Loudoun County, VA, Department of Management and Financial Services
REQUIRED:<DDMMYYYY; at least YYYY">
Census Block Groups of Loudoun County, VA (2020)
vector digital data
Leesburg, VA
Loudoun County, VA
withheld
GISDBP.GPROD.CENSUS2010_BLOCKGROUPS_POLY
This GIS layer contains the geographical boundaries of the 2020 census block groups for Loudoun County, Virginia. The 2020 Census block group boundaries are used for Census Bureau statistical data tabulation purposes, including the 2020 Decennial Census and American Community Surveys. Census block groups are part of the sub-county census geography hierarchy of tracts, block groups, and blocks. The three census geographies nest to each other, forming a hierarchy of census tract, followed by block groups, and then blocks, with blocks being the smallest. A census block group is a cluster of census blocks within the same census tract that have the same first digit of their four-digit census block numbers within a census tract. For example, block group 3 within census tract 610700 is a cluster of all the blocks numbered from 3000 to 3999 in that census tract. Block groups are uniquely numbered within census tracts, with the block group's valid range being 0 to 9. Block Groups are designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions, census tracts and generally contain between 600 and 3,000 people or 240 and 1,200 housing units. This 2010 Census block group GIS layer's boundaries are based on the U.S. Census Bureau Census 2020 TIGER/Line files. The boundaries are an extract of aerial photography and cartographic information, such as roads and streams, from the Loudoun County GIS system. Census block groups are bounded on all sides by visible features, such as roads, streams, lakes, power lines, and railroad tracks, and/or by non-visible boundaries such as town and county boundaries, and short line-of-sight extensions of streets and roads.
Census block groups are used in demographic analyses of Loudoun County. Census block groups are used to gain a detailed picture of population, housing, economic, and other demographic characteristics within a given area.
Loudoun County's block groups were delineated by Loudoun County Government during the Census Bureau's Participant Statistical Areas Program for the 2010 Census. The 2010 Census block layer has been modified from the Census Bureau's Tiger line file. Users should be aware that the Census's Tiger line data is devised from a mix of national and local GIS data sets. When the Tiger line data is overlaid with Loudoun County Government's detailed GIS layers it can be determined that the Census Bureau's Tiger line boundaries in some cases are slightly off from the actual location of the physical features, natural features, and governmental units such as town boundaries that they are designated to follow. The 2010 Loudoun census block group layer was generated by Loudoun County so that the block group boundaries would overlay with the features in Loudoun County's GIS data sets that the boundary are designated to follow.
The 2010 Census block group boundaries are used for Census Bureau statistical data tabulation purposes, including the 2010 Decennial Census and American Community Surveys. The American Community Survey replaced the long form of the decennial Census. The American Community Survey data sets are released annually. The 2010 to 2019 American Community Survey one-year data sets, the 2008-2010 through 2018-2020 three-year data sets, and the 2006-2010 through 2016-2020 five-year data sets will all use the 2010 Census block group geographies for statistical tabulation purposes.
Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN (vertical datum, if applicable, NAVD88), US Survey foot units.
en
2010
publication date
None planned until 2020 Census
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39.326230
38.844263
11635727.443366
11815632.016717
6992630.694961
7166506.778835
none
boundaries
boundary
Census
American Community Survey
demographic
none
REQUIRED:<all applicable 'homegrown" Loudoun County employee derived keywords>
none
Virginia
Loudoun
County
51107
none
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user.
These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.
Loudoun County, VA, Department of Management and Financial Services
mailing and physical address
803 Sycolin Rd, Suite 104
MS 61
Leesburg
VA
20175
USA
8:30-5:00 EST, M-F
Demographer
Public Information
ESRI ArcCatalog 9.3.1.4000
Feature Class
Retention of attribute accuracy throughout the personal geodatabase or shapefile to ArcSDE geodatabase feature class coversion process was ensured by a manual or automatic QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have, on a record by record basis, identical attribution when comparing all concatenated fields to all the user-defined attribution.
Topologically clean
REQUIRED: <The completeness report should describe what layer-specific selection criteria, generalization, and definitions were used to determine what is included in the datset. Ex. Water bodies less than 1/10 of an acre are not captured, or street centerlines are captured only within road casings or right of ways of officially named streets.> Use at least following paragraph for this element
Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data.
