Collaborative Research: Role of interfacial turbulence in hyporheic exchange and fine particle dynamics

合作研究：界面湍流在潜流交换和细颗粒动力学中的作用

• 批准号: 1215898
• 负责人: Aaron Packman
• 金额: $ 25.58万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1215898&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; interfacial; turbulence

Collaborative Research: Role of interfacial turbulence in hyporheic exchange and fine particle dynamicsAaron Packman, Northwestern UniversityJames Best, Kenneth Christensen, Marcelo Garcia University of Illinois at Urbana-ChampaignIt is essential to improve understanding of interactions between surface water flows and underlying porewaters in order to advance our ability to assess connectivity in aquatic ecosystems, evaluate the propagation of carbon, nutrients, and contaminants through river networks, and predict the net effects of human modification of watersheds. In previous NSF-supported research, the investigators found that hydrodynamic interactions caused rapid exchange between rivers and underlying porewater, along with ongoing deposition and resuspension of fine particles. These processes are expected to substantially influence downstream migration of solutes and particles in river networks. Unfortunately, very little information is available on the hydrodynamic mechanisms that control this behavior because it has been extremely difficult to directly measure solute and particle dynamics in porewaters. The objectives of the current project are to improve fundamental understanding of hydrodynamic interactions between freestream flows and porewaters, and to use the information to transform conceptual and quantitative models for solute and particle dynamics in rivers. The investigators will use an array of new flow visualization technologies to obtain direct observations of fluid exchange between rivers and streambeds, and the associated fluxes of solutes and fine suspended particles. The results will be used to identify the main fluid flow processes responsible for solute and particle transport across porous environmental interfaces. This work will yield improved models for the surface-subsurface flow continuum, as well as new probabilistic models for downstream solute and particle transport. The major scientific contributions of this work will be an improved characterization of fundamental mechanisms of flow coupling between rivers and riverbeds, and new models for the migration of dissolved and suspended materials in rivers. Such models are essential to enable the prediction of large-scale, long-term dynamics required for sustainable management of river systems. The project will characterize important components of interfacial flux currently missing from solute transport models, and provide critical new observations of fine particle deposition and resuspension. This information is needed to address many pressing problems in freshwater systems, including contaminant interactions with sediments, protection of ecological diversity within rivers, nutrient retention and carbon processing in rivers, and waterborne disease transmission. The models developed in this project can be used to evaluate the factors that produce high risks of transmission of contaminants and waterborne diseases, and thereby improve management of watersheds to minimize these risks. The project will also contribute to longer-term sustainability of drinking water resources and aquatic ecosystems by improving our capability to predict long-term biogeochemical and ecological dynamics in rivers. The project will contribute to the broader education of students and the public by incorporating project results into major outreach efforts at Northwestern University and the University of Illinois. The focus will be on helping K-12 students and neighborhood communities to understand how river processes influence water quality, human health, and natural ecosystems. The investigators will also work with several university student groups to develop a new program involving regular on-campus activities and mentoring for students from populations underrepresented in the sciences. Overall, ~1500 K-12 students and adults each year (~4,500 over the lifetime of the project) will be engaged in laboratory activities and discussions of the significance of hydrological processes to sustainability.

协作研究：界面湍流在低音交换中的作用和精细的粒子动力学和精细的粒子动态，西北大学女士最佳，肯尼斯·克里斯滕森，肯尼斯·克里斯滕森，伊利诺伊州马塞洛·加西亚大学在urbana-champaignit上的作用对于改善对逐步的能力的互动，以提高对ecos的互动的理解，以评估这一能力，以提高对等级的互动的理解通过河网络，碳，营养素和污染物，并预测人类修饰的分水岭的净影响。在以前的NSF支持的研究中，研究人员发现流体动力学相互作用引起了河流与潜在的孔隙水之间的快速交换，以及持续的沉积和细颗粒的重悬。预计这些过程将显着影响河网络中溶质和颗粒的下游迁移。不幸的是，关于控制这种行为的流体动力机制的信息很少，因为很难直接测量毛孔渗水中的溶质和粒子动力学。当前项目的目标是提高对自由流和毛孔之间流体动力相互作用的基本理解，并使用信息来转换河流中溶质和粒子动力学的概念和定量模型。研究人员将使用一系列新的流动可视化技术来获得对河流和流床之间流体交换的直接观察，以及相关的溶质和细悬浮颗粒的通量。结果将用于确定负责溶质和粒子在多孔环境界面的运输的主要流体流动过程。这项工作将为表面表面流连续体提供改进的模型，以及用于下游溶质和颗粒传输的新概率模型。这项工作的主要科学贡献将是对河流和河床之间流动耦合的基本机制的改进，以及用于迁移河流中溶解和悬浮材料的新模型。 这样的模型对于能够预测河流系统可持续管理所需的大规模长期动态至关重要。该项目将表征当前溶质传输模型中当前缺少的界面通量的重要组成部分，并提供了精细颗粒沉积和重悬的新观察结果。需要此信息来解决淡水系统中的许多紧迫问题，包括与沉积物的污染物相互作用，河流内生态多样性的保护，河流中的养分保留和碳加工以及水传播疾病的传播。该项目中开发的模型可用于评估产生污染物和水源性疾病的高风险的因素，从而改善对流域的管理以最大程度地减少这些风险。该项目还将通过提高我们预测河流长期生物地球化学和生态动态的能力，从而有助于饮用水资源和水生生态系统的长期可持续性。 该项目将通过将项目结果纳入西北大学和伊利诺伊大学的主要外展工作中，从而为学生和公众提供更广泛的教育。重点将是帮助K-12学生和社区社区了解河流过程如何影响水质，人类健康和自然生态系统。调查人员还将与几个大学生团体合作，制定一项新计划，涉及定期的校园活动，并为来自科学人群不足的学生提供指导。总体而言，每年约有1500个K-12学生和成人（在项目的一生中约有4,500名）将参与实验室活动，并讨论水文过程对可持续性的重要性。