BSF-NSF: Collaborative Research: Deciphering the role of extreme rainstorms and hydroclimatic regime on arid escarpment retreat and sub-cliff slope evolution

BSF-NSF：合作研究：解读极端暴雨和水文气候状况对干旱悬崖退缩和悬崖边坡演化的作用

• 批准号: 2100753
• 负责人: Joel Pederson
• 金额: $ 5.44万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2100753&HistoricalAwards=false
• 关键词: BSF; NSF; Collaborative; Research; Deciphering

Desert scenery often includes lines of cliffs draped with boulders and debris, presenting obstacles to hikers and highway engineers alike. Although it may not be obvious to the casual motorist, such desert cliffs, or escarpments, contain clues about the changing environment. For example, aprons of debris shed from cliffs during landslides and storms tell a story of past changes in rainfall and temperature, extending back thousands of years in the past. Until recently, it had only been possible to read that story in its broadest outlines. Today, new data and technologies are making it possible to decipher the story much more clearly. Using detailed terrain maps obtained from airborne laser surveys, together with rainfall records, new methods for dating sedimentary features, and computer simulations, this binational US-Israel project sets out to understand how rainfall shapes desert landforms over the long term, and to provide insight into how environmental changes might translate into hazards to people and adjacent infrastructure in the short term.A recent National Academy report highlighted an understanding of causes and consequences of topographic change as a top-priority research item. To this end, arid-region escarpments provide natural laboratories in which to study connections between precipitation and landforms, both because deserts minimize the confounding influence of vegetation and because their distinctive landforms are thought to reflect past changes in rainfall. This project tests the hypothesis that landforms associated with desert cliff retreat bear signatures of rainfall magnitude-frequency relationships. The project leverages three sites in the USA and Israel that span a gradient in hydroclimatic regime from hyperarid to arid, with systematically varying rainstorm properties. Analysis of high temporal resolution rainfall data (radar and gauges), lidar topography, geochronology, and field experiments in the Colorado Plateau (US) and the Negev Desert (Israel) will inform a suite of numerical experiments using a landscape evolution model. The impacts of heterogenous space-time rainstorm characteristics on escarpment retreat will be assessed, and new methods to upscale rainstorm variability to landscape evolution timescales will be developed. Numerical models and data tools for this project will be developed as new components in Landlab Toolkit, an open-source simulation software library, expanding their utility to the broader scientific community. Analyses and results from this project will also provide materials for two new learning modules for the Utah State University Native American STEM Mentorship Project, which provides gateway research experiences for freshman-level Native American students.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.

沙漠风景通常包括一排排的悬崖，上面覆盖着巨石和碎片，给徒步旅行者和公路工程师带来了障碍。虽然对于普通的驾车者来说，这可能并不明显，但这些沙漠悬崖或悬崖包含了环境变化的线索。例如，滑坡和风暴期间从悬崖上脱落的碎片围裙讲述了过去降雨和温度变化的故事，可以追溯到数千年前。直到最近，人们只能从最广泛的角度来解读这一故事。今天，新的数据和技术使我们有可能更清楚地解读这个故事。利用从机载激光勘测中获得的详细地形图，加上降雨记录，确定沉积特征年代的新方法和计算机模拟，这个美国-以色列两国项目着手了解降雨如何长期塑造沙漠地貌，并提供有关环境变化如何在短期内转化为对人类和邻近基础设施的危害的见解。将了解地形变化的原因和后果作为优先研究项目。为此，干旱地区的悬崖提供了研究降水与地形之间联系的天然实验室，这既是因为沙漠最大限度地减少了植被的混淆影响，也是因为其独特的地形被认为反映了过去降雨量的变化。这个项目测试的假设，地貌与沙漠悬崖撤退承担降雨量的频率关系的签名。该项目利用了美国和以色列的三个站点，这些站点跨越了从极端干旱到干旱的水文气候系统梯度，具有系统变化的暴雨特性。分析高时间分辨率降雨数据（雷达和仪表），激光雷达地形，地质年代学，并在科罗拉多高原（美国）和内盖夫沙漠（以色列）的实地实验将告知一套使用景观演变模型的数值实验。将评估异质时空暴雨特征对悬崖退缩的影响，并将开发新的方法来将暴雨变异性升级到景观演变的时间尺度。该项目的数值模型和数据工具将作为开放源代码模拟软件库Landlab Toolkit的新组件开发，将其效用扩大到更广泛的科学界。该项目的分析和结果还将为犹他州州立大学美国原住民STEM导师项目的两个新学习模块提供材料，该项目为新生级别的美国原住民学生提供入门研究经验。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。