SAFARI 2000 REFLECTANCE OF FIRE RESIDUE, KRUGER NATIONAL PARK, DRY SEASON 2000

The goal of this study was to understand the change in reflectance caused by the action of fire and the heterogeneity of fire effects (i.e., the fraction of the observation that burned and the combustion completeness of that observation). A spectral mixture model and field and satellite observations were used to compare changes in Landsat reflectance associated with fire and combustion completeness derived from field measurements at prescribed fire sites in South Africa and to substantiate and illustrate the model findings.Fire residue samples were collected from experimental burn plots in Kruger National Park during the SAFARI 2000 Dry Season Campaign in August-September of 2000. The residues include 3 different ash types: pure white ash; black ash; and residual non-photosynthetic fuel biomass (senescent grass, twigs, leaves, and bark). The samples were analyzed in the laboratory to determine their multi-spectral reflectance using an Analytic Spectral Devices (ASD) radiometer, which measures spectral reflectance in the range 0.45-2.2 um at intervals of 0.01 um. The ASD measurements were made under diffuse illumination conditions in the spectral range of 350 nm to 2500 nm, with the ASD radiometer aligned perpendicular to the samples to simulate nadir remote sensing conditions.The data file contains reflectance measurements (fraction, 0-1) for replicate samples of 3 different ash types (white ash, black ash, and non-photosynthetic vegetation) recorded at 10 nm intervals over the wavelength spectral range of 350 nm to 2500 nm. The data are stored in a single ASCII file in comma-separate-value format (.csv).

本研究旨在明晰火灾作用下的反射率变化，以及火灾影响的异质性（即观测区域的过火占比与该区域的燃烧完全程度）。本研究采用光谱混合模型（spectral mixture model），结合野外实地观测与卫星观测数据，对比分析南非计划火烧样地中，由野外实测得到的燃烧完全程度与Landsat反射率变化的关联，并验证并阐释该模型的研究结果。
2000年8—9月的SAFARI 2000旱季科考期间，研究人员从克鲁格国家公园（Kruger National Park）的实验火烧样地中采集了火残留样本。该类样本包含3种不同的灰烬类型：纯白灰烬、黑色灰烬，以及残留的非光合燃料生物质（枯落草本、细枝、叶片与树皮）。
研究人员在实验室中使用分析光谱设备（Analytic Spectral Devices, ASD）辐射计对样本开展多光谱反射率分析：该设备可在0.45~2.2 μm波段范围内以0.01 μm的间隔测量光谱反射率。本次ASD测量在漫射照明条件下进行，波段覆盖范围为350 nm至2500 nm，且将ASD辐射计垂直对准样本，以模拟天底遥感观测场景。
本数据集包含3种灰烬类型（纯白灰烬、黑色灰烬与非光合植被）的重复样本的反射率测量值（取值为0~1的比例值），测量波段以10 nm为间隔覆盖350 nm至2500 nm的光谱范围。数据以逗号分隔值格式（.csv）存储于单个ASCII文件中。