Wildfire Risk to Communities Conditional Risk To Potential Structures (Image Service)

The data included in this publication depict the 2024 version of components of wildfire risk for all lands in the United States that: 1) are landscape-wide (i.e., measurable at every pixel across the landscape); and 2) represent in situ risk - risk at the location where the adverse effects take place on the landscape.National wildfire hazard datasets of annual burn probability and fire intensity, generated by the USDA Forest Service, Rocky Mountain Research Station and Pyrologix LLC, form the foundation of the Wildfire Risk to Communities data. Vegetation and wildland fuels data from LANDFIRE 2020 (version 2.2.0) were used as input to two different but related geospatial fire simulation systems. Annual burn probability was produced with the USFS geospatial fire simulator (FSim) at a relatively coarse cell size of 270 meters (m). To bring the burn probability raster data down to a finer resolution more useful for assessing hazard and risk to communities, we upsampled them to the native 30 m resolution of the LANDFIRE fuel and vegetation data. In this upsampling process, we also spread values of modeled burn probability into developed areas represented in LANDFIRE fuels data as non-burnable. Burn probability rasters represent landscape conditions as of the end of 2020. Fire intensity characteristics were modeled at 30 m resolution using a process that performs a comprehensive set of FlamMap runs spanning the full range of weather-related characteristics that occur during a fire season and then integrates those runs into a variety of results based on the likelihood of those weather types occurring. Before the fire intensity modeling, the LANDFIRE 2020 data were updated to reflect fuels disturbances occurring in 2021 and 2022. As such, the fire intensity datasets represent landscape conditions as of the end of 2022. Additional methodology documentation is provided in a methods document (\Supplements\WRC_V2_Methods_Landscape-wideRisk.pdf) packaged in the data download.The specific raster datasets in this publication include:Risk to Potential Structures (RPS): A measure that integrates wildfire likelihood and intensity with generalized consequences to a home on every pixel. For every place on the landscape, it poses the hypothetical question, "What would be the relative risk to a house if one existed here?" This allows comparison of wildfire risk in places where homes already exist to places where new construction may be proposed. This dataset is referred to as Risk to Homes in the Wildfire Risk to Communities web application.Conditional Risk to Potential Structures (cRPS): The potential consequences of fire to a home at a given location, if a fire occurs there and if a home were located there. Referred to as Wildfire Consequence in the Wildfire Risk to Communities web application.Exposure Type: Exposure is the spatial coincidence of wildfire likelihood and intensity with communities. This layer delineates where homes are directly exposed to wildfire from adjacent wildland vegetation, indirectly exposed to wildfire from indirect sources such as embers and home-to-home ignition, or not exposed to wildfire due to distance from direct and indirect ignition sources.Burn Probability (BP): The annual probability of wildfire burning in a specific location. Referred to as Wildfire Likelihood in the Wildfire Risk to Communities web application.Conditional Flame Length (CFL): The mean flame length for a fire burning in the direction of maximum spread (headfire) at a given location if a fire were to occur; an average measure of wildfire intensity.Flame Length Exceedance Probability - 4 ft (FLEP4): The conditional probability that flame length at a pixel will exceed 4 feet if a fire occurs; indicates the potential for moderate to high wildfire intensity.Flame Length Exceedance Probability - 8 ft (FLEP8): the conditional probability that flame length at a pixel will exceed 8 feet if a fire occurs; indicates the potential for high wildfire intensity.Wildfire Hazard Potential (WHP): An index that quantifies the relative potential for wildfire that may be difficult to manage, used as a measure to help prioritize where fuel treatments may be needed.Additional methodology documentation is provided with the data publication download. Metadata and Downloads.Note: Pixel values in this image service have been altered from the original raster dataset due to data requirements in web services. The service is intended primarily for data visualization. Relative values and spatial patterns have been largely preserved in the service, but users are encouraged to download the source data for quantitative analysis.This 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.

