Collaborative Research: Unlocking The Seismic Signature Of Rivers

合作研究：解锁河流的地震特征

• 批准号: 1148176
• 负责人: Colin Stark
• 金额: $ 6.39万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1148176&HistoricalAwards=false
• 关键词: Collaborative; Research; Unlocking; Seismic; Signature

Gravel and cobble transport by rivers governs channel change, and is therefore of great importance to geomorphologists and river engineers. The most commonly used approaches to estimating bedload transport rates are empirically calibrated relationships based on flume experiments. However, it is difficult to assess how effectively such relationships predict transport rates during extreme events in large rivers because quantitative measures of bedload transport are labor intensive and, at high flows, often dangerous to obtain. For logistical reasons, most bedload studies have been carried out in small mountain streams. Particle impacts on the river bed transfer momentum, which in turn generates elastic (seismic) waves. Therefore, seismology (the study of elastic waves in the Earth) can potentially constrain bedload transport rates in rivers. Taking advantage of a well-instrumented catchment with independent constraints on when and at what rate sediment moves in the channel, we will deploy an array of seismometers to test theoretical predictions for the generation of seismic waves from bedload sediment impacts with the bed during transport. Understanding more clearly when and at what rate coarse sediment moves in river channels is essential for planning infrastructure in and adjacent to rivers (e.g., bridges, dams, roads). Approaches to predicting coarse sediment transport are typically developed in controlled settings and can be inaccurate in large floods, when it is most critical to be able to predict sediment movement. Using a novel application of an existing science (seismology), we are developing an approach to measuring bedload transport in large rivers without requiring the deployment of any instrumentation in the river. This work has the potential to greatly improve our capacity to cheaply, safely, and efficiently monitor sediment movement in rivers while simultaneously advancing understanding of the processes influencing bedload transport rates in rivers. Additionally, this project will have an outreach component in which an undergraduate geology class will conduct a sediment transport monitoring exercise using the approach developed here.

河流的砾石和鹅卵石运输控制着渠道的变化，因此对地貌学家和河流工程师至关重要。根据水槽实验，最常用的估计床载运输速率的方法是经验校准的关系。 但是，很难评估这种关系如何有效地预测大河流中极端事件中的运输速率，因为床负荷运输的定量测量是劳动力密集的，并且在高流量下通常会危险地获得。出于后勤原因，大多数卧床研究都是在小型山流中进行的。粒子会影响河床转移动量，从而产生弹性（地震）波。因此，地震学（对地球中的弹性波的研究）可能会限制河流中的床载运输速率。 利用备受纪录的集水区，对何时和以速率沉积物在频道中的何时和以哪种速度的方式移动，我们将部署一系列的地震米，以测试理论预测，从而在运输过程中从床载沉积物上产生地震波产生地震波。 更清楚地了解何时及以什么速率的河道中的粗沉积物移动对于规划河流（例如桥梁，大坝，道路）的基础设施至关重要。 预测粗沉积物传输的方法通常是在受控的环境中开发的，在大洪水中可能不准确，当能够预测沉积物运动至关重要时。 使用现有科学（地震学）的新颖应用，我们正在开发一种方法来测量大河中的床载运输，而无需在河中部署任何仪器。 这项工作有可能极大地提高我们廉价，安全和有效监测河流中的沉积物运动的能力，同时促进对影响河流床负载运输速率的过程的理解。 此外，该项目将有一个外展部分，其中本科地质课将使用此处开发的方法进行沉积物运输监测。