Purpose

This initiative aims to collect foundational geospatial datasets that document the basic structure and function of major cities in the Big Ten Academic Alliance (BTAA) region. These core urban layers form a modern counterpart to historical resources like Sanborn Fire Insurance maps. The collection will be made up of temporal snapshots that can support research, planning, and preservation long into the future.

The Layers

We will collect six foundational geospatial layers:

1. Address points
2. Building footprints
3. City boundaries
4. Parks
5. Streets
6. Zoning districts

Time Periods

• Primary target: 2025 datasets (to be collected and processed by end of 2025)
• Secondary targets: Earlier versions in five-year increments (2020, 2015, 2010, 2005, 2000)
• Other years: Included opportunistically, but not prioritized

The Cities

Our initial scope includes the largest cities in each state of the BTAA region:

1. Baltimore
2. Chicago
3. Columbus
4. Des Moines
5. Detroit
6. Indianapolis
7. Milwaukee
8. Minneapolis
9. Newark
10. Omaha
11. Philadelphia
12. Portland
13. Seattle

Disclaimer

This list may change or expand in based on data availability and partner interest.

Anticipated Outcomes

• Builds on the legacy of historical fire insurance maps, which are the most accessed type of resource in our geoportal by a wide margin
• Captures foundational layers that support research in housing, planning, transportation, and environmental change
• City-produced data is often high resolution and less likely to be aggregated elsewhere
• Cities tend to have stronger civic engagement and open data policies, leading to better coverage of core layers
• Smaller geographic scope makes it easier to start and manage curation efforts
• Scoped initially as a one-time project (“2025 Urban Snapshot”), providing a clear and achievable milestone
• Helps preserve ephemeral data that may be lost due to platform changes or lack of archiving
• Creates a reusable framework for both retrospective (e.g., 2020, 2015) and future (e.g., 2030) comparison

Method of Aquisition

Most of these datasets are publicly available through municipal ArcGIS Hubs. However, our preferred approach is to obtain data directly from city data providers whenever possible.

Challenges with ArcGIS Hub downloads

• Timeouts or failed downloads for large datasets
• Exported files often lack embedded metadata
• Shapefile limitations (e.g., field truncation) and reprojection may lead to data loss

Preferred approach

1. Contact city GIS staff for original-format datasets and metadata
2. Review datasets for completeness and structural integrity
3. Clip datasets to city boundaries and normalize attributes when needed
4. Document using standardized metadata fields
5. Archive in AWS
6. Index in the BTAA geoportal