National Land Cover Database (NLCD) Tree Canopy Cover (TCC) PR USVI (Image Service)

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 v2021-4 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 NLCD product suite includes data for years 2011, 2013, 2016, 2019 and 2021. The NCLD data are processed to remove small interannual changes from the annual TCC timeseries, and to mask TCC pixels that are known to be 0 percent TCC, non-tree agriculture, and water. A small interannual change is defined as a TCC change less than an increase or decrease of 10 percent compared to a TCC baseline value established in a prior year. The initial TCC baseline value is the mean of 2008-2010 TCC data. For each year following 2011, on a pixel-wise basis TCC values are updated to a new baseline value if an increase or decrease of 10 percent TCC occurs relative to the 2008-2010 TCC baseline value. If no increase or decrease greater than 10 percent TCC occurs relative to the 2008-2010 baseline, then the 2008-2010 TCC baseline value is caried through to the next year in the timeseries. Pixel values range from 0 to 100 percent. The non-processing area is represented by value 254, and the background is represented by the value 255. The Science and NLCD tree canopy cover data are accessible for multiple user communities, through multiple channels and platforms. For information on the Science data and processing steps see the Science metadata. Information on the NLCD data and processing steps are included here.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.

美国农业部林业服务局（USFS）构建了两种版本的树木冠层覆盖率百分比数据，以满足多个用户群体的需求。这些数据集涵盖了美国本土、阿拉斯加沿海地区、夏威夷以及波多黎各和美国维尔京群岛（PRUSVI）。在2021-4 TCC产品套件中包含的两个版本的数据分别为：科学数据，即初始模型输出；以及为全国土地覆盖数据库（NLCD）构建的修改版数据，称为NLCD数据。NLCD产品套件包括2011年、2013年、2016年、2019年和2021年的数据。NLCD数据经过处理，以消除年度树木冠层覆盖率时间序列中的小规模年际变化，并屏蔽已知为0%树木冠层覆盖率、非树木农业和水域的冠层覆盖率像素。小规模年际变化定义为与上一年建立的树木冠层覆盖率基线值相比，树木冠层覆盖率的变化小于10%。初始的树木冠层覆盖率基线值为2008-2010年树木冠层覆盖率数据的平均值。对于2011年之后的每一年，基于像素级别的树木冠层覆盖率值在相对于2008-2010年树木冠层覆盖率基线值发生10%以上的增加或减少时，将更新到一个新的基线值。如果相对于2008-2010基线值没有超过10%的增加或减少，则2008-2010年的树木冠层覆盖率基线值将延续至下一年的时间序列中。像素值范围从0%到100%。未经处理区域由值254表示，背景由值255表示。科学数据和NLCD树木冠层覆盖率数据可通过多个渠道和平台供多个用户群体访问。有关科学数据和处理步骤的信息，请参阅科学元数据。有关NLCD数据和处理步骤的信息包含在本部分。本记录来源于为https://data.gov目录提供数据的美国农业部企业数据清单。本记录的数据包括以下资源：ISO-19139元数据、ArcGIS Hub数据集、ArcGIS GeoService。如需完整信息，请访问https://data.gov。