Cumulative effects on sediment and associated chemical fluxes at the landscape scale: the role of geomorpological connectivity

景观尺度上沉积物和相关化学通量的累积效应：地貌连通性的作用

• 批准号: 341995-2013
• 负责人: Owens, Philip
• 金额: $ 1.97万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549571
• 关键词: Cumulative; effects; sediment; associated; chemical

One of the current research themes in environmental science is how natural and anthropogenic pressures or stressors - such as climate change, land-use activities like forestry and mining, and natural events like wildfires - affect water resources and aquatic ecosystems. This interest is driven by the recognition that most, if not all, water bodies are affected by multiple stressors (often termed cumulative effects) that impact water quantity (e.g. water flows) and water quality (e.g. chemistry, sediment concentrations). The objective of this research project is to determine the cumulative effects of multiple stressors on the environment by focusing on the Quesnel River Basin (QRB, ca. 12,000 km2) in central British Columbia. The overall research project will specifically focus on how geomorphological connectivity (e. g. linkages between land and rivers, and linkages within channels) influences the transfer of sediment and associated chemicals - like trace metals (i.e. arsenic, copper, zinc), nutrients (e.g. phosphorus) and particulate carbon - due to stressors acting in the QRB. One project will evaluate the role of storage elements (specifically glacial forefields, riparian buffers, floodplains, and channel beds) in controlling how sediment and associated chemicals move through landscapes that have been influenced by climate change and land-use activities. In particular, this project will determine if such storage elements attenuate and/or modify material flows and fates. A second project will employ a nested monitoring program in conjunction with sediment tracers, to follow the movement of sediment and chemicals downstream of specific land-use activities such as agriculture, forestry and mining. A third project will use existing spatially distributed models to examine the role of geomorphological connectivity on sediment and associated chemical responses to stressors at the watershed-scale, utilizing the empirical information obtained from the first two projects and an existing GIS platform available for the QRB. The work will provide an improved understanding of how watersheds respond to cumulative effects in a rapidly changing world, which will help to protect water resources and aquatic habitats in Canada.

环境科学当前的研究主题之一是自然和人为压力或应激源（例如气候变化、林业和采矿等土地利用活动以及野火等自然事件）如何影响水资源和水生生态系统。这种兴趣是由于认识到大多数（如果不是全部）水体都受到多种压力源（通常称为累积效应）的影响，这些压力源会影响水量（例如水流）和水质（例如化学成分、沉积物浓度）。该研究项目的目标是通过关注不列颠哥伦比亚省中部的克内尔河流域（QRB，约 12,000 平方公里）来确定多种压力源对环境的累积影响。整个研究项目将特别关注地貌连通性（例如陆地和河流之间的联系以及渠道内的联系）如何影响沉积物和相关化学物质的转移 - 例如微量金属（即砷、铜、锌）、营养物（例如磷）和颗粒碳 - 由于作用于 QRB 的压力源。一个项目将评估封存要素（特别是冰川前田、河岸缓冲区、洪泛区和河床）在控制沉积物和相关化学物质如何穿过受气候变化和土地利用活动影响的景观中的作用。特别是，该项目将确定此类存储元素是否会减弱和/或改变物质流和命运。第二个项目将采用嵌套监测程序与沉积物示踪剂相结合，跟踪农业、林业和采矿等特定土地利用活动下游的沉积物和化学品的移动情况。第三个项目将利用从前两个项目获得的经验信息和 QRB 现有的 GIS 平台，利用现有的空间分布模型来研究地貌连通性对沉积物的作用以及流域范围内压力源的相关化学反应。这项工作将更好地了解流域如何应对快速变化的世界中的累积影响，这将有助于保护加拿大的水资源和水生栖息地。