Fine Particle Migration and Solute Fluxes in Sediment Beds: Analysis of Sediment Structural Dynamics Using 3D Micro-Tomography

沉积物床中的细颗粒迁移和溶质通量：使用 3D 显微断层扫描分析沉积物结构动力学

• 批准号: 0310657
• 负责人: Aaron Packman
• 金额: $ 23.56万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0310657&HistoricalAwards=false
• 关键词: Fine; Particle; Migration; Solute; Fluxes

0310657Packman The proposed work will advance our understanding of sedimentary processes by combining detailed observations of bulk sediment transport with fine-scale measurements of the resulting three-dimensional sedimentary structure. These processes will be studied in a recirculating flume in order to provide control of flow conditions and to allow direct observation of sediment transport processes. The Advanced Photon Source at Argonne National Lab will be used to perform 3D X-ray micro-tomography and X-ray fluorescence mapping on intact sediment cores taken from the flumes. The primary goals of these observations will be to examine the evolution of bulk sediment structure, specifically the development of heterogeneous depositional structures. Sediment mixing will also be determined from observations of the redistribution of tracer particles that will be specifically synthesized to provide good contrast for X-ray tomography. A conservative solute will be used to assess pore water fluxes resulting from stream-subsurface flow coupling. Fundamental models will be applied to assess the migration of fine particles within the sediment bed and the resulting development of heterogeneous sedimentary conditions. This study will provide key understanding of the linkage between hydrologic processes and sediment structure. Graduate and undergraduate students involved in this project will gain experience with detailed, process-oriented, interdisciplinary environmental studies. In addition, active international collaboration and student exchange programs will encourage project participants to engage in global scientific endeavors. Finally, involvement of K-12 teachers and use of project laboratory facilities for educational tours and demonstrations will disseminate project results to pre-college students and encourage them to pursue similar studies.

提出的工作将通过将大块沉积物输运的详细观测与由此产生的三维沉积结构的精细测量相结合，推进我们对沉积过程的理解。这些过程将在一个循环水槽中进行研究，以便控制流动条件，并允许直接观察沉积物的输送过程。阿贡国家实验室的先进光子源将用于对从水槽中取出的完整沉积物岩心进行3D x射线微断层扫描和x射线荧光测绘。这些观测的主要目的是研究大块沉积结构的演化，特别是非均质沉积结构的发展。沉积物混合也将通过观察示踪颗粒的再分布来确定，这些示踪颗粒将被专门合成，以提供x射线断层扫描的良好对比。一个保守的溶质将被用来评估由河流-地下流动耦合引起的孔隙水通量。将应用基本模型来评估沉积物床内细颗粒的迁移以及由此产生的非均质沉积条件的发展。这项研究将为了解水文过程与沉积物结构之间的联系提供关键的理解。参与该项目的研究生和本科生将获得详细的、以过程为导向的、跨学科的环境研究经验。此外，积极的国际合作和学生交流计划将鼓励项目参与者参与全球科学努力。最后，K-12教师的参与和使用项目实验室设施进行教育参观和示范，将项目成果传播给大学预科学生，并鼓励他们进行类似的研究。