Quantifying the effectiveness of shaded fuel breaks from ground-based, aerial, and spaceborne observations
Quantifying the effectiveness of shaded fuel breaks from ground-based, aerial, and spaceborne observations
复制标题
DOI：
10.1016/j.foreco.2023.121142
复制
发表时间：
2023-09
影响因子：
3.7
通讯作者：
J. Baijnath-Rodino;Alexandre Martinez;R. York;E. Foufoula‐Georgiou;A. Aghakouchak;T. Banerjee
中科院分区：
文献类型：
--
作者：
J. Baijnath-Rodino;Alexandre Martinez;R. York;E. Foufoula‐Georgiou;A. Aghakouchak;T. Banerjee
阴影燃料中断是旨在通过建立线性对齐的位置来减轻野火的治疗方法，在这些位置，野火抑制工作可以更有效地阻止野火。尽管燃料中断有可能改变火灾行为，但在暴露于野火后对其有效性的定量评估有限。此外，野火往往发生在地面车辆和传感器难以进入的复杂地形中，这给数据采集带来了挑战。然而，使用遥控飞行器（RAV），如无人驾驶飞机，作为在感兴趣的区域进行高分辨率观测的可行手段越来越受欢迎。这项研究提出了一个独特的机会，利用三个不同的观测规模的平台（原位，空中和星载）的结果，以调查燃烧严重程度的影响，在以前的阴影燃料休息，偶然遇到了2020年溪火在内华达州的塞拉利昂森林的加州，美国。为了提供火灾严重程度的直接测量，地面测量确定了烧焦和焦炭的树冠体积百分比（PCV）作为与燃料断裂边缘距离的函数。沿着沿着五条燃料中断断面，我们还利用无人机图像和数字摄影测量的可见波段，生成地理参考正射影像，并使用绿色叶指数（GLI）量化植被健康状况。我们还通过计算三角洲归一化烧伤率（dNBR）和植被健康使用归一化差异植被指数（NDVI）从哨兵2星载观测量化烧伤的严重程度。我们的研究结果表明，在燃料中断内，焦的PCV比它外面小2倍（PCV焦以2%的速度下降每3米进入燃料中断）。燃烧的严重程度是5倍以下，植被健康是约3倍以上的燃料中断相比，直接在外面。此外，与火灾前相比，火灾后植被健康在燃料中断内仅减少1倍，而在周围地区则减少5倍。结果证实，燃料中断改变了火的行为，降低了火的强度，从而证明有效地减少火灾燃烧的严重程度和保持植被健康的燃料中断。
Shaded fuel breaks are treatments that aim to mitigate wildfires by establishing linearly aligned locations where wildfire suppression efforts can be more effective at stopping wildfires. Despite the potential of fuel breaks to alter fire behavior, there have been limited quantitative assessments of their effectiveness following exposure to wildfires. In addition, wildfires often occur in complex terrains that are difficult to access with ground vehicles and sensors, posing challenges for data acquisition. However, the use of Remote-controlled Aerial Vehicles (RAVs), such as drones, is becoming increasingly popular as a viable means of conducting high-resolution observations in areas of interest. This study presents the results from a unique opportunity to utilize three distinct observation scale platforms (in-situ, aerial, and spaceborne) to investigate the burn severity impacts across a prior shaded fuel break that serendipitously encountered the 2020 Creek Fire in the Sierra Nevada forests of California, USA. To provide a direct measure of fire severity, ground-based measurements determined the percentage crown volume (PCV) of scorch and char as a function of distance from the fuel break edge. Along five transects of the fuel break, we also utilized visible bands from drone imagery and digital photogrammetry, to generate georeferenced orthophotos and quantify vegetation health using the Green Leaf Index (GLI). We also quantified burn severity by computing the Delta Normalized Burn Ratio (dNBR) and vegetation health using the Normalized Difference Vegetation Index (NDVI) from Sentinel 2 spaceborne observations. Our results indicate that within the fuel break, the PCV of char is 2 × less than it was outside of it (with PCV char declining at a rate of 2% per 3 m into the fuel break). Burn severity is 5 × less, and vegetation health is approximately 3 × greater within the fuel break compared to directly outside. Furthermore, postfire vegetation health was only 1 × less within the fuel break compared to the pre fire condition, whereas it was 5 × less in the surrounding region. The results confirm that the fuel break altered the fire behavior, reducing the fire intensity, thereby proving effective at reducing fire burn severity and preserving vegetation health within the fuel break.