Terrestrial Condition Assessment (TCA) Alaska Uncharacteristic Fire Severity Moderate (Image Service)

Direct Download (Raster Data Gateway) Objective: The TCA Uncharacteristic Disturbance Indicator identifies locations that have had recent catastrophic disturbance including uncharacteristically severe wildfires resulting in needs for reforestation, revegetation or other restoration work.Data: The LANDFIRE Historical Percent of Mixed Severity raster dataset for Alaska (AK_120_PMS) was combined with the Monitoring Trends in Burn Severity (MTBS) data (1984-most recent) and Composite Burn Index (Parks et al. 2018) data for the year prior to the assessment year derived from NIFC Fire Perimeters (>1000 ac) to identify areas that have experienced unnaturally severe wildfires in the recent past, since 1984. There is a 2-year lag between the most recent MTBS data and the TCA Assessment year (i.e. in the 2024 TCA Assessment, available MTBS data were from 1984-2022). To reduce this lag to 1 year, we compute the Composite Burn Index (CBI) for the year prior to the current assessment year using fire perimeters from National Interagency Fire Center (NIFC) with methods adapted from Parks et al. 2019. The CBI methods were added for the 2021 assessment. The “Moderate severity” metric (layer) represents areas mapped with a dominant condition of mixed severity fire (based on PMS) but had a high severity MTBS fire in that location. Data Format: Raster data are binary: (1) “unnaturally severe fire” or (0) otherSpatial Resolution: 30mSource data: MTBS fire severity, expected fire severity , CBI methods, National Interagency Fire Center Perimeters (for CBI)Additional Resources:Details on Method Changes and Source Data VersionsOverview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour PresentationExplore the results of the most recent assessment: TCA Interactive Data ViewerLearn more about the TCA KPI: TCA Dashboard*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access RequestThis record was taken from the USDA Enterprise Data Inventory that feeds into the https://data.gov catalog. Data for this record includes the following resources: ISO-19139 metadata ArcGIS Hub Dataset ArcGIS GeoService For complete information, please visit https://data.gov.直接下载（栅格数据网关） 目标：TCA非典型扰动指标（TCA Uncharacteristic Disturbance Indicator）用于识别近期发生过灾难性扰动的区域，包括非典型高强度野火——这类区域需开展再造林、植被恢复或其他修复工作。 数据集说明：本数据集将LANDFIRE阿拉斯加混合烈度历史占比栅格数据集（AK_120_PMS），与烧伤烈度监测趋势（Monitoring Trends in Burn Severity, MTBS，1984年至今）数据，以及基于美国国家跨部门消防中心（National Interagency Fire Center, NIFC）火灾边界（过火面积≥1000英亩）提取的评估前一年份综合燃烧指数（Composite Burn Index, CBI，Parks等，2018）数据相结合，以识别1984年以来近期发生过非自然高强度野火的区域。当前MTBS数据与TCA评估年份存在2年滞后：例如在2024年TCA评估中，可用MTBS数据覆盖时段为1984-2022年。为将滞后缩短至1年，研究团队采用Parks等2019年的方法，基于NIFC火灾边界计算当前评估年份前一年的CBI值，该CBI计算方法于2021年评估中首次启用。“中度烈度”指标（图层）代表被标记为混合烈度火灾主导条件（基于PMS）但该位置同时发生过高烈度MTBS火灾的区域。 数据格式：栅格数据为二进制格式，其中(1)代表“非自然高强度野火”，(0)代表其他情况。 空间分辨率：30米。 源数据：MTBS火灾烈度数据、预期火灾烈度数据、CBI计算方法、NIFC火灾边界（用于CBI计算）。 附加资源： 1. 方法变更及源数据版本详情：陆地状况评估（Terrestrial Condition Assessment, TCA）专题站点或Landfire官方在线讲座演示材料 2. 探索最新评估结果：TCA交互式数据查看器 3. 了解更多TCA关键绩效指标（KPI）：TCA仪表板 4. 若无法正常查看仪表板，请提交Tableau查看器访问申请 本记录源自纳入https://data.gov目录的美国农业部企业数据清单。本记录包含的数据集资源如下：ISO-19139元数据、ArcGIS Hub数据集、ArcGIS地理服务。如需完整信息，请访问https://data.gov。