect of estuary, filter effect of the turbidity maximum zone and the impact of human activities will all be integrated into consideration, in order to provide a comprehensive understanding of the mechanism controlled the flux of material and to lay the foundation for in-depth studies. The project has a practical significance for both environmental protection and ecological restoration in the River and its adjacent area. It also has important scientific merit in dealing with climate change and will move the understanding of Chinese river systems onto a new plane

闽江是我国东南沿海最大的河流，2010年径流量为886.75亿方，居全国第3位，仅次于长江、珠江。闽江入海物质的质量和通量对其下游河口区及台湾海峡的环境有重要意义。闽江是我国处在亚热带区域的一条具有山间溪流性质的大河，输沙量变化受气候影响很大，与国内其它河流有较大的差异。 本项目利用"从源到汇"的研究理念，探讨入海物质在各环节中的含量变化及其可能的影响因素。针对水口水库-感潮河段-城市河道-河口最大浑浊带这一复杂系统，进行系统采样，获取不同水文状态下溶解态和颗粒态物质的入海通量。同时通过对不同形态中的典型元素，尤其是化学风化指标元素、营养盐、污染物等的分析，就水库的滞留效应、人类活动影响、河口区的潮汐效应、最大浑浊带的过滤器效应等进行综合研究，为进行更深入的研究奠定基础。 本项目对闽江的及其邻近海域环境保护和生态修复具有现实意义，对全面认识我国河流系统，应对气候变化具有重要的科学意义。

闽江是位于亚热带的山间溪流型大河，物质输送受多种因素的综合影响。为了解地球化学因素对闽江入海物质的影响，本项目以“水口水库—闽江—闽江口—邻近海域”作为系统研究，按流域大面调查与河口加密观察的方式布设了32个站位，分3个外业组,在丰水期、次丰水期、平水期、枯水期4个阶段进行准同步观察。.项目把水—悬浮物—沉积物作为一个研究整体，分析水体—悬浮物—沉积物（包括全样、粉砂组分、粘土组分）中物质组分或地球化学指标，涉及现场分析及实验室分析的水质项目44项、悬浮物分析项目58项、沉积物分析项目65项，要素包括粒度、矿物、常量元素、微量元素、营养盐、重金属、多种地球化学指标。.课题研究从源到汇、从水体到沉积物。既有湖泊型的水库与坝下段的对比——水库的滞留效应，又有支流型河口与入海口的对比，河道分流与汇合的影响、城市河道及其人类活动的影响，潮汐作用对感潮河段、河口最大浑浊的影响等。物质的迁移不仅与物质本身的性质有关，也与气候效应、水体复氧与水体自净、生物作用与颗粒物行为、过滤器效应等关联。研究中以物质从源到汇的迁移、转化、沉降规律研究为主线，结合地质背景和水文资料与社会环境状况等的影响，从元素（要素）的性质及其与环境、输运条件的关系、地球化学作用对元素迁移的影响等入手，探讨闽江物质的迁移、输运过程中各类因素的作用及其对入海通量的影响。.课题组还通过水体REE测试的分析条件试验与改进，解决了复杂水体中微量元素的测定难题。在综合研究的基础上，估算了研究时段闽江部分溶解态和颗粒态物质的入海通量。.项目的特点是区域大、代表性强、载体多、指标丰富、季节全、数据可比性强、研究潜力大，可为闽江的深入研究提供有效的基础资料。