Collaborative Research: Climatic and geologic controls on the threshold conditions for bedrock single- and multi-thread channels

河流雕刻山谷，运输营养物和沉积物，并在山区创造栖息地。在山区特别重要的是基岩河，其河岸和河床是坚硬的岩石，而不是砾石或沙子。基岩河流可以包含在一个单一的河道中，也可以分支成多个被称为辫状或吻合的河道。河流是否有一个或多个渠道影响山坡-洪泛平原-河流的连接，这对养分转移和栖息地至关重要。该项目的目的是了解为什么基岩河流根据气候和构造条件形成一个或多个通道。这项研究将有助于了解基岩河流在哪里有更大的栖息地潜力，并可以为山区河流的保护工作提供信息。该项目将通过指导研究将高性能计算引入一所小型本科学院，并将通过洪水和侵蚀危害活动支持扩展到科罗拉多州k -5年级的学校。本研究通过开发一个新的数值模型来测试导致单螺纹基岩通道稳定性的气候、岩性和岩石隆起条件，该模型明确考虑了蜿蜒过程中可变的通道宽度。该数值模型是利用俄勒冈州史密斯河（Smith River）的宇宙生成放射性核素和光激发发光得出的河道迁移和侵蚀速率，以及基岩河道条件的全球数据集进行校准的。预期结果将区分适合丰富栖息地发育和营养/沉积物连通性的地质和气候条件，并帮助科学家了解基岩河流及其阶地中编码的过去条件。开发的模型将通过美国国家科学基金会支持的社区表面动力学建模系统（CSDMS）公开共享。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。

Rivers carve valleys, transport nutrients and sediment, and create habitat in mountainous regions. Of particular importance in mountain regions are bedrock rivers, whose banks and bed are solid rock rather than gravel or sand. Bedrock rivers can be contained to a single channel or can branch into multiple channels known as braided or anastomosing. Whether the river has one or multiple channels impacts the hillslope-to-floodplain-to-river connection that is crucial to nutrient transfer and habitat. The goal of this project is to understand why bedrock rivers form one or multiple channels based on the climate and tectonic conditions. The research will help understand where bedrock rivers have greater potential for habitat and can inform conservation efforts in mountain rivers. The project will introduce high performance computing to a small undergraduate college through mentored research and will support outreach to Colorado K-5th grade schools through a flooding and erosion hazards activity.This research tests the climatic, lithologic, and rock uplift conditions that lead to single-thread bedrock channel stability through the development of a new numerical model that explicitly considers variable channel width during meandering. The numerical model is calibrated using cosmogenic radionuclide and optically stimulated luminescence derived rates of channel migration and erosion in the Smith River, Oregon, as well as a global dataset of bedrock channel conditions. Expected results will distinguish the geologic and climatic conditions suitable for rich habitat development and nutrient/sediment connectivity, and help scientists understand the past conditions encoded in bedrock rivers and their terraces. The developed model will be publicly shared through the NSF-supported Community Surface Dynamics Modeling System (CSDMS).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.