Boundary Selection

The Boundary Selection dialog lets you choose any US state or county as your analysis region. The selected boundary is loaded as a GeoJSON polygon and used as the bounding box.

Opening the Dialog

Click Create → Boundary in the Bounding Box panel. A modal dialog appears with:

• A search box at the top
• A scrollable list of all US states and counties

Searching

Type in the search box to filter the list. The search is case-insensitive and matches on the state or county name. For example, typing orange shows Orange County (FL), Orange County (CA), etc.

Keyboard Navigation

Key	Action
↑ / ↓ Arrow keys	Move selection up or down in the list
Enter	Confirm the currently highlighted boundary
Escape	Close the dialog without selecting

Selecting a Boundary

Click any item in the list (or press Enter with keyboard navigation) to:

1. Load the boundary GeoJSON
2. Close the dialog
3. Render the boundary as the active bounding box on the map
4. Fly the camera to fit the boundary in view

Data Sources

Boundary geometry comes from the us-atlas npm package served via jsDelivr CDN:

Data	URL
US States	https://cdn.jsdelivr.net/npm/us-atlas@3.0.0/states-10m.json
US Counties	https://cdn.jsdelivr.net/npm/us-atlas@3.0.0/counties-10m.json

The topology is in TopoJSON format (10m resolution) and is converted to GeoJSON polygons client-side.

Social Vulnerability Index (SVI)

When the SVI filter is active in the analysis, county boundaries selected here are cross-referenced against the CDC/ATSDR 2022 Social Vulnerability Index dataset (SVI_2022_US_county.csv). Counties are matched by their 5-digit FIPS code.

Implementation Notes

• State/county data is fetched once and cached in usStatesData and usCountiesData variables
• The boundary dialog (#bbBoundaryDialog) is shown/hidden with CSS classes
• populateBoundaryList(searchTerm) filters and renders the list
• Selected boundary coordinates are stored in boundingBoxCoordinates[] as Cesium.Cartesian3 points for use by the analysis engine