Collaborative Research: A field, laboratory and theoretical study of mixed bedrock-alluvial meandering rivers.

本项目的重点是河道曲折，这是地貌学中的一个标志性现象，也是河道地貌动力学的一个基本过程。其目的是促进我们对侵蚀河道曲流地貌动力学的理解，从而为各种环境下的河道曲流形成一个通用的理论框架。一个特别的重点是基岩-冲积混合河道的曲折，以及沉积物复盖物在河道侵蚀模式中的中介作用。目前正在通过实地研究、实验室实验、数值模拟和理论分析相结合的方法来研究这种过程。这项研究的新方面包括：(I)在野外和实验室中研究微观尺度的溶解弯道，作为宏观尺度磨擦弯道的替代；(Ii)发展曲流地貌动力学模型，其河道横截面不是固定的，而是根据侵蚀速率的插件本构方程演变的。曲折的溪流和河流是美国和其他地区自然景观的重要组成部分。几个世纪以来，这些河流中的许多已经被彻底修改，它们在环境中的关键作用受到了损害。近年来，随着这种环境破坏的负面影响变得明显，修复这些河流已成为一项优先事项。为了补救措施的成功，以及对曲折河流的有效评估和管理，需要对河道地貌动力学有一个透彻的了解。该项目的目的是加深这种理解，并将这些进展传递给对这一主题感兴趣的广大科学家和工程师社区。

The focus of this project is the meandering of river channels, an iconic phenomenon in geomorphology and a fundamental process of channel morphodynamics. The goal is to advance our understanding of meander morphodynamics in eroding channels enough to develop a general theoretical framework for channel meanders in a variety of environments. A particular focus is the meandering of mixed bedrock-alluvial channels and the role of sediment cover in the mediation of patterns of channel erosion. Such processes are being studied through a combination of field studies, laboratory experiments, numerical simulations and theoretical analysis. Novel aspects of the research include: (i) the study of micro-scale dissolutional meanders in the field and the laboratory as a proxy for macro-scale abrasional meanders, and (ii) the development of meander morphodynamic model whose channel cross-section is not fixed but rather evolves according to a plug-in constitutive equation for erosion rate.Meandering streams and rivers are a vital part of the natural landscape of the United States and beyond. Over the centuries, many of these rivers have been modified drastically and their crucial environmental role compromised. Remediation of these rivers has become a priority in recent years as the negative effects of such environmental damage have become clear. For remediation to succeed, and for the assessment and management of meandering rivers to be effective, a thorough understanding of channel morphodynamics is needed. The aim of this project is to deepen such understanding and to pass on these advances to the broad community of scientists and engineers interested in the topic.