How snow modulates hydrogeomorphic change and recovery after fire

野火过后，洪水、侵蚀和泥石流会破坏建筑物、基础设施和水道。这项研究将考察雪在短期危险和长期火灾恢复中所起的作用。该项目以2020年科罗拉多州北部的卡梅伦峰和东部麻烦的烧伤伤疤为重点，阐述了落基山脉雪区之间火灾后危险和植被恢复的差异以及原因。对这些火灾的初步观察表明，与冬季积雪较深的地区相比，在火灾发生后的头几年里，降雪有限的燃烧地区有更大的洪水、侵蚀和泥石流活动。相比之下，少雪地区的植被恢复要比多雪地区进行得更快。这项研究将探索雪区之间存在这些差异的原因，目的是确定哪些类型的环境最容易受到火灾后危险的影响。研究结果将为山洪预报提供信息，并帮助土地管理者确定减缓侵蚀和稳定河道等行动的优先顺序。该项目通过公民科学流监测计划和向利益攸关方演示纳入了公众宣传，其中包括五年级河流实地考察日，K-12教师的教育资源，以及本科生和研究生培训。这项研究将涉及两个主要部分：(1)评估火灾后1-3年内火灾后危险的原因；(2)研究火灾后10年或更长时间内的积雪变化及其对植被恢复的影响。危险分析将探讨导致低雪区火灾后危险增加的三个可能原因：(1)更高的降雨强度；(2)更多的陆上径流；(3)更大的山坡-溪流连通性。降雨分析将使用雨量计和网格降雨产品；陆流分析将使用来自无人机图像的河流阶段测量和细沟网络测绘，山坡-溪流连通性指标将根据激光雷达和无人机地形数据计算。雪和植被分析将包括实地和遥感部分。现场测量将比较烧毁和未烧毁地区的积雪，重点是树木烧焦深度如何影响积雪反照率。植被地块调查和无人机图像将记录植被恢复率。遥感分析将把研究结果扩展到整个南落基山脉生态区，评估火灾对无雪日期和火灾后植被恢复率的影响。结合当地实地观察和区域尺度分析，将能够将具体地点的调查结果与其对较大流域的影响联系起来。该奖项由水文科学和地形地貌与土地利用动力学项目共同资助。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。

In the aftermath of wildfires, flooding, erosion, and debris flows can damage buildings, infrastructure, and waterways. This research will examine the role that snow plays in both short-term hazards and longer-term landscape recovery from fire. Focusing on the 2020 Cameron Peak and East Troublesome burn scars in northern Colorado, the project addresses how and why post-fire hazards and vegetation recovery vary between snow zones of the Rocky Mountains. Initial observations at these fires indicate that burned areas with limited snow have greater flooding, erosion, and debris flow activity during the first few years after fire compared to locations with deep winter snowpack. In contrast, vegetation recovery has proceeded more rapidly in low snow than in high snow areas. The research will explore reasons for these differences between snow zones, with the aim to identify what types of settings are most vulnerable to post-fire hazards. Findings will inform flash flood forecasts and help land managers prioritize actions such as erosion mitigation and channel stabilization. The project incorporates public outreach through a citizen science stream monitoring program and presentations to stakeholders, and it includes a 5th grade river field day, education resources for K-12 teachers, and undergraduate and graduate student training. The research will involve two main components: (1) evaluating causes of post-fire hazards during the first 1-3 years post-fire, and (2) examining snow changes and their effects on vegetation recovery over a decade or more post-fire. The hazard analysis will examine three possible causes for greater post-fire hazards in lower snow zones: (1) higher rainfall intensity; (2) greater overland flow generation, and (3) greater hillslope-stream connectivity. Rainfall analyses will use rain gauges and gridded rainfall products; overland flow analyses will use stream stage measurements and rill network mapping from drone imagery, and hillslope-stream connectivity metrics will be computed from LiDAR and drone topographic data. The snow and vegetation analysis will incorporate both a field and a remote sensing component. Field measurements will compare snowpack in burned and unburned areas, with a focus on how tree char depth affects snow albedo. Vegetation plot surveys and drone imagery will document vegetation recovery rates. Remote sensing analyses will extend the findings beyond the study fires to the full Southern Rockies eco-region, evaluating fire effects on snow-free dates and post-fire vegetation recovery rates. The combination of local field observations and regional scale analysis will enable connecting site-specific findings to their implications for larger watersheds. This award is co-funded by the Hydrologic Sciences and Gemorphology & Land-use Dynamics programs.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.