SGER: Dam removal and the response of gravel-bed rivers to sediment pulses

SGER：大坝拆除和砾石河床河流对沉积物脉冲的响应

• 批准号: 0809082
• 负责人: Andrew Wilcox
• 金额: $ 2.99万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0809082&HistoricalAwards=false
• 关键词: SGER; Dam; removal; response; gravel

This study will investigate sediment transport and channel evolution in gravel-bed riversin response to sediment pulses, taking advantage of the field-scale experiment that will becreated by the removal of Milltown Dam on the Clark Fork of the Columbia River, MT. Throughdata collection on pre- and post-dam removal channel conditions and on bedload and suspendedload transport out of Milltown reservoir during high flow periods, this research will addressfundamental questions about fluvial processes, sediment transport and deposition, and damremoval. Several hypotheses will be investigated about how pulses of fine sediment infiltrateinto and affect the mobility of armored river beds, about spatial and temporal patterns ofsediment transport and deposition, and about effective discharges for transporting sedimentpulses. This research will provide an excellent opportunity to evaluate how previous flumeresearch or field studies of small channels, upon which much of what is known about sedimenttransport and related aspects of fluvial processes is based, scale up to larger rivers. Thedata collected here will also be evaluated in the context of the implications of geomorphicresponses and sediment geochemistry for habitat and biological processes.Removal of Milltown Dam, which will begin in spring 2008 and continue the following winter,is especially notable because (1) it is the largest dam removal to date in the United Statesin terms of the volume of reservoir sediment potentially available for downstream transport(approximately 3 million m3; another 2 million m3 are being mechanically removed); (2) thedam is the downstream end of the largest Superfund site in the United States, the Clark ForkComplex, and reservoir sediments are composed largely of contaminated mine tailings; (3) itis occurring on a regionally important river that includes designated Critical Habitat forbull trout, a federally threatened species. Systematic study of this dam removal will thereforehave broader impacts on multiple levels, including for understanding the sediment and metalstransport associated with a significant dam removal, for the insights it lends to upcomingplanned removals of large dams, and for its broader contribution to understanding how gravel-bedrivers respond to increased sediment fluxes. Broader impacts will also derive from the project?sinterdisciplinary nature, whereby analyses of geomorphic processes, geochemistry, hydrology,and fish response will be combined to understand downstream effects of dam removal.This project will help a new faculty member build a research program in fluvial geomorphicprocesses and will directly support one graduate and one undergraduate student. The projectwill also foster ongoing collaboration efforts between University of Montana and Salish-KootenaiCollege, a tribal college in Pablo, MT, whose students will assist field data collection andanalysis under the guidance of the PI. Further, data collection and analysis related to MilltownDam removal will be incorporated into graduate and undergraduate geomorphology and geochemistrycourses, an integration of teaching and research that will be facilitated by the project?sclose proximity to the University of Montana.

这项研究将利用田间尺度实验来研究碎石河河对沉积物脉冲的反应中的沉积物传输和通道演变，这将通过莫特河哥伦比亚河的克拉克叉上的米尔敦大坝去除。在高流量期间，在dam前后的拆除渠道条件以及从米尔敦水库中运输的床上和悬挂载荷运输的遍历收集将解决有关河流过程，沉积物传输和沉积以及Damremoval的基础问题。将研究几个假设，以了解如何渗透性沉积物的脉冲以及如何影响装甲河床的活动性，围绕空间和时间模式运输和沉积的空间和时间模式，以及用于运输沉积物的有效排放。这项研究将为评估以前的Flumeresearch或小型渠道的现场研究提供一个绝佳的机会，而小型渠道或河流过程的相关方面的许多知识是基于大的河流。 Thedata collected here will also be evaluated in the context of the implications of geomorphicresponses and sediment geochemistry for habitat and biological processes.Removal of Milltown Dam, which will begin in spring 2008 and continue the following winter,is especially notable because (1) it is the largest dam removal to date in the United Statesin terms of the volume of reservoir sediment potentially available for downstream transport(approximately 3 million m3; another 2百万M3被机械卸下）； （2）Thedam是美国最大的超级基金遗址的下游端，Clark forkcomplex和储层沉积物主要由受污染的矿山尾矿组成； （3）ITIS发生在一条重要的河流上，其中包括指定的关键栖息地Forbull Trout，这是一种受联邦威胁的物种。因此，对该大坝去除的系统研究将对多个层次产生更广泛的影响，包括了解与大型大坝去除相关的沉积物和金属河流，因为它对即将到来的大型大坝进行了借口的洞察力，以及它对碎石贝甲基对增加沉积物的反应的更广泛贡献。更广泛的影响也将源于该项目，即奔忙于学科的性质，从而将地貌过程，地球化学，水文学和鱼类反应进行分析，以了解大坝去除的下游效应。该项目将帮助一个新的教师在浮力的地球层面上建立一项研究计划，并将一名毕业生和一名毕业生。该项目将促进蒙大拿大学和萨利什·库特纳西尔莱格（Salish-Kootenaicollege）之间的持续合作工作，这是玛特丽的一所部落学院，其学生将在PI的指导下协助现场数据收集和分析。此外，与Milltowndam删除有关的数据收集和分析将纳入研究生和本科地貌学和地球化学，教学和研究的一体化将由该项目促进，这将促进与蒙大拿大学的近似。