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

当蜿蜒的河流流经洪泛区时，它们最终会相互交叉，形成一部分河道。该水道段可以作为水体存在，称为牛轭湖，或者充满沉积物。考虑到这些湖泊是污染物的储存库，并提供了独特的栖息地，预测一个湖泊是否会变成牛轭的能力非常重要。在切断后的初始阶段，连接的几何形状是决定牛轭进化如何进行的决定性因素。值得注意的是，具有高角度连接处的断裂带往往会在入口积聚沉积物，从而形成牛轭状地层。为了评估初始边界几何形状决定牛轭状地层可能性的观点，研究人员将对西福克白河（美国印第安纳州）最近的边界进行全面分析。他们将采用实地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，与印第水连接营和威廉姆斯夏季科学项目的合作将为当地学生提供体验式学习机会。一旦发生曲流切断，就会与主要河道形成分叉。这种分岔的稳定性决定了它最终是否会转变为牛轭湖。如果分岔不稳定并迅速被沉积物填满，形成牛轭湖的可能性就更大。为了研究初始分叉几何形状在促进沉积堵塞和牛轭状开发中的作用，该项目将重点研究印第安纳州怀特河西叉的断裂带。各种工具，包括多波束测深、海底剖面和沉积物岩心分析，将被用来评估沉积物填充的几何形状和年代。随后，这些数据将用于形态动力学模型，模拟切断事件后分叉的演变。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几何形状如何导致沉积物加速堵塞和随后的牛轭状地层。该项目由地貌学和土地利用动力学以及促进竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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 project is jointly funded by Geomorphology and Land Use Dynamics and the Established Program to Stimulate Competitive Research (EPSCoR).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.