Collaborative Research: Unraveling the Controls on the Origin and Environmental Functioning of Oxbow Lakes

合作研究：揭示 Oxbow 湖的起源和环境功能的控制

• 批准号: 2321056
• 负责人: Doug Edmonds
• 金额: $ 24.55万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2321056&HistoricalAwards=false
• 关键词: Collaborative; Research; Unraveling; Controls; Origin

As meandering rivers move through their floodplains, they eventually intersect themselves to remove a portion of the channel. That channel segment can exist as a water body, called an oxbow lake, or become filled with sediment. The ability to predict whether a segment will transform into an oxbow holds significant importance, given that these lakes serve as repositories for pollutants and provide unique habitats. During the initial stages following cutoff, the geometry of the connection is decisive in determining how oxbow evolution plays out. Notably, cutoffs with high-angle junctions tend to accumulate sediment at the entrance, initiating oxbow formation. To evaluate the idea that the initial cutoff geometry determines the likelihood of oxbow formation, the researchers will undertake a comprehensive analysis of recent cutoffs in the West Fork White River (Indiana, USA). They will employ both field data collection and numerical modeling methodologies. Furthermore, collaboration with the Indiana Department of Environmental Management will enable estimates of pollutant storage within oxbows. Additionally, partnerships with the Indy Water Connection Camp and the Williams Summer Science Program will facilitate experiential learning opportunities for local students.Once a meander cutoff occurs, it establishes a bifurcation with the primary river channel. The stability of this bifurcation determines whether it ultimately transforms into an oxbow lake. If the bifurcation is unstable and rapidly fills with sediment, the formation of an oxbow lake becomes more probable. To investigate the role of initial bifurcation geometry in facilitating sedimentary plugging and oxbow development, the project will focus on cutoffs on the West Fork of the White River in Indiana. Various tools, including multibeam bathymetry, sub-bottom profiling, and sediment core analysis, will be employed to assess the geometry and chronology of sediment fill. Subsequently, these data will be utilized in morphodynamic models that simulate the evolution of bifurcations following a cutoff event. The presence of different bifurcation geometries will allow the researchers to model and evaluate how specific geometric configurations lead to accelerated sediment plugging and subsequent oxbow formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当蜿蜒的河流流经洪泛区时，它们最终会相交，从而去除一部分河道。这段河道可以作为一个水体存在，称为牛轭湖，也可以充满沉积物。鉴于这些湖泊作为污染物的储存库并提供独特的栖息地，预测一个部分是否会转变为牛轭的能力具有重要意义。在切断后的初始阶段，连接的几何形状决定了牛轭演化的方式。值得注意的是，高角度的交界处往往会在入口处积聚沉积物，从而形成牛轭。为了评估最初的截止几何形状决定牛轭形成的可能性的想法，研究人员将对西福克怀特河（印第安纳州，美国）最近的截止进行全面分析。他们将采用现场数据收集和数值模拟方法。此外，与印第安纳州环境管理部的合作将能够估计牛轭内的污染物储存。此外，与印地水连接营和威廉姆斯夏季科学计划的伙伴关系将促进当地学生的体验式学习机会。一旦发生弯曲切断，它建立了与主要河道的分叉。这个分叉的稳定性决定了它是否最终转变为牛轭湖。如果分叉处不稳定并迅速被沉积物填满，牛轭湖的形成就更有可能。为了研究初始分叉几何形状在促进沉积物堵塞和牛轭发展中的作用，该项目将重点关注印第安纳州怀特河西分叉的截止点。将采用各种工具，包括多波束测深、海底下剖面测量和沉积物岩心分析，评估沉积物充填的几何形状和年代。随后，这些数据将被用于形态动力学模型，模拟分叉的演变后，截止事件。不同分叉几何形状的存在将使研究人员能够模拟和评估特定的几何配置如何导致加速沉积物堵塞和随后的牛轭形成。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。