How snow modulates hydrogeomorphic change and recovery after fire

在野火之后，洪水、侵蚀和泥石流会破坏建筑物、基础设施和水道。这项研究将研究雪在短期危害和长期景观恢复中的作用。该项目以2020年科罗拉多州北部的卡梅伦峰和东部麻烦烧伤疤痕为重点，探讨了落基山脉雪区之间火灾后危害和植被恢复的方式和原因。对这些火灾的初步观察表明，与冬季积雪深厚的地区相比，在火灾发生后的头几年，积雪有限的烧伤地区有更大的洪水、侵蚀和泥石流活动。相比之下，低雪区植被恢复的速度要比高雪区快。这项研究将探索雪区之间这些差异的原因，目的是确定哪种类型的环境最容易受到火灾后的危害。研究结果将为暴洪预报提供信息，并帮助土地管理者确定缓减侵蚀和稳定河道等行动的优先次序。该项目包括通过公民科学流监测计划和向利益相关者介绍的公众宣传，它包括五年级的河流实地考察日，为K-12教师提供教育资源，以及本科生和研究生培训。研究将包括两个主要组成部分：(1)评估火灾后最初1-3年的火灾危害原因；(2)检查火灾后10年或更长时间内积雪变化及其对植被恢复的影响。危害分析将探讨三种可能导致低雪区火灾后危害更大的原因：(1)降雨强度较大；(2)更大的坡面流生成；(3)更大的坡流连通性。降雨分析将使用雨量计和网格降雨产品；地面流量分析将使用无人机图像中的溪流阶段测量和细沟网络测绘，而山坡-溪流连接指标将从激光雷达和无人机地形数据中计算出来。积雪和植被分析将包括实地和遥感两部分。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。植被调查和无人机图像将记录植被恢复速度。遥感分析将把研究结果从研究火灾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。当地实地观测和区域尺度分析相结合，将能够把特定地点的调查结果与其对更大流域的影响联系起来。该奖项由水文科学和地貌与土地利用动力学项目共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.