Science Tree Canopy Cover (TCC) Conterminous United States

The USDA Forest Service (USFS) builds two versions of percent tree canopy cover data, in order to serve needs of multiple user communities. These datasets encompass conterminous United States (CONUS), Coastal Alaska, Hawaii, and Puerto Rico and U.S. Virgin Islands (PRUSVI). The two versions of data within the v2023-5 TCC product suite include: The initial model outputs referred to as the Science data; And a modified version built for the National Land Cover Database and referred to as NLCD data. The Science data - the focus of this metadata - are the initial annual model outputs that consist of two images: percent tree canopy cover (TCC) and standard error. These data are best suited for users who will carry out their own detailed statistical and uncertainty analyses on the dataset, and place lower priority on the visual appearance of the dataset for cartographic purposes. Datasets for the years 1985 through 2023 are available. The Science data were produced using a random forest regression algorithm. TCC pixel values range from 0 to 100 percent. The value 254 represents the non-processing area mask where no cloud or cloud shadow-free data are available to produce an output, and 255 represents the background value. The Science data are accessible for multiple user communities, through multiple channels and platforms. For information on the NLCD TCC data and processing steps see the NLCD metadata. Information on the Science data and processing steps are included here. Data Download and Methods Documents: - https://data.fs.usda.gov/geodata/rastergateway/treecanopycover/美国农业部森林服务局（USDA Forest Service, USFS）开发了两个版本的树木冠层覆盖率百分比数据集，以满足多类用户群体的实际需求。这两类数据集的覆盖范围涵盖美国本土（conterminous United States, CONUS）、阿拉斯加沿海地区、夏威夷、波多黎各和美属维尔京群岛（Puerto Rico and U.S. Virgin Islands, PRUSVI）。2023-5版TCC产品套件包含两个数据版本：一是被称为科学数据的初始模型输出成果；二是专为美国国家土地覆盖数据库（National Land Cover Database, NLCD）构建的修改版数据，即NLCD数据。本元数据聚焦的科学数据为初始年度模型输出成果，包含两幅栅格影像：树木冠层覆盖率百分比（Tree Canopy Cover, TCC）数据及其标准误差数据。此类数据最适配需自主开展精细化统计与不确定性分析、且对制图用途下的数据视觉呈现优先级要求较低的用户群体。数据集涵盖1985年至2023年的年度数据。科学数据采用随机森林回归算法生成。TCC的像素值取值范围为0至100%。其中，像素值254代表非处理区域掩码，即无可用无云或无云影数据以生成输出结果的区域；像素值255代表背景值。科学数据可通过多渠道与平台面向多类用户群体开放获取。如需了解NLCD TCC数据及其处理流程，请参阅NLCD元数据文档。本元数据中已包含科学数据及其处理流程的相关信息。数据下载与方法文档：- https://data.fs.usda.gov/geodata/rastergateway/treecanopycover/