Census Blocks (2020)

This dataset includes 2020 census blocks as delineated by the U.S. Census Bureau and made available through their TIGER/Line files. Census blocks are statistical areas bounded on all sides by visible features (e.g., streets, roads, streams, railroad tracks), and by non-visible boundaries (e.g., city or town limits, short line-of-sight extensions of streets and roads). Generally, census blocks are small in area (e.g., a block in a city). However, census blocks in suburban and rural areas may be large, irregular, and bounded by a variety of features. In remote areas, they may encompass hundreds of square miles. Blocks do not cross the boundaries of any entity for which the Census Bureau tabulates data. Census blocks are numbered uniquely within the boundaries of each state, county, and census tract with a 4-character census block number. The first character of the tabulation block number identifies the block group. A block number can only be unique by using the decennial census state, county, census tract, and block codes combined. There is no consistency in block numbers from census to census. For more information about census geographies, see https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc_Ch4.pdf .This file is for reference use only. NCTCOG and its members are not responsible for errors or inaccuracies in the file.本数据集包含由美国人口普查局（U.S. Census Bureau）划定、并通过其TIGER/Line文件对外发布的2020年人口普查区块（census blocks）。 人口普查区块是一类边界由可见地物（如街道、道路、溪流、铁轨）与非可见边界（如城市或城镇界限、街道和道路的短视线延伸范围）共同围合的统计区域。通常而言，人口普查区块的面积较小（例如城市中的街区），但郊区与农村地区的人口普查区块可能面积较大、形状不规则，且由多种地物划定边界。在偏远地区，单个区块的幅员可达数百平方英里。 人口普查区块不会跨越美国人口普查局负责统计数据的任何实体的边界。 人口普查区块会在每个州、县及普查分区（census tract）的范围内，通过4位字符的区块编号实现唯一标识。统计区块编号的首位字符用于标识区块组（block group）。仅当结合十年一次人口普查的州、县、普查分区及区块代码时，区块编号才能实现唯一标识。不同人口普查之间的区块编号并不具备一致性。 如需了解更多人口普查地理相关信息，请参阅：https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc_Ch4.pdf。 本文件仅作参考用途。NCTCOG及其成员不对本文件中的错误或不准确之处承担责任。