Collaborative Research: The Role of Debris Flows in Shaping Mountainous Terrain

这个项目将调查泥石流在形成山脉中的作用。这是地貌学中的一个基本问题，因为泥石流显然是陡峭地形中非常重要的运输过程，每年携带大量沉积物。然而，人们对它们在地形塑造中的作用知之甚少，以至于它们在景观演化模型中基本上被忽略了。该项目将通过数据收集、地形分析、过程监控以及模型开发和测试等综合项目，帮助填补这一关键的知识空白。数据将来自两个互补的研究领域，这两个领域在研究泥石流动力学方面是世界上最好的。第一个是意大利的亚平宁山脉中部，那里有第四纪断块运动速率的非常详细的数据，为研究地形对构造强迫的反应提供了无与伦比的自然实验室。第二个是俄勒冈海岸山脉，在那里，强大的过程研究历史为测试和完善泥石流冲刷形成的山谷模型提供了丰富的数据库。在亚平宁山脉，地貌测绘和自动化过程监测将描绘出流动动力学的本质，包括频率大小特征和床磨损过程。对大约200个经历不同已知相对隆升速率的陡峭山道进行数字地形分析，将产生一个关于泥石流主导的山道对构造强迫响应的大型数据库。这些数据将用于开发、测试和完善在不同构造隆起速率下由泥石流侵蚀驱动的山谷长剖面演化的一维物理模型。在俄勒冈海岸山脉，人们对泥石流的性质和范围已经有了很多了解，研究将集中在现有景观演化模型中开发泥石流模块，并测试该模型的能力，以解释观察到的地形分布、土壤厚度和过程动力学。更广泛的影响：一个关于陡峭山源及其对构造强迫反应的成功理论已应用于土地利用影响分析和地震危害评估。该项目将培养两名研究生，并为他们提供国内和国际联系。通过开源图形界面和可视化工具的开发，一个前沿的景观演变模型将变得更容易访问。该项目的外联部分将扩大研究的影响，将项目材料，包括最先进的景观演变可视化，作为一套指导性探究练习引入本科课堂。在一个经济和种族多样化的城市学区，将通过与高中科学教师的研讨会，对中学一级标准一致的版本的开发和应用进行试点。

This project will investigate the role of debris flows in shaping mountain ranges. This is a fundamental problem in geomorphology because debris flows are clearly very important transport processes in steep terrain, carrying vast quantities of sediment every year. Yet so little is known about their role in shaping terrain that they have been essentially ignored in landscape evolution models. This project will help fill this critical knowledge gap with a comprehensive program of data collection, topographic analysis, process monitoring, and model development and testing. Data will come from two complementary study areas that are among the best in the world for studying debris-flow dynamics. The first is the central Apennines of Italy, where remarkably detailed data on rates of Quaternary fault-block motion offer an unparalleled natural laboratory for studying landscape response to tectonic forcing. The second is the Oregon Coast Range, where a strong history of process research provides a rich database for testing and refining models of valley formation by debris-flow scour. In the Apennines, geomorphic mapping and automated process monitoring will paint a picture of the nature of flow dynamics, including frequency-magnitude characteristics and processes of bed wear. Digital topographic analysis of ~200 steep mountain channels undergoing different known rates of relative uplift will yield a large database on the response of debris-flow-dominated channels to tectonic forcing. These data will be used to develop, test, and refine a 1D physically based model of valley long-profile evolution driven by debris-flow erosion under varying rates of tectonic uplift. In the Oregon Coast Range, where much is already known about the nature and extent of debris flows, research will concentrate on developing a debris-flow module in an existing landscape evolution model, and testing the ability of this model to account for observed distributions of topography, soil thickness, and process dynamics. Broader impacts: A successful theory for steep mountain headwaters and their response to tectonic forcing has applications in land-use impact analysis and seismic-hazard assessment. This project will train two graduate students and give them national and international contacts. A cutting-edge landscape evolution model will be made more accessible by the development of open-source graphical interface and visualization tools. The project's outreach component will broaden the impact of the research by bringing project materials, including state-of-the-art visualizations of landscape evolution, into the undergraduate classroom as a set of guided-inquiry exercises. Development and application of a standards-aligned version for the secondary- school level will be piloted through workshops with high school science teachers in an economically and racially diverse urban school district.