Collaborative Research: Defining controls on incisional avulsions in alluvial basins

合作研究：确定冲积盆地切口撕脱的控制措施

• 批准号: 1123847
• 负责人: Doug Edmonds
• 金额: $ 11.23万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2012-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1123847&HistoricalAwards=false
• 关键词: Collaborative; Research; Defining; controls; incisional

Collaborative Research: Defining controls on incisional avulsions in alluvial basinsRiver avulsion occurs when water is diverted out of a river and creates a new channel on the surrounding floodplain. The associated flooding can be catastrophic for people living along rivers, but hazard mitigation is difficult because models cannot predict the timing, location, or style of river avulsion. Incisional avulsion occurs when a new river channel is established through erosion rather than deposition, and, although it is common in some river systems, this avulsion style is particularly poorly understood. The goal of this study is to define the sedimentologic and hydrodynamic conditions associated with incisional avulsions. Using combined modeling and field approaches the PIs will evaluate how characteristics such as floodplain topography, slope, ground cover, and overbank deposition control avulsion styles and test the hypothesis that incisional avulsions occur in steep fluvial systems with topographically rough, unvegetated, well-drained floodplains that lack abundant overbank suspended-sediment supply. Modeling work will be conducted with Delft3D, a physics-based numerical model that solves the equations for water flow and sediment transport, and field-data collection will focus on ancient strata where channel and floodplain characteristics can be measured for large numbers of paleoavulsion deposits.The results from this project will help improve prediction of avulsion flood hazards and will enhance understanding of the relationships between channel avulsion and floodplain erosion and deposition. Avulsion is also a primary control on the distribution of fluvial hydrocarbon, groundwater, and CO2-storage reservoirs. Better understanding of avulsion processes gained through this research will aid subsurface predictions of reservoir quality and location. Broader impacts of this work also include development of a self-paced, web-based education module about rivers and avulsions. In collaboration with the Geoscience Outreach Foundation the PIs will design a Rivers from Above curriculum comprising guided tours of rivers and avulsions using Google Earth and Google Maps. Rivers from Above will focus on river forms and patterns, river avulsion, and avulsion impacts on society. The PIs will work with the outreach offices at Penn State and Boston College to develop, pilot test, and evaluate module activities in Pittsburgh- and Boston-area schools, targeting underserved communities in each region. Finally, this proposal will also support the education and training of several graduate and undergraduate students and the early careers of two junior faculty members.

合作研究：定义冲积盆地中切口撕脱的控制河流撕脱发生在水从河流中转移出来并在周围的洪泛区上创建新的通道时。相关的洪水对居住在沿着的人们来说可能是灾难性的，但减灾是困难的，因为模型无法预测河流撕裂的时间，位置或风格。 当一条新的河道通过侵蚀而不是沉积形成时，就会发生切割撕脱，尽管它在一些河流系统中很常见，但这种撕脱方式特别缺乏了解。本研究的目的是确定与切口撕脱相关的沉积学和水动力学条件。使用组合建模和现场方法的PI将评估如何特点，如河漫滩地形，坡度，地被，和漫滩沉积控制撕脱的风格和测试的假设，即切口撕脱发生在陡峭的河流系统与地形粗糙，无植被，排水良好的河漫滩，缺乏丰富的漫滩悬浮泥沙供应。建模工作将使用Delft 3D进行，Delft 3D是一种基于物理的数值模型，可求解水流和泥沙输运方程，和字段-数据收集将集中在古地层，在那里可以测量大量古撕脱沉积物的河道和河漫滩特征。本项目的结果将有助于改善撕脱洪水灾害的预测，并将加深对河道撕脱与河漫滩侵蚀和沉积剥蚀作用也是控制河流油气、地下水和CO2储层分布的主要因素。通过这项研究更好地了解撕脱过程将有助于地下预测储层质量和位置。这项工作的更广泛影响还包括开发一个关于河流和撕脱伤的自定进度的网上教育模块。在与地球科学外展基金会的合作下，PI将设计一个河流从上面的课程，包括使用谷歌地球和谷歌地图引导河流和撕脱的图尔斯之旅。河流从上面将集中在河流的形式和模式，河流撕裂，和撕裂对社会的影响。PI将与宾夕法尼亚州立大学和波士顿学院的外联办公室合作，在匹兹堡和波士顿地区的学校开发、试点测试和评估模块活动，目标是每个地区服务不足的社区。最后，该提案还将支持几名研究生和本科生的教育和培训以及两名初级教师的早期职业生涯。