RAPID: Land surface hazards under accelerating climate change: Example from 2023 Hurricane Hilary

气候对固体地球灾害的影响，如山体滑坡，泥石流，河流聚合和洪水，历史上很少受到关注，但近年来，这种影响正在扰乱社区并改变我们生活的环境。迫切需要了解新的气候状况是如何产生风暴的，这些风暴会引发前所未有的侵蚀、地面塌陷和沉积。例如，干旱环境是由长期缓慢的地貌活动形成的，其间不时发生重大事件，这些事件可以在地质瞬间改变地貌。这些事件通常由大风暴引发，也会带来一系列危害，包括洪水、山体滑坡和泥石流，这些灾害会破坏主要基础设施（例如，道路、建筑物）以及自然和文化遗产。2023年8月的飓风希拉里（英语：Hurricane Hilary）是一场四级太平洋飓风，引发了南加州前所未有的热带风暴警告，从墨西哥-美国边境延伸到洛杉矶县以北和以东地区。与大多数以狭窄、集中的带状到达该地区的冬季降水不同，飓风希拉里在加州南部的大片地区分布了大量降雨，为研究重大降水事件的广泛地貌和社会影响提供了机会。受影响最严重的地区是通常干旱的沙漠地区，这些地区的降雨量超过了通常的年降雨量，并引发了泥石流、山洪暴发和沉积物碎屑波。易腐现场数据的收集是该奖项的主要目标，以获得对泥石流观测的深入了解，从而能够对灾害级联进行长期预测。这种可以测试模型并推动对陆地表面灾害的新理解的直接观测很少，部分原因是主要的气候变化事件，尽管可能是灾难性的，但很罕见，因此很少有自然例子使用现代技术得到很好的记录。光探测和测距（LiDAR或激光扫描）和运动恢复结构（SfM）等技术可以实现变化检测和量化，从而提供以前难以理解的见解。这些数据包括详细记录土地表面变化、被侵蚀和再沉积的地面物质的特性以及对基础设施的影响。该研究将在地表灾害中心（CLaSH）的结构内进行，从而支持社区建设计划，并通过包括新的研究人员和以前未参与CLaSH的学生，吸引跨学科的研究人员参与灾害相关科学。从这项研究中产生的数据将通过开放获取存储库公开提供，使更广泛的研究界能够利用这些数据从经验上了解希拉里飓风对地质环境的影响，也是下一步的指导该奖项反映了NSF的法定使命，并已被认为值得通过使用基金会的学术价值和更广泛的影响审查标准。

The climate impact on solid earth hazards, such as landslides, debris flows, river aggregation and flooding, has historically received little attention, but in recent years, this impact is disrupting communities and altering the environment we live in. There is an urgent need to understand how new climate regimes are generating storms that unleash unprecedented episodes of erosion, ground failure and deposition. For example, arid environments are shaped by long periods of slow geomorphic activity, punctuated by major events that can transform landscapes in a geological instant. These events, often triggered by major storms, also present a range of hazards, including floods, landslides, and debris flows that can damage major infrastructure (e.g., roads, buildings) as well as natural and cultural heritage sites. The August 2023 Hurricane Hilary was a Category 4 Pacific hurricane that triggered an unprecedented tropical-storm-warning for Southern California, extending from the Mexico-US border to regions north and east of Los Angeles County. Unlike most of the wintertime precipitation that arrives in this region in narrow, concentrated bands, Hurricane Hilary distributed heavy rainfall across a wide swath of southern California, providing an opportunity to study the widespread geomorphic and societal impact of a major precipitation event. The most severely affected regions have been the normally arid desert regions, which suffered heavy rainfall in excess of typical annual totals with triggered debris flows, flash flooding and sediment debris waves. Collection of perishable field data is the main goal of this award, to gain insights into the debris flow observations that enable longer term predictions of the hazard cascade. Such direct observations that can test models and drive new understanding of land surface hazards are sparse in part because major landscape-changing events, although potentially catastrophic, are rare and thus few natural examples are well documented using modern technologies. Technologies like Light Detection and Ranging (LiDAR, or laser scanning) and Structure-from-Motion (SfM) enable change detection and quantification that provide previously elusive insights. Such data include detailed records of land surface change, the properties of ground materials that were eroded and redeposited, and impact on infrastructure. The research will be conducted within the structure of the Center for Land Surface Hazards (CLaSH), thereby supporting community building initiative and engaging researchers across disciplines in hazard-related science, by including new researchers, and students who were not previously involved in CLaSH. Data generated from this research will be made publicly available via open access repositories, enabling use by the wider research community to empirically understand the impact of Hurricane Hilary on the geologic environment, but also guide next-generation hazard cascade models that can be validated against the field data collected from this project.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.