Location Classification Methodology

Every location is classified Urban, Peri-Urban or Rural against the UN's DEGURBA standard, using pre-computed Global Human Settlement Layer data.

Version 1.0 · DEGURBA (UN Statistical Commission, March 2020) · Updated February 2026

Terminology

The three categories

Our term DEGURBA official term Density threshold Cluster population
Urban Urban Centre ≥1,500 people/km² ≥50,000
Peri-Urban Towns & Semi-dense Areas (Urban Cluster) ≥300 people/km² ≥5,000
Rural Rural Grid Cells <300 people/km² N/A

A note on naming

We say Peri-Urban because it reads naturally for programme teams and funders. It maps exactly onto DEGURBA's Towns and Semi-dense Areas category.

Source Priority

One cascade, not a vote

Priority Source Resolution What it provides
1 · Primary GHSL SMOD 1 km grid Pre-computed DEGURBA classification with cluster analysis
2 · Fallback Kontur Population H3 Res 8 (~0.737 km²) Population density per hexagon
3 · Last resort WorldPop 100 m grid Population count per pixel

Why GHSL SMOD is primary

SMOD codes are the output of a full DEGURBA implementation by the EU Joint Research Centre. They already incorporate everything we would otherwise have to rebuild:

  • Density threshold filtering (300/km² and 1,500/km²)
  • Contiguity testing for connected grid cells
  • Cluster population validation (5,000 and 50,000)
  • Gap-filling and edge smoothing

We implement no cluster analysis of our own, because GHSL SMOD has done it correctly already.

What the fallbacks add

Where the 1 km SMOD grid is unavailable or ambiguous, the cascade steps down in resolution rather than guessing: Kontur hexagons carry real density estimates, and WorldPop pixel counts are the last resort before a location is flagged unclassified.

GHSL SMOD

Settlement model codes, mapped

Code GHSL name Our category
30Urban CentreUrban
23Dense Urban ClusterUrban
22Semi-Dense Urban ClusterPeri-Urban
21SuburbanPeri-Urban
13Rural ClusterRural
12Low Density RuralRural
11Very Low Density RuralRural
10WaterN/A

Fallback Layer

Kontur density thresholds

When GHSL SMOD is unavailable, classification falls through to Kontur population density:

Classification People per H3 Res 8 hexagon Equivalent density
Urban≥1,000~1,356 people/km²
Peri-Urban300 to 999~407 to 1,355 people/km²
Rural<300<407 people/km²

H3 Resolution 8 specifications

  • Average area: 0.737327 km² (737,327 m²)
  • Average edge length: 461 m
  • "400 m hexagon" is Kontur's shorthand, not actual dimensions

Compliance

Why this is DEGURBA-compliant

  1. Official primary source

    The primary data source (GHSL SMOD) is produced by the EU JRC using official DEGURBA methodology.

  2. Built-in thresholds

    SMOD codes incorporate cluster identification and the population thresholds DEGURBA requires.

  3. Derived fallbacks

    Fallback sources use density thresholds derived from DEGURBA standards, not ad-hoc guesses.

References