FIA Landcover County Estimates - 2015 (Feature Layer)

This feature class represents forest area estimates (and percent sampling error) by county for the year 2015. The data was generated from the Forest Inventory Analysis (FIA) using the EVALIDator web tool (https://apps.fs.usda.gov/Evalidator/evalidator.jsp). The areas were calculated within county limits using the US Census Bureau's county spatial data (https://www.census.gov/geo/maps-data/data/cbf/cbf_counties.html). Features and attributes of the county layer were adapted to match attributes within the FIA database (FIADB) and features have been generalized by removing vertices to enhance performance. Future iterations of this dataset will be produced using refined methods and higher resolution spatial data. <a href='https://data.fs.usda.gov/geodata/edw/datasets.php?xmlKeyword=FIA+Landcover+County+Estimates' target='_blank' rel='nofollow ugc noopener noreferrer'>Metadata and Downloads</a>

本要素类代表2015年各县级行政区的森林面积估算值（及抽样误差百分比）。本数据集依托EVALIDator网页工具，基于森林资源清查分析（Forest Inventory Analysis, FIA）项目生成，工具访问地址为：https://apps.fs.usda.gov/Evalidator/evalidator.jsp。森林面积的计算以美国人口普查局提供的县级空间数据作为行政边界范围，该数据获取链接为：https://www.census.gov/geo/maps-data/data/cbf/cbf_counties.html。县级图层的要素与属性已适配森林资源清查分析数据库（FIA Database, FIADB）中的对应字段，并通过精简顶点实现要素概化，以提升运算性能。本数据集的后续迭代版本将采用更优化的方法与更高分辨率的空间数据制作。<a href='https://data.fs.usda.gov/geodata/edw/datasets.php?xmlKeyword=FIA+Landcover+County+Estimates' target='_blank' rel='nofollow ugc noopener noreferrer'>元数据与下载</a>