Will climate change affect hyporheic processes in arctic streams? An assessment of interactions among geomorphology, hydrology, and biogeochemistry in Arctic stream networks

气候变化会影响北极溪流的潜流过程吗？

• 批准号: 0327440
• 负责人: William Bowden
• 金额: $ 60.87万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0327440&HistoricalAwards=false
• 关键词: Will; climate; change; affect; hyporheic

ABSTRACTBowdenOPP-032740 This is a collaborative proposal by Principal Investigators at the University of Vermont, Boise State University and Utah State University. The goal of this project is to assess how geomorphology and seasonal changes in the thawed region of soil and sediment around the open channel (i.e.; the thaw bulb) control hydraulic and biogeochemical dynamics in the hyporheic zone of Arctic streams. The premise is that: a) stream geomorphology sets a physical template that controls the seasonal development of the sub-stream active layer (or thaw bulb) around Arctic streams; b) the thaw bulb extent controls the potential for development of the hyporheic zone, and c) the hyporheic zone substantially contributes to carbon (C), nitrogen (N) and phosphorous (P) processing in streams. The Principal Investigators anticipate that climate change in the Arctic has the potential to significantly alter the thaw bulb and hyporheic dynamics through its influences directly on precipitation, runoff, average annual temperature, and thaw season duration, and indirectly on stream geomorphology. To address this central hypothesis, they propose four objectives: 1. Select and characterize stream reaches that represent the range of geomorphologic conditions in rivers of the North Slope. 2. Monitor the sub-stream thaw bulb size through the thaw season using ground penetrating radar and subsurface temperature measurement in several stream cross-sections within each reach. 3. Conduct repeated hyporheic exchange studies (stream solute addition experiments) through the thaw season in each reach to determine hyporheic hydraulic characteristics. 4. Conduct repeated measures of nutrient (N and P) concentrations and turnover time in the hyporheic zone through the thaw season in each reach to determine biogeochemical characteristics. These objectives will be addressed through a combination of field monitoring (thermistor arrays, hyporheic sampling), field experiments (solute additions), and modeling (groundwater transport and transient storage) efforts. This research is important because there is no reported literature on the structure and functions of the hyporheic zone in Arctic systems. Considerable research in temperate regions suggests that hyporheic zones are critical components of stream ecosystems. A significant portion of the primary production in streams may be supported by nutrients regenerated from hyporheic processes. This regeneration is dependent on organic matter inputs (both autochthonous and allochthonous). Thus, hyporheic processing is also important in understanding how streams modify carbon, nitrogen, and phosphorous transport across landscapes. Research which quantifies these important functions in Arctic streams is non-existent.Broader Impacts: Research on this subject is important as a direct input to our understanding of the ecological functions of Arctic streams. Given that rivers are the conduits that link land to the ocean, then processes within streams that modify material transport must be important to understanding how runoff from land affects oceans. Furthermore, if climate change affects the rate or extent of in-stream processing, then there may be important impacts on the transport of materials from land to the ocean, which this research would begin to address. Therefore, these studies are essential to provide data and knowledge that will be of use to other scientists, policy makers, resources managers, and ultimately to community stakeholders.

AbstractBowdenopp-032740这是佛蒙特大学，博伊西州立大学和犹他州大学的首席研究人员的合作提案。 该项目的目的是评估开放通道周围土壤和沉积物解冻区域的地貌和季节变化如何控制北极流的液压和生物地球化学动力学。 前提是：a）溪流地貌设置了一个物理模板，该模板控制着北极流周围的子流动层（或解冻灯泡）的季节性开发； b）融化的灯泡范围控制着低血压区的发展潜力，c）低音区域基本上有助于碳（C），氮（N）和磷（P）处理。 首席研究人员预计，北极的气候变化有可能通过直接影响降水，径流，平均年温度和融化季节持续时间来显着改变融化的灯泡和低音动力学，并间接地对流地貌学。 为了解决这一中心假设，他们提出了四个目标：1。选择和表征代表北坡河流中地貌条件范围的流到达。 2。使用地面穿透性雷达和地下温度测量在每个河段内的几个溪流截面中，监测子流解冻灯泡的大小。 3。通过融化季节进行重复的低音交换研究（流溶质添加实验），以确定低音液压特征。 4。在每个覆盖范围内通过融化季节进行养分（N和P）浓度的重复测量，以及在融化季节中的周转时间，以确定生物地球化学特征。这些目标将通过现场监测（热敏电阻阵列，低音采样），现场实验（溶质添加）和建模（地下水传输和瞬态存储）的组合来解决。这项研究很重要，因为没有关于北极系统中低潮区的结构和功能的报道。 在温带地区进行大量研究表明，低血压区是流生态系统的关键组成部分。 溪流中主要产量的很大一部分可以由低流过程再生的营养所支持。 这种再生取决于有机物输入（自围候和异源）。 因此，低流向处理对于理解溪流如何修饰碳跨景观的碳，氮和磷转运也很重要。 量化这些重要功能在北极流中的研究是不存在的。Broader的影响：对此主题的研究至关重要，这是我们对北极流的生态功能的理解的直接输入。 鉴于河流是将土地与海洋联系起来的导管，因此在溪流中进行了修改物质运输的过程对于了解土地径流如何影响海洋至关重要。 此外，如果气候变化会影响流入过程的速度或程度，那么可能会对从土地到海洋的运输产生重要影响，这项研究将开始解决。 因此，这些研究对于提供将用于其他科学家，政策制定者，资源经理以及最终向社区利益相关者使用的数据和知识至关重要。