CAREER: Quantifying the controls of wildfire, climate, and tectonics on the transition between soil-mantled and bedrock hillslopes

如果侵蚀剥离山坡土壤的速度快于补充土壤的速度，基岩山坡就会出现，导致地形更加陡峭，植被更加稀疏，径流更加鲜艳，从山坡向渠道输送泥沙的机制发生变化，放大了破坏性洪水和泥石流的影响。然而，为土壤覆盖景观开发的现有模型不太适合解释由于土壤生产和侵蚀之间不平衡的短期(例如野火)或长期(例如构造)驱动因素而出现的向基岩山坡的过渡。该项目旨在通过量化从土壤覆盖的山坡到基岩山坡的转变来解决这一知识鸿沟，这种转变是由于对山区景观中土壤生产量和土壤侵蚀的相对速度的控制不同而引起的。花岗岩景观的四项实地研究将利用基岩暴露的梯度来阐明土壤生产和侵蚀率的潜在控制。该项目将利用分辨率越来越高的激光雷达、无人机和陆基摄影测量方法，有效地绘制由野火驱动的从土壤覆盖的山坡到基岩山坡的过渡、岩石抬升速率、灯塔后退和气候/植被覆盖。对原地宇宙成因10Be、土壤和基岩化学以及土壤厚度的测量将限制土壤生产力，并确定土壤生产力、土壤风化和侵蚀率如何在这些梯度上变化。该项目的成果将用于产生与低成本独立IVR耳机系统兼容的数据丰富的身临其境虚拟现实(IVR)体验，并纳入为本科生地貌学课程开发的新实验室练习。这份职业建议书的教育部分将侧重于评估IVR和传统的基于地理信息系统的实验室练习的有效性，以吸引学生参与并交流山坡地貌和临界区科学的概念。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Where erosion strips soil from hillslopes faster than it can be replenished, bedrock hillslopes emerge, leading to steeper topography, sparser vegetation, flashier runoff, and changes to the mechanisms of sediment delivery from hillslopes to channels, amplifying the effects of destructive floods and debris flows. However, existing models developed for soil-mantled landscapes are poorly suited to explain the transition to bedrock hillslopes that emerges due to either short-term (e.g. wildfire) or long-term (e.g., tectonic) drivers of imbalance between soil production and erosion. This project aims to address this knowledge gap by quantifying the transition from soil-mantled to bedrock hillslopes that arises due to variations in the controls on the relative rates of soil production and soil erosion in mountain landscapes. Four field studies in granitic landscapes will exploit gradients in bedrock exposure to elucidate the underlying controls on soil production and erosion rates. This project will take advantage of increasingly high-resolution lidar, drone, and ground-based photogrammetry methods to efficiently map the transition from soil-mantled to bedrock hillslopes driven by wildfire, rock uplift rate, knickpoint retreat, and climate/vegetation cover. Measurements of in situ cosmogenic 10Be, soil and bedrock chemistry, and soil thickness will constrain soil production rates and establish the how soil production, soil weathering, and erosion rate vary across these gradients. Results from this project will be used to generate data-rich immersive virtual-reality (iVR) experiences compatible with low-cost self-contained iVR headset systems and incorporated into new laboratory exercises developed for an undergraduate geomorphology course. The educational component of this CAREER proposal will focus on assessing the effectiveness of iVR and traditional GIS-based laboratory exercises for engaging students and communicating concepts in hillslope geomorphology and critical zone science.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.