Department of Civil, Construction, & Environmental Engineering, 5500, Campanile Drive, San Diego, CA, USA.
J Environ Manage. 2020 Apr 15;260:109993. doi: 10.1016/j.jenvman.2019.109993. Epub 2020 Jan 21.
Wildfires are becoming more prevalent and are impacting forests, watersheds and important resources. Hydrologic and geomorphic processes following wildfires can include erosion flooding, and degraded water quality. To mitigate these secondary impacts, post-fire restoration treatments can be applied to a burned area to stabilize the land surface or promote vegetative regrowth. This research focuses on wood and straw mulch treatment implemented after the 2012 Waldo Canyon Fire in Colorado (United States) and estimates the spatial and temporal changes in annual and seasonal vegetation after a fire with respect to geomorphic factors. This study highlights the use of satellite-based remote sensing products to investigate the impacts of post-fire rehabilitation treatments on vegetation. Using Enhanced Vegetation Index as a proxy for vegetative growth, vegetation conditions are evaluated with respect to slope, slope aspect, and burn severity to understand the impact of the ground cover treatments on vegetation for five years before and after the fire (2007-2016). Sixty-three burned and untreated sites, forty-nine burned sites treated with wood mulch, and twenty-eight burned sites treated with straw mulch were analyzed. These sites were also compared to two control sites that were unburned and untreated, Hunter's Run and Fountain Creek. Generally, post-fire conditions did not return to pre-fire levels, where average vegetation levels were lower. By the end of the study, burned and untreated sites had larger vegetative levels than burned and treated sites. The vegetation levels of the burned sites were statistically different (α = 0.05) from pre-fire conditions in all areas of treatment. Burned sites treated with wood and straw recovered to 69% and 73% of pre-fire conditions, respectively. This work demonstrates the novel use of remote sensing to observe vegetation after post-fire treatment applications to augment the number of sites and length of time that can be analyzed. The observed change in vegetation conditions also contributes to furthering our understanding of the impacts of post-fire restoration, which is important for post-fire management.
野火越来越普遍，对森林、流域和重要资源造成影响。野火后的水文和地貌过程包括侵蚀、洪水和水质恶化。为了减轻这些次生影响，可以在燃烧区域应用火灾后恢复处理，以稳定地表或促进植被再生。本研究专注于美国科罗拉多州 2012 年瓦尔道峡谷火灾后的木柴和稻草覆盖处理，并估计火灾后地貌因素对年度和季节性植被的时空变化。本研究强调使用基于卫星的遥感产品来调查火灾后恢复处理对植被的影响。使用增强植被指数作为植被生长的代理，根据坡度、坡度方向和燃烧严重程度评估植被状况，以了解地面覆盖处理对火灾前后五年（2007-2016 年）植被的影响。分析了 63 个燃烧和未处理的地点、49 个用木柴覆盖处理的燃烧地点和 28 个用稻草覆盖处理的燃烧地点。这些地点还与两个未经燃烧和处理的对照地点，即亨特溪和方廷克里克进行了比较。一般来说，火灾后的条件并未恢复到火灾前的水平，平均植被水平较低。到研究结束时，燃烧和未处理的地点的植被水平高于燃烧和处理的地点。在所有处理区域，燃烧和未处理的地点的植被水平与火灾前条件在统计上有显著差异（α=0.05）。用木柴和稻草处理的燃烧地点分别恢复到火灾前条件的 69%和 73%。这项工作展示了使用遥感观察火灾后处理应用后植被的新颖方法，以增加可分析的地点数量和时间长度。观察到的植被条件变化也有助于进一步了解火灾后恢复的影响，这对火灾后管理很重要。
