雅鲁藏布江和澜沧江全物质通量监测研究

Water and sediment as well as substances loaded by them constitute important lineages in river systems. All material fluxes in rivers are not only the complehensive reflection to the transport intensity of various materials, but also the fundamentals for river health diagnosis. In view of the multiple-material monitoring problems encountered in the the Southwest areas characterized with high altitude, low temperature and low air pressure, we propose simultaneous monitoring of all material fluxes in the exsiting hydrological stations in Yarlung Zangbo River and Lantsang River, respectively. The monitored information includes the matched idices on biogenic substances, inorganic elements, trace organic pollutants, isotope, green house gas, microorganism and zoobenthos. Based on historical data and existing monitoring system, the monitoring-analytical platform on all material fluxes would be established for plateau river systems. Moreover, spatial-temporal variations of water, sediment and other substances in water-sediment media will be investigated. Other important issues to be studied include sources and destinations of biogenic substances; concentration, speciation, phase and transport characteristics; the interaction mechanism among various abiotic materials; the community of microorganisms and zoobenthos specially existed in the alpine region and their responses to changing biogenic substances. This study is a first attempt on simultaneous monitoring and analysis on all material fluxes in Southwest rivers, which will fill in gap in the study area and provide effective demonstration for other similar rivers.

河流中水沙及其负载物质与水生生物构成了河流系统重要的物质谱系。河流全物质通量不仅是各类物质输移强度的综合反映，而且是河流健康评估的重要基础。本项目针对西南源区高海拔、低气温、低气压自然环境下河流物质监测基础薄弱的突出问题，拟选择雅鲁藏布江和澜沧江，依托现有水沙与常规水质监测诸站，同步获取水-沙介质中生源物质、无机元素、天然有机物、痕量有机物、同位素、温室气体、微生物、底栖动物等时空匹配的监测信息。基于现有水文-水质历史数据及监测系统，进一步建立适应高寒条件的全物质通量监测与检测分析技术体系，研究河流水沙及其负载物质的时空分布规律，初步解析生源物质的来源与归宿，分析物质数量-赋存形态-相态及其输运特征，探索主要非生物物质之间的相互作用机理，揭示高寒条件下微生物、底栖动物群落结构及其对生源物质变化的响应机制。本研究将弥补我国西南河流全物质通量研究的空白，同时也为其他类似河流提供有效示范。

河流中水沙及其负载物质与水生生物构成了河流系统重要的物质谱系。本项目针对西南源区高海拔、低气温、低气压自然环境下河流物质监测基础薄弱的突出问题，选择雅鲁藏布江和澜沧江为研究区域，建立适应高寒条件的全物质通量监测与检测分析技术体系，同步监测并研究河流水沙及其负载物质的时空分布规律，初步解析生源物质的来源与归宿，揭示高寒条件下微生物、底栖动物群落结构及其对生源物质变化的响应机制。项目取得了如下成果：（1）构建了高原河流全物质通量监测-检测体系，实现了34类788项指标的同步监测-检测，获得了16万数据（100T容量），为深入探索大河不同物质之间的关系奠定基础。基于雅鲁藏布江和澜沧江环境样品获得的实验数据，初步探讨了微生物、藻类和底栖动物群落结构对生源物质的响应。（2）系统地研究了高原河流各物质要素随距离的变化特征，发现澜沧江水体和沉积物中非生物要素和生物要素的相似度均随距离增加呈现衰减趋势；雅鲁藏布江的沉积物各要素的相似度随距离的增加变化都不明显；雅江水体微生物、底栖动物、生源物质、温室气体等相似度呈衰减趋势，而重金属、抗生素随距离增加变化不大。（3）采用高通量测序技术，构建了河流水沙体系中细菌、藻类群落的时空分布格局研究方法，解决了传统方法鉴定难度大、受主观因素影响大的问题，揭示了不同地貌单元（山地、丘陵、盆地、丘陵-山地、平原）以及大坝对水体和沉积物中微生物群落的影响机制。本研究成果能够弥补我国西南河流全物质通量研究的空白，同时也为其他类似河流提供有效示范。