Ohio/Ohio Admin Boundary Import

Goals

Update OSM municipal boundaries in Ohio. Before starting, most boundaries were missing.

Status

Unstarted

Import Data

Background

Data source site: https://gis.dot.state.oh.us/tims/Data/Download

Data license: Public Domain

Type of license: Public Domain "Access: Public Use: User assumes risk"

ODbL Compliance verified: yes

No copyright applies per DOT email from Ian Kidner, GISP: https://i.imgur.com/YMy4EUI.png

Import Type

A one-time import done manually.

Data Preparation

Data Reduction & Simplification

The data fields are simple. Most effort is focused on geometry.

Tagging Plans

• name= [as provided by the data source]
• boundary=administrative
• admin_level= [will follow United States admin level for Ohio]
• Add the existing GNIS "populated place" nodes as role:label for town relations
  • remove gnis:*=* tags, except re-key gnis:id=* to gnis:feature_id=*
  • remove is_in=* and import_uuid=* tags
  • fix place=village to place=town or place=city
  • Not making any changes to population tags

Changeset Tags

The changeset description will be descriptive.

Source=" https://gis.dot.state.oh.us/tims/Data/Download"

Cleanup work is done with tag documentation=<link to this wiki page> and source=MEDOT

Data Transformation

Using JOSM to compare subject and reference geometries. Manually merging the data.

Data Merge Workflow

Team Approach

ZeLonewolf plans to do all the work, with Korgi1 working as QA and source of local knowledge.

Workflow

Detail the steps you'll take during the actual import.

Information to include:

• Work one municipality at a time.
• Visually compare subject to reference.
• Adjust the subject to match the reference.
• Commits will be limited to a single municipality, or a small group of nearby boundaries.

Conflation

Manual (JOSM)

Review

Korgi1 is did QA by reviewing all changesets and plans to do cleanup as needed.

Cleanup includes:

• Associating gnis nodes with boundary relations as role:label
  • Create new gnis nodes where they don't exist already for cities/towns
  • Cleaning gnis node tags (place, etc)
• Reviewing geometry
• Fixing broken relations
• Fix name errors
• Fix place=city vs place=town (https://en.wikipedia.org/wiki/List_of_cities_in_Ohio)
• Remove names from boundary ways

Current progress can be viewed: https://overpass-turbo.eu/s/19EI

See also

Discussed:

Concerns

"Townships" in Ohio require some research to find the appropriate admin_level, and may need some re-tagging after the import.

Results

• All county/city/town/township/gore (etc) are represented by administrative boundaries with correct geometry and tags
• All city/towns have a role:label that has the correct place tag and correct gnis:feature_id tag
• All city/towns have admin_level 8, everything else has admin_level 9
• The role:label of any non-city/town has a place=village (but many non-city/towns don't have a role:label)
• Townships that have a name have alt_name with their "T2 R3 Wels" style name
• Population tags were NOT improved with this work
• Wikipedia and Wikidata tags were NOT completed with this work