Census Blocks are the smallest geographic area for which the Census Bureau develops polygon shapefiles and tabulates demographic data.  Census blocks are defined for each decennial census and may be updated as to block geocode and geographic extent from census to census.  In general, demographic data are tabulated at the census block level only from the decennial census.  There are more than 8 million Census  2020 census blocks covering the U.S. wall-to-wall.  This section is focused on Census 2020 census blocks using iVDA.

 

iVDA is one part of a broader VDA GIS resource framework.  See more about VDA GIS.

 

In the iVDA frame below, the arbitrary start-up view shows census blocks in the vicinity of ZIP Code 91436 in the Encino area in Los Angeles County.  The red markers show locations not immediately relevant to this application.

 

This is a demonstration application using the VDAGIS project "US1" including California blocks and will be updated in the near future.

 

Suppose you want to examine census blocks in context of a city.  In the legend panel at left,

click on the CA Blocks layer (scroll down)

click the name of the Places layer (scroll up)

key in "5000 E Montecito Ave, Fresno, CA 93702" in the searchbar and press enter.

.. the map view zooms to the city and shows a blue triangle marker at the address location.

 

click on the name on the CA Blocks layer (making it the active layer).

click the blue triangle marker and the block profile for this location shows in the lower left panel.

.. the map view zooms to the block. and shows a profile for the block in the lower left panel.

 

Try the above sequence with your own address.

 

Visual Data Analytics Web GIS
iVDA is presented below in an interactive mapping window .. watch video

Below is a static graphic example of using iVDA as described above.