2020 Census Block Groups for King County - Major Waterbody Features Removed

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Frequently anticipated questions:

What does this data set describe?

2020 Census Block Groups for King County - Major Waterbody Features Removed
This layer contains a geographic identifier (GEO_ID_GRP) for each block group 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.Standard block groups are clusters of blocks within the same census tract that have the same first digit of their 4-character census block number (e.g., Blocks 3001, 3002, 3003 to 3999 in census tract 1210.02 belong to block group 3). Current block groups do not always maintain these same block number to block group relationships due to boundary and feature changes that occur throughout the decade. For example, block 3001 might move due to a change in the census tract boundary. Block groups delineated for the 2020 Census generally contain 600 to 3,000 people and a block group usually covers a contiguous area. Each census tract contains one or more block groups and block groups have unique numbers within census tract. Within the standard census geographic hierarchy, block groups never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urban areas, voting districts, congressional districts, and AIANNH areas.Block groups have a valid range of zero (0) through nine (9). Block groups beginning with a zero generally are in coastal and Great Lakes water and territorial seas. Rather than extending a census tract boundary into the Great Lakes or out to the 3-mile territorial sea limit, the Census Bureau delineated some census tract boundaries along the shoreline or just offshore. Full documentation: https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc.pdf
  1. How should this data set be cited?

    County, King, 20210812, 2020 Census Block Groups for King County - Major Waterbody Features Removed: King County, King County, WA.

    Online Links:

    Other_Citation_Details: None

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -122.542001
    East_Bounding_Coordinate: -121.063188
    North_Bounding_Coordinate: 47.788361
    South_Bounding_Coordinate: 47.073373

  3. What does it look like?

    <http://www5.kingcounty.gov/sdc/DataImages/blkgrp20_shore.jpg> (JPG)
    JPG File of layer overlain on base of WA counties or local cities

  4. Does the data set describe conditions during a particular time period?

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • GT-polygon composed of chains (1544)

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet.

      Projection parameters:
      Standard_Parallel: 47.5
      Standard_Parallel: 48.73333333333333
      Longitude_of_Central_Meridian: -120.8333333333333
      Latitude_of_Projection_Origin: 47.0
      False_Easting: 1640416.666666667
      False_Northing: 0.0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.00032808333333333333
      Ordinates (y-coordinates) are specified to the nearest 0.00032808333333333333
      Planar coordinates are specified in foot_us

      The horizontal datum used is D North American 1983 HARN.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    area data table (Source: King County)

    Internal feature number. (Source: Esri)

    Sequential unique whole numbers that are automatically generated.

    Census Bureau code for a state. (Source: King County)

    Census Bureau code for a county. (Source: King County)

    Census Bureau code for a tract. (Source: King County)

    Census Bureau code for a block group. This is not unique and may appear again in other block groups in neighboring census tracts. (Source: King County)


    Unique geographic identifier for a block group. Used as the key field to join tabular data from the Census Bureau. (Source: King County)

    (Source: King County)

    Block Group 1 
    Block Group 2 
    Block Group 3 
    Block Group 4 
    Block Group 5 

    (Source: King County)

    (Source: King County)

    (Source: King County)

    (Source: King County)

    Feature geometry. (Source: Esri)

    Coordinates defining the features.

    (Source: King County)



    Entity_and_Attribute_Detail_Citation: King County

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    United States Census Bureau

  3. To whom should users address questions about the data?

    King County GIS Center
    Attn: Mary Ullrich
    GIS Specialist
    201 S Jackson St, Suite 225
    Seattle, WA 98104

    206-477-4420 (voice)

Why was the data set created?

2020 United States Census Bureau block group census geography. Converted from Census Bureau TIGER/Line shapefiles and updated to meet King County GIS standards. Major water bodies - Puget Sound, Lake Washington, Lake Sammamaish, and Lake Union have been removed.

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access Constraint: Data is available on GIS Data Portal: <http://www5.kingcounty.gov/gisdataportal/Default.aspx>
Use Constraint: King County data are made available with the understanding that they shall be used exclusively by the obtainer or his/her authorized agents. Digital products may not be reproduced or redistributed in any form or by any means without the express written authorization of King County.

  1. Who distributes the data set? (Distributor 1 of 1)

    KCGIS Center
    Attn: giscenter@kingcounty.gov
    Data Distribution
    201 S Jackson St
    Seattle, WA 98104

    206-477-4403 (voice)

  2. What's the catalog number I need to order this data set?


  3. What legal disclaimers am I supposed to read?

    Distribution Liability: King County disclaims any warranty of use of any digital product or data beyond that for which it was designed.

  4. How can I download or order the data?

Who wrote the metadata?

Last modified: 12-Aug-2021
Metadata author:
King County GIS Center
Attn: Mary Ullrich
GIS Specialist
201 S Jackson St, Suite 225
Seattle, WA 98104

206-477-4420 (voice)

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.12 on Sun Oct 17 11:41:35 2021