Collaborative Research: Linking scales of geomorphology and solute transport in river corridors

合作研究：将河流廊道中的地貌尺度和溶质迁移联系起来

• 批准号: 0810140
• 负责人: Judson Harvey
• 金额: $ 0.93万
• 依托单位: UNITED STATES DEPT OF GEOLOGICAL SURVEY
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0810140&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; scales; geomorphology

PIs: Aaron Packman (Northwestern University), Douglas Jerolmack (University of Pennsylvania), Jud Harvey (U.S. Geological Survey) Overview: Solute transport in rivers is a complex problem influenced by both hydrologic and geomorphic dynamics. It is important to be able to predict the interactions of hydrologic dynamics, geomorphic dynamics, and solute transport in order to improve assessment of long-term average biogeochemical processing rates in river systems. Stream-subsurface hydrologic interactions are modulated by surface morphology and strongly affect solute transport in both streams and pore waters, thereby controlling a very wide range of biogeochemical processes. Here we propose to obtain a unique new data set encompassing observations of both fluvial morphodynamics and solute transport in a sand-bed river subject to frequent high-flow and sediment-transport events. We also propose to develop new theory to allow scaling relationships previously observed in both geomorphology and surface-groundwater interactions to be incorporated into a model for long-term average solute transport in rivers. The model will be applied to the study site by incorporating observed statistics of stream flow variations and channel morphology, and will be tested using direct observations of both solute penetration into the subsurface and net downstream solute transport averaged over a range of time scales. Intellectual Merit: The intellectual merit of this work lies in advancing fundamental understanding of the linkage between stream hydrology, fluvial morphodynamics, surface-groundwater interactions, and solute transport in rivers. This is an exceedingly complex problem as it involves not only turbulent flow-boundary interactions, but also sediment transport and pore fluid flow in the highly heterogeneous near-stream environment. Here we will synthesize numerous recent observations and hypotheses developed separately in hydrology and geomorphology in order to ascertain how the linkage between flow dynamics and morphodynamics in rivers controls solute transport over various spatial and temporal scales. While it is now generally recognized that such synthesis needs to be done in order to assess the behavior of environmental systems in an integrated fashion, such integration has rarely been achieved in practice. By developing new theory that takes advantage of commonality in geomorphic and hydrologic scaling relationships, we enable explicit evaluation of the integrated process that control solute transport dynamics over a variety of spatial and temporal scales in river corridors. Broader Impacts: The proposed effort will contribute very broadly to environmental science and the associated management of water resources and aquatic ecosystems. Further, through a variety of synergistic activities we will also realize numerous broader impacts in human resource development and in the scientific community at large. The project results will provide significant, necessary capability to evaluate the migration of a wide range of important solutes in river systems. There is a critical need for tools that can be used to predict the linkage of morphological variations (e.g., land-use changes) and long-term average transport behavior under variable hydrologic forcing (natural flow variability and alternative climate change scenarios). Therefore the project results can be expected to not only contribute detailed understanding of river dynamics, but also to have very broad impacts in supporting analysis of the migration and processing of carbon, nutrients, contaminants, and a range of other important substances in river systems. Essentially, the project efforts provide a critical step towards scientifically based sustainable management of freshwater resources. We will further enhance these general contributions by supporting the broader scientific community working on these problems. We will archive the unique field data set that we will acquire, and make it publicly available to other theoreticians and modelers to facilitate broader development and testing of models for flow and transport in river corridors. We will also facilitate scientific discourse, and particularly synthesis of scientific results to address policy and management questions, by convening multiple, directed interdisciplinary sessions at major technical conferences, and by translating project results directly into the broader Hydrologic Synthesis activity currently sponsored by NSF. Finally, we will realize broad contributions to human resource development by training numerous young investigators through this work, by engaging in synergistic and collaborative international activity, and by using project results to further our ongoing efforts to encourage pre-college students, and particularly students from under-represented minorities, to enter careers in science

PIS：Aaron Packman(西北大学)，Douglas Jerolmack(宾夕法尼亚大学)，Jud Harvey(美国地质调查局)概述：河流中的溶质运移是一个受水文和地貌动力学影响的复杂问题。为了改进对河流系统长期平均生物地球化学处理速率的评估，能够预测水文动力学、地貌动力学和溶质运移的相互作用是很重要的。河流-地下水文相互作用受地表形态的调节，并强烈影响河流和孔隙水中的溶质运移，从而控制着非常广泛的生物地球化学过程。在这里，我们建议获得一个独特的新数据集，包括对频繁的高流量和泥沙输送事件下沙床河流的河流地貌动力学和溶质运移的观测。我们还建议发展新的理论，将以前在地貌和地表水-地下水相互作用中观察到的比例关系纳入到河流长期平均溶质运移的模型中。该模型将通过结合观测到的水流变化和河道形态的统计数据应用于研究地点，并将通过直接观测溶质向地下渗透和在一系列时间尺度上平均的下游净溶质运移来进行检验。智力价值：这项工作的智力价值在于促进了对河流水文学、河流地貌动力学、地表-地下水相互作用和河流中溶质运移之间的联系的基本理解。这是一个极其复杂的问题，因为它不仅涉及湍流-边界相互作用，而且涉及高度不均匀的近流环境中的泥沙运移和孔隙流体流动。在这里，我们将综合最近在水文学和地貌学中分别发展的大量观测和假说，以确定河流中水流动力学和地貌动力学之间的联系如何在不同的空间和时间尺度上控制溶质运移。虽然现在普遍认识到，为了以综合的方式评估环境系统的行为，需要进行这种综合，但在实践中很少实现这种综合。通过发展新的理论，利用地貌和水文尺度关系的共性，我们能够明确地评估控制河流走廊中各种空间和时间尺度上的溶质运移动力学的综合过程。更广泛的影响：拟议的努力将对环境科学以及水资源和水生态系统的相关管理作出非常广泛的贡献。此外，通过各种协同活动，我们还将在人力资源开发和整个科学界实现许多更广泛的影响。该项目的成果将为评估各种重要溶质在河流系统中的迁移提供重要而必要的能力。迫切需要能够用来预测地形变化(例如，土地利用变化)与不同水文强迫(自然流量变化和气候变化情景)下的长期平均运输行为之间的联系的工具。因此，预计项目成果不仅有助于对河流动态的详细了解，还将对支持分析河流系统中碳、营养物质、污染物和一系列其他重要物质的迁移和处理产生非常广泛的影响。从本质上讲，这些项目的努力为淡水资源的科学可持续管理迈出了关键一步。我们将通过支持更广泛的科学界在这些问题上的工作来进一步加强这些普遍贡献。我们将把我们将获得的独特的现场数据集存档，并将其公开提供给其他理论家和模型师，以促进更广泛的河流廊道水流和运输模型的开发和测试。我们还将促进科学讨论，特别是科学成果的综合，以解决政策和管理问题，在主要技术会议上召开多个有针对性的跨学科会议，并将项目成果直接转化为目前由国家科学基金会赞助的更广泛的水文综合活动。最后，我们将通过这项工作培训许多青年研究人员，通过参与协同和协作的国际活动，并通过利用项目成果进一步推动我们正在进行的努力，鼓励大学预科学生，特别是来自代表性不足的少数族裔的学生，进入科学职业生涯，从而实现对人力资源开发的广泛贡献。