CAREER:Quantifying the response of rivers and floodplains to changes in climate and land use

深入了解河流如何应对气候和土地利用的变化，对于减少洪水的影响，设计和维护诸如取水口和桥梁等结构，保护和恢复河流生态系统以及管理一般水资源至关重要。这项研究的目的是量化河道和毗邻的洪泛平原对气候和土地利用的自然和人为变化的反应。该项目的教育方面设计了正式的学习活动（在刚果国家公园的实地工作，教育实验装置的设计和建造，以及在课程中引入新的本科水平的可持续河流工程实践课程），以建立一个使用协作学习教学法的教育环境，让学生学习如何在多样化，跨学科和国际团体中工作。这些教育方面的目标是培养下一代工程师解决与水资源管理相关的科学和专业问题。非正式的学习活动，如为刚果国家公园创建互动数字平台和为高中生举办夏令营，将使公众了解人类和气候变化对他们所处环境的影响。该研究的主要科学目标是提高对河流形态动力学的认识，并能够定量预测在野外观察到的河道几何形状和模式的变化。在几十到几百公里的空间尺度和几十到几百年的时间尺度上，河床物质（沙或砾石）的运输模式和河流与河漫滩之间的泥沙交换是控制河流形态动力学的关键过程。这一假设将通过实验室实验进行验证，以深入了解沉积物粒度对河道形态的作用，建立数学模型，为河流形态动力学提供基于物理的定量工具，并进行实地考察，以表征自18世纪以来一直响应水文和土地利用变化的美国刚果河国家公园的刚果河河段河道几何形状的年度变化。还将考虑受到人类引起的土地利用变化影响的其他场址。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。

A thorough understanding of how rivers respond to changes in climate and land use is fundamental to decrease impact from flooding, to design and maintain structures such as water intakes and bridges, to protect and restore river ecosystems, and to manage water resources in general. This research is specifically designed to quantify how river channels and the adjoining floodplains respond to natural and anthropogenic changes in climate and land use. Educational aspects of this project are designed with formal learning activities (field work at the Congaree National Park, design and construction of experimental installations for education, and the introduction of a new undergraduate level course on sustainable river engineering practices into the curriculum) to build an educational environment using collaborative learning pedagogy in which students learn how to work in a diverse, interdisciplinary, and international group. These education aspects are targeted to prepare the next generation of engineers to tackle scientific and professional problems associated with water resources management. Informal learning activities, such as the creation of an interactive digital platform for the Congaree National Park and summer camps for high school students, will inform the general public on the effects that humans and a changing climate can have on the environment in which they live in. The main scientific objective of the research is to advance knowledge on river morphodynamics, and enable quantitative prediction of changes in channel geometry and pattern observed in the field. It is hypothesized that the mode of bed material (sand or gravel) transport and the exchange of sediment between the river and the floodplain are key processes controlling river morphodynamics at spatial scales ranging from tens to hundreds of kilometers and at temporal scales ranging from a few decades to several centuries. This hypothesis will be tested with laboratory experiments to gain insight into the role of sediment grain size on channel morphology, mathematical modeling to provide physics-based quantitative tools on river morphodynamics, and fieldwork to characterize the annual variability of channel geometry on a reach of the Congaree River in the Congaree River National Park, USA, that has been responding to changes in hydrology and land use since the 1700s. Additional field sites that are being affected by human-induced changes in land use will also be considered.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.