Abstract Multispectral imagery is a widely used source of information to address post-fire ecosystem management. The aim of this study is to evaluate the ability of remotely sensed indices derived from Landsat 8 OLI/TIRS to assess initial burn severity (overall, on vegetation and on soil) in fire-prone pine forests along the Mediterranean-Transition-Oceanic climatic gradient in the Mediterranean Basin. We selected four large wildfires which affected pine forests in a climatic gradient within the Iberian Peninsula. In each wildfire we established CBI plots to obtain field values of three burn severity metrics: site, vegetation and soil burn severity. The ability of 13 spectral indices to match these three field burn severity metrics was compared and their transferability along the climatic gradient assessed using linear regression models. Specifically, we analysed the performance of 12 indices previously used for burn severity assessments (8 reflective, 2 thermal, 2 mixed) and a new reflective index (dNBR-EVI). The results showed that Landsat spectral indices have a greater ability to determine site and vegetation burn severity than soil burn severity. We found large differences in indices performances among the three different climatic regions, since most indices performed better in the Mediterranean and Transition regions than in the Oceanic one. In general, the dNBR-EVI showed the best fit to site, vegetation and soil burn severity in the three regions, demonstrating broad transferability along the entire climatic gradient.

中文翻译：

---

使用 Landsat 图像沿气候梯度在易着火的松树生态系统中燃烧严重程度指标

摘要 多光谱图像是解决火灾后生态系统管理问题的广泛使用的信息来源。本研究的目的是评估源自 Landsat 8 OLI/TIRS 的遥感指数评估地中海-过渡-海洋气候梯度沿线易火松林的初始燃烧严重程度（整体、植被和土壤）的能力在地中海盆地。我们选择了影响伊比利亚半岛气候梯度中的松树林的四场大型野火。在每场野火中，我们都建立了 CBI 图以获得三个烧伤严重程度指标的现场值：场地、植被和土壤烧伤严重程度。比较了 13 个光谱指数匹配这三个现场烧伤严重程度指标的能力，并使用线性回归模型评估了它们沿气候梯度的可转移性。具体而言，我们分析了先前用于烧伤严重程度评估的 12 个指数（8 个反射指数、2 个热指数、2 个混合指数）和一个新的反射指数 (dNBR-EVI) 的性能。结果表明，Landsat 光谱指数比土壤燃烧严重程度更能确定场地和植被燃烧严重程度。我们发现三个不同气候区域的指数表现存在很大差异，因为大多数指数在地中海和过渡地区的表现优于大洋洲。总体而言，dNBR-EVI 显示出最适合这三个区域的场地、植被和土壤燃烧严重程度，表明沿整个气候梯度具有广泛的可转移性。2 混合）和新的反射指数 (dNBR-EVI)。结果表明，Landsat 光谱指数比土壤燃烧严重程度更能确定场地和植被燃烧严重程度。我们发现三个不同气候区域的指数表现存在很大差异，因为大多数指数在地中海和过渡地区的表现优于大洋洲。总体而言，dNBR-EVI 显示出最适合这三个区域的场地、植被和土壤燃烧严重程度，表明沿整个气候梯度具有广泛的可转移性。2 混合）和新的反射指数 (dNBR-EVI)。结果表明，Landsat 光谱指数比土壤燃烧严重程度更能确定场地和植被燃烧严重程度。我们发现三个不同气候区域的指数表现存在很大差异，因为大多数指数在地中海和过渡地区的表现优于大洋洲。总体而言，dNBR-EVI 显示出最适合这三个区域的场地、植被和土壤燃烧严重程度，表明沿整个气候梯度具有广泛的可转移性。因为大多数指数在地中海和过渡地区的表现要好于大洋地区。总体而言，dNBR-EVI 显示出最适合这三个区域的场地、植被和土壤燃烧严重程度，表明沿整个气候梯度具有广泛的可转移性。因为大多数指数在地中海和过渡地区的表现要好于大洋地区。总体而言，dNBR-EVI 显示出最适合这三个区域的场地、植被和土壤燃烧严重程度，表明沿整个气候梯度具有广泛的可转移性。