Retention of coordinate accuracy throughout the personal geodatabase or shapefile to ArcSDE geodatabase feature class conversion process was ensured by a manual or automatic QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have the same record total, and on a record by record basis, area, perimeter, and length differential of less than +/- 0.5%.
REQUIRED: <Department that created original layer>
REQUIRED: <Date layer created, year at least>
REQUIRED: <Raster or vector digital data>
REQUIRED: <Identifictaion, not description, of decision, legislation, action, annexation, etc. that resulted in layer creation. The basis for development>
REQUIRED: <Describe development of original layer and any significant edit step to original layer. Ex. Used parcel boundaries to identify and designate agricultural districts or added new feature and codes.>
REQUIRED: <Delete last process step that states: Metadata imported>
REQUIRED: <Date of process step>
REQUIRED: <Department that developed or edited original layer, Ex. OMAGI>
REQUIRED: <Identification of position that completed development or edit, Ex. GIS Specialist>
Metadata imported.
withheld
20110602
16372800
Dataset copied.
withheld
20110603
14404900
Loudoun County
Vector
Simple
FALSE
202
TRUE
FALSE
coordinate pair
0.000256
0.000256
survey feet
D_North_American_1983_HARN
Geodetic Reference System 80
6378137.000000
298.257222
GCS_North_American_1983_HARN
NAD_1983_HARN_StatePlane_Virginia_North_FIPS_4501_Feet
Not Applicable
1.000000
Not Applicable
Explicit elevation coordinate included with horizontal coordinates
CENSUS2020_BLOCKGROUPS_POLY
REQUIRED:<"point, line or polygon"> feature class
ESRI
Feature Class
202
OBJECTID
OBJECTID
OID
4
0
0
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
SHAPE
Shape
Geometry
0
0
0
Feature geometry.
ESRI
Coordinates defining the features.
GR_FIPSSTCO
GR_FIPSSTCO
String
5
0
0
Federal Information Processing State and County Code. It is a five digit code that identifies the state and county of the census block group. The first two digits designate the state and are the state FIPS code. The last three digits designate the county and are the County FIPS code
Loudoun County
GR_TRACT2020
GR_TRACT2020
String
6
0
0
the census tract that the block group is within
Loudoun County
GR_BLOCKGROUP2020
GR_BLOCKGROUP2020
String
1
0
0
One digit number that identifies the census block group within a census tract
Loudoun County
GR_GEOID2020
GR_GEOID2020
String
19
0
0
The federal information process codes.
Loudoun County
GR_POP2020
GR_POP2020
Integer
4
0
0
population of the block group
Loudoun County
GR_HHPOP2020
GR_HHPOP2020
Integer
4
0
0
Total population minus group quarters population
Loudoun County
GR_GQPOP2020
GR_GQPOP2020
Integer
4
0
0
Total population in group quarters
Loudoun County
GR_HUNITS2020
GR_HUNITS2020
Integer
4
0
0
housing unit count for the block group
Loudoun County
GR_HHLDS2020
GR_HHLDS2020
Integer
4
0
0
households of the block group. Households are occupied housing units
Loudoun County
GR_UPD_DATE
GR_UPD_DATE
Date
8
0
0
Date feature class created or modified.
Loudoun County
GR_UPD_USER
GR_UPD_USER
SmallInteger
2
0
0
Not for public distribution. Internal User ID of editor creating or modifying feature class.
Loudoun County
Shape_Length
Shape_Length
Double
8
0
0
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
Shape_Area
Shape_Area
Double
8
0
0
Area of feature in internal units squared.
Esri
Positive real numbers that are automatically generated.
REQUIRED: <Brief definition of attribute field, list codes in Entity_and_Attribute_Detail_Citation. Use only for fields that use data dictionary or code list to define values. Not for fields with list of names, colors, etc.>
REQUIRED:<"list detailed descriptions of TYPE codes per data dictionary & proper 2-letter Prefix">
FL_TYPE: Designation of <feature> type REQUIRED: <Make sure 2 letter prefix correct for layer>
code description
---- ------------------
1 2
etc.
REQUIRED:<"list proper 2-letter Prefix> FL_UPD_SOURCE: Source that created or modified feature class
0 Undetermined
1 Legacy 2 County
3 Contract
Loudoun County, VA, Office of Mapping and Geographic Information (OMAGI)
Public Information Counter
mailing and physical address
1 Harrison Street S.E., 2nd floor
MS 65
Leesburg
VA
20175
USA
(703)771-5778
(703)771-5075
mapping@loudoun.gov
8:00-4:30 EST, M-F
Downloadable Data
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user.
