We’ve added the new urban areas to the Geocorr 2022 application this month.
There are two new options in Geocorr for source or target geographies. Urban areas are the complete areas with Census Bureau codes; for example, the Columbia, MO urban area with UA code 18937. Urban/rural portion uses a binary designation (“U” or “R”) for each block to calculate the fraction of urban and rural population for any other geography.
There are significant changes to the urban/rural classifications for the 2020 Census. One major change is that we no longer have two different types of urban area. Previously, there were urbanized areas and urban clusters (collective called urban areas), but now there are only urban areas of a single type. In addition, the method for defining these areas is much more complex than before. The short version of the new definition, from the Bureau’s Urban and Rural page, is:
For the 2020 Census, an urban area will comprise a densely settled core of census blocks that meet minimum housing unit density and/or population density requirements. This includes adjacent territory containing non-residential urban land uses. To qualify as an urban area, the territory identified according to criteria must encompass at least 2,000 housing units or a population of at least 5,000.
Among other factors, the longer definition includes:
Initial criteria for blocks: >= 425 dwelling units/ square mile, or substantial impervious surface >= 20%, or group quarters facility and >= 500 population/square mile.
Candidate blocks are then assembled into urban areas:
Start with an initial contiguous core area with >= 500 dwelling units.
Add nearby noncontiguous urban blocks: any number of “hops” <= 0.5 mile over land area, and up to one “jump” of 0.51 – 1.5 miles over land area.
Combined urban area must have at least 5,000 population or at least 2,000 housing units.
Enclaves or surrounded areas are added (or removed), and additional qualifying criteria (airports, indentations, high-employment areas, impervious areas) are applied.
We’ve added current American Indian / Alaska Native / Native Hawaiian areas. These areas include American Indian reservations (state and federal), off-reservation trust lands, Hawaiian home lands (HHLs), joint-use areas, Oklahoma tribal statistical areas (OTSAs), Alaska native village statistical areas (ANVSAs), state designated tribal statistical areas (SDTSAs), and tribal designated statistical areas (TDSAs). Alaska Native Regional Corporations [ANRCs] and tribal subdivisions are not included in MABLE/Geocorr.
The Bureau released block equivalency files for 118th congressional districts and 2022 state legislative districts this month — two months early! — so we’ve replaced the “provisional” CD/SLDs with these new “official” ones.
The next major addition to Geocorr will be the new urban/rural classifications, expected December 2022 or January 2023. There are significant changes to the urban/rural classifications for the 2020 Census — we’ll post more about that later, but if you’re interested, the Bureau’s Urban and Rural page has more detail.
Please report any errors to Glenn Rice (email@example.com).
We’ve added several new geography types to the Geocorr 2022 application. The new 2020-vintage PUMAs (public use microsample area), released just a few weeks ago, are now available. By request, we’ve also restored the 2010-vintage PUMAs to facilitate crosswalks.
Because the new PUMAs are based on the 2020 census but were released in 2022, we’re interchangeably calling them 2020 and 2022 PUMAs. (This is the same way we handled the 2010/2012 PUMAs.)
Many of our users have been asking when the new, post-Census-2020 Congressional districts would be available in Geocorr. The short answer is that 118th CDs are now included in Geocorr 2022, along with current state legislative districts.
A somewhat longer answer is that the U.S. Census Bureau has not yet released shapefiles or block lists for building 118th CDs or current SLDLs or SLDUs from 2020 tabulation blocks — and is not planning to do so for several months yet.
The Bureau’s Redistricting Data Office (RDO) intends to publish block equivalency files for the 118th Congress and for the 2022 state legislative districts, but not until December of 2022 at the earliest. And, the Bureau’s Geography division will not be releasing block allocation files for the same areas at all. However, the new areas will be published as shapefiles in the cartographic boundary files collection around April or May of 2023. They may also be released with the 2022 TIGER/Line shapefiles, generally around October.
Because of this lack of availability, we obtained new CD and state legislative boundary shapefiles from The American Redistricting Project, merged them, and ran intersections against 2020 TIGER/Line block shapefiles to determine how every block fits into the new districts. This was a tedious process, especially since the block and district shapefiles didn’t line up exactly, but we now have enough data to use for correlations.
With all that said, the new legislative geographies in Geocorr 2022 should be considered provisional until such time as they can be verified via official Census Bureau block equivalency files or shapefiles.
Of lesser interest (mainly for our Missouri users), Geocorr 2022 now also includes the most recent MO library districts.
In addition, for the convenience of our GIS users, we’ve added national shapefiles for the 2022-vintage congressional districts (118th Congress) and state upper- and lower-chamber legislative districts. These were compiled from individual state shapefiles downloaded from the American Redistricting Project. We have attempted to clean and normalize the attribute tables. Please note that these are not official Census Bureau shapefiles.
We’re happy to announce a new version of Geocorr based on 2020 decennial census geographies. Thank you for your patience!
Currently, Geocorr 2022 comprises the following geographies for all states, DC, and PR (where applicable):
nation (aka “Entire universe”)
minor civil divisions (MCDs; includes townships and other county subdivisions)
places (towns, villages, cities, etc.) and census-designated places (CDPs)
core-based statistical areas (CBSAs; includes metropolitan and micropolitan statistical areas)
upper- and lower-chamber state legislative districts
Congressional districts (116th Congress)
ZCTAs (ZIP codes)
NECTAs and NECTA divisions
elementary, secondary, and unified school districts
“best” school districts and types
county and place size categories
hospital service areas and referral regions
In addition, Geocorr 2022 includes the following regions for the state of Missouri only:
Regional Planning Commissions
University of Missouri Extension regions
MO Dept. of Economic Development (MERIC) regions
MO Dept. of Transportation districts
MO Area Agencies on Aging
MO BRFSS regions
We’ll add other geography types as they become available.
Longtime users of the Geocorr applications may notice a few other changes. Geocorr 2022 does not include the concentric ring pseudo-geocode options, nor the bounding box filter option. Our server logs indicated that these options were rarely used, and in a couple of instances were not actually functional. The HTML (web page) report option is now unchecked by default. The report output is the most resource- and time-intensive block of Geocorr’s code, and frequently causes program timeouts when very long reports (e.g., those using blocks) are requested.
Although Geocorr 2022 has been thoroughly tested, it should be considered a “beta” version for the moment. Please report any errors to Glenn Rice (firstname.lastname@example.org).
The U.S. Census Bureau’s Census Academy recently released a short video in its “Data Gems” series providing a brief overview about using MCDC’s Geocorr tool to create geographical correspondences. “Whether you are looking for estimates for the nation or a population count for your city block, geography is a critical element to using and accessing Census data. The State Data Center in Missouri [MCDC] developed a great resource to help us work with Census Bureau’s geographies. In this Data Gem, you will learn how to use the Geocorr to identify the geographies that make up your area.”
The Census Academy is the Bureau’s virtual hub for learning data skills, including visualization, population and housing tools, geography, and other topics. The Data Gems are a series of short “how-to” videos for data users looking to quickly enhance census data knowledge.