Doctoral Dissertation Research: Curvature-Migration Relations and The Planform Dynamics of Meandering Rivers

曲流河的地貌动力学一直是河流地貌学家和工程师的基本兴趣，因为这些动力学的有趣的复杂性，地貌变化在洪泛区发展和景观演变中的作用，以及横向通道迁移的经济和社会后果。 理解弯曲河流动力学的理论方法试图将横向迁移率与河道曲率和河道几何形状联系起来。 尽管基于这些方法的模型通常产生弯曲不对称性和弯曲平移模式的相当现实的预测，但基本方程尚未根据经验进行严格评估。 此外，这种模型不能再现复杂形式的弯曲发展，如双头或复合环。 本博士论文研究项目的总体目标是通过详细探索空间扩展模式的渠道曲率和局部横向迁移率之间的关系，以推进对弯曲河流横向迁移的空间结构的理解。 为了确定一组研究河段沿着蜿蜒河流的河道弯曲模式和横向迁移率，将对历史航空摄影进行基于地理信息系统的分析。 该项目将特别侧重于开发一种方法，以数学方式将自然弯曲河流的平面形状曲率描述为连续函数，而不是离散函数。 然后，曲率值将与测得的横向迁移率相关，以导出经验曲率迁移函数。 估计和理论配方将进行比较，以评估理论功能的有效性和经验功能将被用来完善曲流迁移的理论模型的预测能力。本论文的研究成果将有助于理解和预测曲流河平面动力学的空间结构，这是河流地貌学的基础研究问题。 从科学的角度来看，研究结果将评估的有效性的基本假设的理论模型的地形迁移和提高能力，以准确预测地形变化沿着蜿蜒河流。 提高预测能力从实用的角度来看是很重要的，因为蜿蜒河流的横向运动可以抹杀财产和农业用地，破坏结构，降低水质，减少水生栖息地，并降低美学质量。 这个博士论文奖还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

The planform dynamics of meandering rivers have been of fundamental interest to fluvial geomorphologists and engineers because of the intriguing complexity of these dynamics, the role of planform change in floodplain development and landscape evolution, and the economic and social consequences of lateral channel migration. Theoretical approaches to understanding the dynamics of meandering rivers have attempted to relate rates of lateral migration to channel curvature and channel geometry. Although models based on these approaches generally yield fairly realistic predictions of bend asymmetry and patterns of bend translation, the underlying equations have not been rigorously evaluated empirically. Moreover, such models are incapable of reproducing complex forms of bend development, such as double-heading or compound looping. The overall goal of this doctoral dissertation research project is to advance the understanding of the spatial structure of lateral migration of meandering rivers by exploring in detail the relationship between spatially extended patterns of channel curvature and local rates of lateral migration. To identify patterns of channel curvature and rates of lateral migration for a set of study reaches along meandering rivers, geographical information system-based (GIS-based) analysis of historical aerial photography will be conducted. The project will focus specifically on the development of a methodology for mathematically characterizing planform curvature of natural meandering rivers as a continuous, rather than discrete function. Curvature values will then be related to measured rates of lateral migration to derive empirical curvature-migration functions. Estimated and theoretical formulations will be compared to evaluate the validity of the theoretical functions and the empirical functions will be used to refine the predictive capabilities of theoretical models of meander migration. The results of this doctoral dissertation research will contribute to understanding and predicting the spatial structure of planform dynamics of meandering rivers, a fundamental research problem in fluvial geomorphology. From a scientific perspective, the results will evaluate the validity of underlying assumptions of theoretical models of planform migration and improve the capacity to accurately predict planform change along meandering rivers. Improved predictive capability is important from a practical perspective because lateral movement of meandering rivers can obliterate property and agricultural land, damage structures, reduce water quality, diminish aquatic habitat, and degrade aesthetic quality. This doctoral dissertation award will also provide support to enable a promising student to establish a strong independent research career.