Census 2020: Blocks for San Francisco Clipped to the Shoreline

<strong>A. SUMMARY</strong>
Census blocks with Pacific Ocean and San Francisco Bay water clipped out. Census blocks are the smallest geographic area for which the Bureau of the Census collects and tabulates decennial census data, are formed by streets, roads, railroads, streams and other bodies of water, other visible physical and cultural features, and the legal boundaries shown on Census Bureau maps. More information on the census tracts can be found <u><a href="https://www.census.gov/newsroom/blogs/random-samplings/2011/07/what-are-census-blocks.html">here</a></u>.

<strong>B. HOW THE DATASET IS CREATED</strong>
The boundaries are uploaded from TIGER/Line shapefiles provided by the <u><a href="https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2021&layergroup=Blocks+%282020%29">U.S. Census Bureau</a></u> and clipped using the <u><a href="https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2021&layergroup=Water">water boundaries</a></u> provided by the U.S. Census Bureau.

<strong>C. UPDATE PROCESS</strong>
This dataset is static. Changes to the census blocks are tracked in multiple datasets. See here for <u><a href="https://data.sfgov.org/d/94d7-d6m6">2000</a></u> and <u><a href="https://data.sfgov.org/d/2uzy-uv2r">2010</a></u> census tract boundaries.

<strong>D. HOW TO USE THIS DATASET</strong>
This boundary file can be joined to other census datasets on GEOID. Column descriptions can be found on in the <u><a href="https://www.census.gov/programs-surveys/geography/technical-documentation/complete-technical-documentation/tiger-geo-line.2020.html">technical documentation</a></u> included on the census.gov website

<strong>E. RELATED DATASETS</strong>
<u><a href="https://data.sfgov.org/d/tmph-tgz9">Census 2020: Census Tracts for San Francisco</a></u>
<u><a href="https://data.sfgov.org/d/sevw-6tgi">Analysis Neighborhoods - 2020 census tracts assigned to neighborhoods</a></u>
<u><a href="https://data.sfgov.org/d/p2fw-hsrv">Census 2020: Blocks for San Francisco</a></u>
<u><a href="https://data.sfgov.org/d/24e8-pd2q">Census 2020: Blocks Groups for San Francisco</a></u>
<u><a href="https://data.sfgov.org/d/6rf8-dnst">Census 2020: Blocks Groups for San Francisco Clipped to SF Shoreline</a></u>

<strong>一、概要</strong>

删除了太平洋和大旧金山湾水域的普查区块。普查区块是美国人口普查局收集和编制十年人口普查数据的最低地理单元，由街道、道路、铁路、溪流以及其他可见的物理和文化特征以及人口普查局地图上显示的法律边界组成。有关普查区块的更多信息，请参阅<a href="https://www.census.gov/newsroom/blogs/random-samplings/2011/07/what-are-census-blocks.html">此处</a>。

<strong>二、数据集创建方式</strong>

边界数据从美国人口普查局提供的TIGER/Line形状文件上传，并使用美国人口普查局提供的<a href="https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2021&layergroup=Water">水域边界</a>进行裁剪。

<strong>三、更新流程</strong>

本数据集为静态数据集。普查区块的变更在其他多个数据集中进行跟踪。有关2000年和2010年普查区边界的更多信息，请参阅<a href="https://data.sfgov.org/d/94d7-d6m6">此处</a>和<a href="https://data.sfgov.org/d/2uzy-uv2r">此处</a>。

<strong>四、如何使用此数据集</strong>

此边界文件可以与基于GEOID的其他普查数据集进行连接。列描述可以在人口普查局网站上的<a href="https://www.census.gov/programs-surveys/geography/technical-documentation/complete-technical-documentation/tiger-geo-line.2020.html">技术文档</a>中找到。

<strong>五、相关数据集</strong>

<a href="https://data.sfgov.org/d/tmph-tgz9">Census 2020: San Francisco的普查区</a>
<a href="https://data.sfgov.org/d/sevw-6tgi">分析邻里 - 2020年普查区分配给邻里</a>
<a href="https://data.sfgov.org/d/p2fw-hsrv">Census 2020: San Francisco的区块</a>
<a href="https://data.sfgov.org/d/24e8-pd2q">Census 2020: San Francisco的区块组</a>
<a href="https://data.sfgov.org/d/6rf8-dnst">Census 2020: 裁剪至SF海岸线的San Francisco区块组</a>