2020 Census Blocks for King County

For more information about this layer please see the GIS Data Catalog. This layer contains a unique geographic identifier (GEO_ID_BLK) for each block that is the key field for the data from censuses and surveys such as Decennial Census, Economic Census, American Community Survey, and the Population Estimates Program. Data from many of the Census Bureau’s surveys and censuses, are available at the Census Bureau’s public data dissemination website (https://data.census.gov/). All original TIGER/Line shapefiles and geodatabases with demographic data are available atThe TIGER/Line Shapefiles are extracts of selected geographic and cartographic information from the Census Bureau's Master Address File (MAF)/Topologically Integrated Geographic Encoding and Referencing (TIGER) Database (MTDB). The shapefiles include information for the fifty states, the District of Columbia, Puerto Rico, and the Island areas (American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the United States Virgin Islands). The shapefiles include polygon boundaries of geographic areas and features, linear features including roads and hydrography, and point features. These shapefiles do not contain any sensitive data or confidential data protected by Title 13 of the U.S.C.Census blocks are statistical areas bounded on all sides by visible features such as streets, roads, streams, and railroad tracks, and by non-visible boundaries including city, town, and county boundaries. Generally, census blocks are small in area as 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, census blocks may encompass hundreds of square miles. Census Block Numbers—Census blocks are numbered uniquely within the boundaries of each state, county, 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 (STATEFP20), county (COUNTYFP20), census tract (TRACTCE20), and block (BLOCKCE20). The entire block number is the GEO_ID_BLK. There is no consistency in block numbers from census to census.Full documentation: https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc.pdf

如需了解此图层的更多信息，请参阅GIS数据目录（GIS Data Catalog）。此图层包含每个普查区块的唯一地理标识符（GEO_ID_BLK），该标识符是十年一次人口普查（Decennial Census）、经济普查（Economic Census）、美国社区调查（American Community Survey）以及人口估计计划（Population Estimates Program）等普查与调查数据的关键字段。美国人口普查局的多项普查与调查数据均可通过该局的公开数据发布网站（https://data.census.gov/）获取。所有包含人口统计数据的原始TIGER/Line形状文件（TIGER/Line shapefiles）与地理数据库均可获取。TIGER/Line形状文件是从美国人口普查局的主地址文件（Master Address File, MAF）/拓扑集成地理编码与参考（Topologically Integrated Geographic Encoding and Referencing, TIGER）数据库（MTDB）中提取的精选地理与制图信息。此类形状文件涵盖美国50个州、哥伦比亚特区、波多黎各以及各岛屿地区（美属萨摩亚、北马里亚纳群岛联邦、关岛和美属维尔京群岛）的相关信息。形状文件包含地理区域与地物的多边形边界、道路与水文等线性地物，以及点状地物。此类形状文件未包含任何受《美国法典》第13编（Title 13 of the U.S.C.）保护的敏感数据或机密数据。普查区块（Census blocks）是指四周由街道、道路、溪流、铁路轨道等可见地物以及城市、城镇、县界等无形边界界定的统计区域。通常而言，城市中的普查区块面积较小。但郊区与农村地区的普查区块可能面积较大、形状不规则，且由多种地物界定；在偏远地区，普查区块的面积甚至可达数百平方英里。普查区块编号：普查区块在每个州、县、普查地段（census tract）范围内采用4位字符的区块编号实现唯一标识。制表区块编号的首位字符用于标识区块组。仅结合十年一次人口普查的州代码（STATEFP20）、县代码（COUNTYFP20）、普查地段代码（TRACTCE20）与区块代码（BLOCKCE20），才能确保区块编号的唯一性。完整的区块编号即为GEO_ID_BLK。不同普查周期的区块编号并不统一。完整技术文档请参阅：https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc.pdf