Controls on ridgeline profile morphology

山体滑坡、泥石流和河水泛滥等自然灾害威胁着生命和基础设施。地质学家和地质工程师的工作是确定容易发生自然灾害的地区，并预测灾害何时发生，从而改善公共安全。然而，这项工作需要对景观如何侵蚀和演变有一个基于物理学的理解。地质学家花了世纪的时间研究河流和山坡的侵蚀，但令人惊讶的是，有一个地形特征存在于所有景观中，迄今几乎没有研究。这些目前尚未描述的地形特征是山脊线-沿着沿着分隔两个相邻流域的地形分水岭的高程剖面。目前对山脊线是如何形成和侵蚀的缺乏了解，限制了对景观地貌分布的预测（即，地形的陡度如何变化），这是预测滑坡、泥石流发生、河流沉积物通量等的关键。这个建议试图了解设定山脊线形状的过程。实现这一目标将通过提高我们对景观如何形成的理解来推进基础科学，也可以改善对自然灾害的预测。除了这些好处之外，该项目还包括对未来的中学教师进行基础地球科学方面的培训。了解地球科学可以帮助学生了解和理解气候变化等社会威胁。许多中学教师缺乏地球科学培训，为未来的教师提供这种培训可以提高未来学生的地球科学教育质量。具体来说，这个项目将修改和添加到现有的理论来描述山脊线的形状。这项工作将测试三个假设的控制山脊线斜率，存在的地方峰和鞍沿着山脊线，和山脊线的形式“吻”（部分山脊俯冲下来，以满足河流出口）。每一个假设将测试对自然景观和现有的实验室实验，景观在受控条件下演变的实地数据的组合。该项目的未来教师培训部分包括为期12周的专业发展课程。未来教师（从内华达州里诺大学的一个培训项目中招募）将获得美元的收入该奖项反映了NSF的法定使命，并被认为是值得支持的，通过评估使用基金会的智力价值，更广泛的影响审查标准。

Natural hazards such as landslides, debris flows, and river flooding threaten lives and infrastructure. Geologists and geological engineers work to identify areas prone to natural hazards and predict when hazards will occur, thereby improving public safety. However, this work requires a physics-based understanding of how landscapes erode and evolve. Geologists have spent over a century studying river and hillslope erosion, but, surprisingly, there is a topographic feature present in all landscapes that has seen almost no study to date. These currently undescribed topographic features are ridgelines – the elevation profile along a topographic divide separating two adjacent watersheds. The current lack of understanding of how ridgelines are shaped and eroded limits predictions of the distribution of landscape relief (i.e., how the steepness of landscapes varies), which is key to predict landsliding, debris flow occurrence, river sediment flux and more. This proposal seeks to understand the processes that set ridgeline shape. Accomplishing this will advance basic science by improving our understanding of how landscapes are formed, and can also lead to improvements in predicting natural hazards. Beyond these benefits, the project includes training for future middle school teachers in basic earth science. Understanding earth science can help students contextualize and understand societal threats such as climate change. Many middle school teachers lack earth science training; providing this training to future teachers can improve the quality of geoscience education for future students. Specifically, this project will modify and add to existing theory to describe the shape of ridgelines. The work will test three hypotheses about the controls on ridgeline slope, the presence of local peaks and saddles along ridgelines, and the form of ridgeline ‘snouts’ (the portion where the ridge dives down to meet the river outlet). Each hypothesis will be tested against a combination of field data from natural landscapes and pre-existing laboratory experiments where landscapes are evolved under controlled conditions. The future teacher training portion of the project consists of a 12-week long professional development course. Future teachers (recruited from a training program at the University of Nevada Reno) will earn $900 stipends and will be taught basic geoscience concepts appropriate for middle school teaching and have the opportunity to develop geoscience lesson plans and present these lessons in local middle schools.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.