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

该项目将调查泥石流在塑造山脉方面的作用。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，每年携带大量的沉积物。然而，对它们在塑造地形中的作用知之甚少，以至于在景观演化模型中基本上被忽视了。该项目将通过一个全面的数据收集、地形分析、过程监控以及模型开发和测试计划，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，这两个领域是世界上研究碎片流动力学最好的领域之一。第一个是意大利的亚平宁山脉中部，那里第四纪断块运动速率的非常详细的数据为研究地貌对构造作用力的响应提供了无与伦比的天然实验室。第二个是俄勒冈州海岸山脉，在那里，强大的历史过程研究提供了一个丰富的数据库，用于测试和改进泥石流冲刷形成山谷的模型。在亚平宁山脉，地貌测绘和自动化过程监测将描绘流动动力学的性质，包括频率-幅度特性和河床磨损过程。对经历不同已知相对抬升速率的约200条陡峭山区河道进行数字地形分析，将产生一个关于泥石流主导河道对构造作用力的响应的大型数据库。这些数据将被用来开发，测试和完善一个一维物理为基础的模型，在不同的构造抬升速率下的泥石流侵蚀驱动的山谷长剖面演变。在俄勒冈州海岸山脉，那里已经知道了很多关于泥石流的性质和范围，研究将集中在现有的景观演变模型中开发一个泥石流模块，并测试这个模型的能力，以解释观测到的地形分布，土壤厚度和过程动态。更广泛的影响：一个成功的理论陡峭的山区源头和他们的反应构造迫使在土地使用的影响分析和地震灾害评估的应用。该项目将培训两名研究生，并使他们与国内和国际社会建立联系。通过开发开放源码图形界面和可视化工具，将使最先进的景观演变模型更易于使用。该项目的外联部分将扩大研究的影响，将项目材料，包括景观演变的最先进的可视化，作为一套指导性的调查练习，进入本科课堂。将通过与经济和种族多样化的城市学区的高中科学教师举办讲习班，试点开发和应用与标准一致的中学版本。

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.