本出版物所包含的数据描绘了美国所有土地2024年版的全景火灾风险组成部分，包括：1）具有景观范围的性质（即在景观的每个像素上均可测量的）；2）代表现场风险——即在景观上发生不利影响的位置的风险。美国国家火灾风险数据集，包括年度燃烧概率和火势强度，由美国农业部林业服务局、落基山研究站和Pyrologix LLC生成，构成了社区火灾风险数据的基础。LANDFIRE 2020（版本2.2.0）中的植被和野地燃料数据被用作两个不同但相关的地理空间火灾模拟系统的输入。年度燃烧概率使用美国森林服务局地理空间火灾模拟器（FSim）以相对粗略的270米（m）单元格大小生成。为了将燃烧概率栅格数据提升至更细的分辨率，以便更有效地评估灾害和风险，我们将它们上采样到LANDFIRE燃料和植被数据的原生30米分辨率。在此上采样过程中，我们还把模拟的燃烧概率值扩展到LANDFIRE燃料数据中代表的不燃区域。燃烧概率栅格数据代表了截至2020年底的景观条件。火势强度特征使用30米分辨率进行模拟，该过程执行了一整套FlamMap运行，涵盖了火灾季节中发生的所有与天气相关的特征，并将这些运行综合成多种基于这些天气类型发生可能性的结果。在火势强度模拟之前，LANDFIRE 2020数据已更新以反映2021年和2022年发生的燃料扰动。因此，火势强度数据集代表了截至2022年底的景观条件。此外，还提供了方法文档（SupplementsWRC_V2_Methods_Landscape-wideRisk.pdf），包含在数据下载包中。本出版物中的具体栅格数据集包括：

对潜在结构的风险（RPS）：一种综合火灾发生可能性和强度以及针对每个像素上房屋的一般后果的度量。对于景观上的每一个位置，它提出了一个假设性的问题：“如果这里有一所房子，那么房屋的相对风险会是什么？”这允许比较已存在房屋的地区的火灾风险与可能提出新建筑的地区。此数据集在社区火灾风险网络应用中被称作房屋火灾风险。条件风险对潜在结构（cRPS）：在给定位置发生火灾时，如果该位置有一所房屋，火灾对该房屋的可能后果。在社区火灾风险网络应用中被称作火灾后果。暴露类型：暴露是火灾发生可能性和强度与社区的时空重叠。此图层划定了房屋直接暴露于相邻野地植被引发的火灾、间接暴露于如火星和房屋间的引燃等间接来源引发的火灾，或由于距离直接和间接点火源而未暴露于火灾的区域。燃烧概率（BP）：在特定位置发生野火燃烧的年度概率。在社区火灾风险网络应用中被称作火灾发生可能性。条件火焰长度（CFL）：如果发生火灾，在给定位置沿最大蔓延方向（头火）燃烧的平均火焰长度；是野火强度的平均度量。火焰长度超过4英尺的概率（FLEP4）：如果发生火灾，像素处火焰长度超过4英尺的条件概率；指示了中等到高强度的野火潜力。火焰长度超过8英尺的概率（FLEP8）：如果发生火灾，像素处火焰长度超过8英尺的条件概率；指示了高强度的野火潜力。野火危害潜力（WHP）：一个量化难以管理的野火相对潜力的指数，用作帮助确定燃料处理可能需要的优先区域的度量。与数据出版物下载一同提供了附加的方法论文档。元数据和下载。

注意：由于网络服务的数据要求，此图像服务中的像素值已从原始栅格数据集中调整。此服务主要旨在数据可视化。相对值和空间模式在服务中得到了很大程度的保留，但建议用户下载源数据进行定量分析。此记录是从为https://data.gov目录提供数据的美国农业部企业数据目录中提取的。此记录的数据包括以下资源：ISO-19139元数据、ArcGIS Hub数据集、ArcGIS GeoService。欲获取完整信息，请访问https://data.gov。