RAPID: Monitoring and modeling watershed-scale post-wildfire streamflow response through space and time

野火改变了水文过程，加速了侵蚀，增加了沉积物的运输速率。在美国西部，这些变化对下游基础设施和生态系统构成了相当大的风险，自然资源管理者迫切需要实用可靠的预测工具来支持野火后的管理。科罗拉多州Glenwood峡谷的Grizzly Creek野火为收集必要的现场数据以监测这些过程并开发可转移的分析工具提供了一个独特的、时间敏感的机会。该流域在研究区域的上游和下游都有活跃的长期USGS测量仪，以及高度变化的地形、土地覆盖和烧伤严重程度，使灰熊溪火灾成为捕捉同一流域内一系列野火后水文反应的理想候选者。最终，这些数据将直接支持和通知野火后的管理和恢复，每年在美国西部花费数千万美元。数据收集与美国地质勘探局火灾后泥石流灾害小组协调，以确保工作是互补的，并支持更大的水文和地貌研究工作。研究结果将通过向主要利益相关者团体（如USFS、NRCS、犹他州自然资源部、水资源保护区、水坝运营商和其他相关团体）进行介绍，传达给野火后的研究和管理社区。为该项目收集的水文野外数据将支持评估和改进野火后水文和沉积物动力学模型，并推进对水文过程的基本理解。合理的水文强迫仍然是评估野火后沉积物动力学的网络尺度建模框架的主要限制。为了填补这一空白并提高我们对流域野火后水文反应的理解，需要快速动员，以长期的流量记录和可变的流域和燃烧特征来捕捉最近被烧毁的流域的初始反应。监测点沿着烧伤严重程度梯度捕获类似的流域特征（例如，坡度、土地覆盖），并与附近未燃烧的模拟集水区配对。整个烧毁地区的降水、河流流量和山坡入渗率将随时间进行监测。这些易腐烂的数据将在一个新的分析框架内使用，以回答与野火后降雨径流响应随空间和时间变化有关的关键研究问题，从燃烧后立即开始。这项研究将有助于确定流域内被烧毁地区的空间分布和严重程度如何影响野火后的径流、分布的河流响应以及最终的沉积物通量率。这项研究将促进长期沉积物运输和储存预测，并为资源管理提供信息。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。

Wildfires alter hydrologic processes, accelerate erosion and increase sediment transport rates. In the western U.S, these changes pose considerable risks to downstream infrastructure and ecosystems, and natural resource managers urgently need practical and reliable predictive tools to support post-wildfire management. The active Grizzly Creek wildfire in Glenwood Canyon, CO, presents a unique, time-sensitive opportunity to collect necessary field data to monitor these processes and develop transferable analytical tools. The watershed has active long-term USGS gauges both up and downstream from the study area as well as highly variable topography, land cover and burn severity, making the Grizzly Creek fire an ideal candidate to capture a range of post-wildfire hydrologic responses within the same watershed. Ultimately, this data will directly support and inform post-wildfire management and restoration, which costs tens of millions of dollars across the western U.S. each year. Data collection is in coordination with the USGS Post-Fire Debris-Flow Hazards team to ensure efforts are complementary and support larger hydrologic and geomorphic research efforts. Results will be conveyed to the post-wildfire research and management community through presentations to major stakeholder groups, such as the USFS, NRCS, Utah Division of Natural Resources, water conservation districts, dam operators, and other relevant groups.Hydrologic field data collected for this project will support evaluation and improvement of post-wildfire hydrology and sediment dynamics models, as well as advances in fundamental understanding of hydrologic processes. Reasonable hydrologic forcing remains a major limitation of network-scale modeling frameworks to assess post-wildfire sediment dynamics. To fill this gap and improve our understanding of post-wildfire hydrologic response across a watershed requires rapid mobilization to capture the initial response in a recently burned watershed with long-term streamflow records and variable watershed and burn characteristics. Monitoring sites capture similar watershed characteristics (e.g., slope, land cover) along a burn severity gradient, and are paired with nearby analog unburned catchments. Precipitation, streamflow and hillslope infiltration rates will be monitored through time throughout the burned area. This perishable data will be used within a novel analytical framework to answer critical research questions related to variability in the post-wildfire rainfall-runoff response through space and time, beginning immediately following a burn. The research will help determine how the spatial distribution and severity of burned areas within a watershed impact post-wildfire runoff, distributed streamflow response and, ultimately, sediment flux rates. This research will advance long-term sediment transport and storage predictions in this and other emerging modeling efforts that inform resource management.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.