Geographic Levels

Geographic levels define the administrative boundaries used for census data. Understanding these levels is essential for effective spatial analysis.

Level System

Cesteral Intelligence uses a universal level system that works across countries. This enables consistent queries regardless of local administrative terminology.

Level Hierarchy

Benefits of Universal Levels

• Cross-country analysis: Same queries work for any country
• Consistent APIs: No need to know local administrative names
• Future-proof: Adding new countries doesn't require code changes

Country-Specific Mappings

Sweden (SWE)

About DeSO Areas:

• Demographic Statistical Areas (DeSO)
• Average size: ~0.7 km²
• Population range: 700-2,700 residents
• Designed for statistical stability

Other Countries (Coming Soon)

We're expanding coverage to include:

• Norway: Fylke → Kommune → Grunnkrets
• Denmark: Region → Kommune → Sogn
• Finland: Maakunta → Kunta → Postinumeroalue

Working with Levels

Querying by Level

Select all areas at a specific level:

Country: SWE
Level: 2
→ Returns all 290 Swedish municipalities

Querying with Parent

Find all sub-areas within a parent:

Country: SWE
Parent: 01 (Stockholm County)
Include Descendants: true
→ Returns all municipalities and DeSO areas in Stockholm County

Limiting Depth

Control how many levels down to search:

Country: SWE
Parent: 01
Include Descendants: true
Max Depth: 1
→ Returns only direct children (municipalities), not DeSO areas

Area Codes

Code Structure

Area codes uniquely identify geographic areas. The format varies by country:

Sweden:

• Level 1 (County): 2 digits (01, 14)
• Level 2 (Municipality): 4 digits (0180, 1480)
• Level 3 (DeSO): 8 characters (0180C1010)

Code Properties

Each area code has:

• Unique identifier: No duplicates within a country
• Parent reference: Links to containing area
• Path: Full hierarchy from country down

Using Area Codes

Area codes are the key for:

1. Joining data: Match your data to census data
2. Spatial aggregation: Group data by geographic area
3. Hierarchical queries: Navigate up/down the hierarchy

Geographic Boundaries

Boundary Data

Each area has an associated geometry:

• Polygon: The actual boundary shape
• Centroid: Center point of the area
• Bounding box: Rectangular extent

Coordinate System

All geometries use:

• CRS: WGS84 (EPSG:4326)
• Format: GeoJSON compatible
• Precision: Suitable for mapping

H3 Spatial Indexing

For performance, we also index areas using H3 hexagonal cells.

What is H3?

H3 is a hierarchical hexagonal grid system:

• Consistent shapes: All cells are approximately equal size
• Fast queries: Efficient spatial lookups
• Multiple resolutions: From global to neighborhood scale

H3 Resolution Reference

When to Use H3

Use H3 for:

• Fast spatial filtering
• Heatmap visualizations
• Approximate spatial joins
• Zoom-based data loading

Use precise boundaries for:

• Exact point-in-polygon tests
• Official statistics
• Distance calculations
• Legal/administrative purposes

Practical Examples

Finding Areas in a Region

To get all municipalities in Stockholm County:

Query:
  country: "SWE"
  parentArea: "01"
  level: 2

Returns: Stockholm, Huddinge, Solna, Sundbyberg, etc.

Getting Area Details

To get information about a specific area:

Query:
  country: "SWE"
  areaCode: "0180"

Returns:
  name: "Stockholm"
  level: 2
  parent: "01"
  population: 984,748
  geometry: {...}

Hierarchical Navigation

To understand where an area fits:

Area: 0180C1010 (a DeSO in Stockholm)
Path: SWE → 01 → 0180 → 0180C1010
       ↓    ↓     ↓        ↓
   Country County Municipality DeSO

Best Practices

Choosing the Right Level

Handling Boundary Changes

Administrative boundaries change over time:

• Check effective dates: Use current boundaries for current data
• Historical analysis: Note which boundaries were in effect
• Document your choices: Record which boundary version you used

Performance Considerations

• Query at the highest useful level: Don't fetch DeSO data if municipalities suffice
• Use H3 for interactive maps: Switch to precise boundaries for exports
• Cache frequently used areas: Avoid re-fetching static data

Troubleshooting

Area Code Not Found

• Verify the code format matches the expected pattern
• Check if the area still exists (may have been merged)
• Ensure you're using the correct country code

Hierarchy Mismatch

• Confirm parent-child relationships are correct
• Check if boundary changes affected the hierarchy
• Validate against official administrative lists

Geometry Issues

• Ensure your data uses WGS84 coordinates
• Check for antimeridian crossing issues
• Verify polygon orientation (exterior rings counter-clockwise)