GDB
ESRI Personal Geodatabase Feature Class
DVD
SHP
ESRI Shapefile
DVD
DXF
AutoCad Digital Exchange File
DVD
Loudoun County distributes spatial data in ArcGIS database or shapefile & DXF format for the cost of reproduction. Countywide spatial datasets may be purchased for $22 per DVD for up to 4.5 GB of data. There is a $100 surcharge to purchase countywide topography, and a $3 charge if the item is to be mailed. If the customer wants the data in DXF format and/or would like OMAGI to custom select specific geographic areas of the County, there is an additional $7 per 15 minute increment labor charge. Select aerial imagery is also available.
Size limit: 4.5 GB. Visit our website at: http://www.loudoun.gov/omagi/index.htm, click on "OMAGI Documents and Information." Our "Products & Services" link will lead you to order forms and lists of available data.
Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information
20110606
Metadata Specialist
Loudoun County, VA, OMAGI
mailing and physical address
1 Harrison Street SE, 2nd Floor
Leesburg
VA
20175
USA
MS 65
(703)771-5778
(703)771-5075
mapping@loudoun.gov
8:00-4:30 EST, M-F
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
This metadata reflects the source Geodatabase format and specific elements may not apply if your data is exported to SHP or DXF products. User must be aware that changes to data schema occur during data export that may not be reflected in this metadata, which represents Loudoun County's corporate geodatabase. Acknowledgement of Loudoun County would be appreciated in the use of this metadata.
http://www.esri.com/metadata/esriprof80.html
ESRI Metadata Profile
en
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20210819
12324900
FALSE
20210816
14032800
CENSUS2020_BLOCKGROUPS_POLY
002
11635727.561894
11815629.718605
6992632.821297
7166492.436947
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Projected
GCS_North_American_1983_HARN
Linear Unit: Foot_US (0.304801)
NAD_1983_HARN_StatePlane_Virginia_North_FIPS_4501_Feet
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FGDC CSDGM Metadata
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FGDC
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Version 6.2 (Build 9200) ; Esri ArcGIS 10.8.1.14362
Census Block Groups of Loudoun County, VA (2020)
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6992630.694961
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Census block groups are used in demographic analyses of Loudoun County. Census block groups are used to gain a detailed picture of population, housing, economic, and other demographic characteristics within a given area.
<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This GIS layer contains the geographical boundaries of the 2020 census block groups for Loudoun County, Virginia. The 2020 Census block group boundaries are used for Census Bureau statistical data tabulation purposes, including the 2020 Decennial Census and American Community Surveys. Census block groups are part of the sub-county census geography hierarchy of tracts, block groups, and blocks. The three census geographies nest to each other, forming a hierarchy of census tract, followed by block groups, and then blocks, with blocks being the smallest. A census block group is a cluster of census blocks within the same census tract that have the same first digit of their four-digit census block numbers within a census tract. For example, block group 3 within census tract 610700 is a cluster of all the blocks numbered from 3000 to 3999 in that census tract. Block groups are uniquely numbered within census tracts, with the block group's valid range being 0 to 9. Block Groups are designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions, census tracts and generally contain between 600 and 3,000 people or 240 and 1,200 housing units. This 2010 Census block group GIS layer's boundaries are based on the U.S. Census Bureau Census 2020 TIGER/Line files. The boundaries are an extract of aerial photography and cartographic information, such as roads and streams, from the Loudoun County GIS system. Census block groups are bounded on all sides by visible features, such as roads, streams, lakes, power lines, and railroad tracks, and/or by non-visible boundaries such as town and county boundaries, and short line-of-sight extensions of streets and roads.</SPAN></P></DIV></DIV></DIV>
boundaries
boundary
Census
American Community Survey
demographic
<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user. These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.</SPAN></P></DIV></DIV></DIV>
ISO 19115 Geographic Information - Metadata
DIS_ESRI1.0
dataset
002
withheld
Feature Class
File Geodatabase Feature Class
NAD_1983_HARN_StatePlane_Virginia_North_FIPS_4501_Feet
EPSG
8.9.3(9.0.0)
202