How U.S. County data are structured in GEO

There is one OWL file for each U.S. state that contains the geographical regions of its counties (we do not yet have files for the counties as geopolitical organizations, although they are coming), of the form us-fl-county-geography.owl for Florida. The permanent URL to the county file is then http://purl.obolibrary.org/obo/geo/us-fl-county-geography.owl

I generated this file using Java code I wrote that uses the OWL API. It processes the the U.S. Census file of county data downloadable from the U.S. Census site. The specific file I used is in this GitHub repo here.

The OWL file includes the following for each county:

1. An OWL individual for the county itself
2. An assertion that it's a proper continuant part of the region
3. OWL individuals for it's land area and water area (qualities)
4. OWL individuals for measurements of its land and water area in square miles
5. OWL individual for the spatial region occupied by the geographical region
6. OWL individual for an interior point in that region
7. OWL individuals for latitude and longitude measurements of that point

These individuals are connected as follows:

Connection of region of county to region of its state

Connection of region of county to land area measurements.

Note that the modeling of the measurements is according to how the Ontology for Biomedical Investigations (OBI) specifies measurements.

Connection of region of county to the latitude and longitude of its interior point (centroid)

Again, longitude and latitude are measurements and modeled according to OBI.