Documentation v0.3.0

DDL Global Urban Boundaries ADM1 Splits

Administrative level-1 splits of parent city polygons.

View downloads in catalog Jump to schema

Granularity: ADM1 split
Format: GeoPackage
Time resolution: Static
Module version: v0.3.0
License: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Coverage and granularity#

Released ADM1 splits of qualifying parent cities. Not every parent has published splits, and the published pieces may not cover its whole area.

This schema describes a split file in the urban boundaries package. Counts below describe that whole package.

9,849 of 9,849 parent cities · static · 13,366 rows across the package

City: 9,849 of 9,849 boundary IDs
ADM1: 387 of 387 boundary IDs
ADM2: 3,130 of 3,130 boundary IDs

Row key: id

Examples in the Boundary Explorer: New Delhi, Manila, Tokyo.

Joining this data#

A Python example using GeoPandas and pandas. Replace the file paths with your local downloads. See boundary levels and join keys.

import geopandas as gpd
import pandas as pd

# Match the boundary file to the module's geographic level.
level = "ADM1"
boundaries = gpd.read_file("adm1.gpkg")
observations = pd.read_parquet("ddl-population-historical.parquet")
observations = observations.loc[observations["boundary_level"].eq(level)]

joined = boundaries.merge(
    observations, on="id", how="left", validate="one_to_many"
)
print(joined.head())

Schema#

Name	Type	Units	Description
`id`	`string`	—	City identifier.
`parent_id`	`string`	—	Parent city identifier.
`adm_id`	`string`	—	GADM ADM1 identifier used to split the parent boundary. May be null.
`name`	`string`	—	City name.
`population`	`int64`	people	Estimated population within the split boundary.
`alpha3`	`string`	—	ISO 3166-1 alpha-3 country code.
`area`	`float64`	m²	Area in square meters.
`geometry`	`geometry`	—	ADM1 split boundary polygon. Coordinate system: EPSG:4326.

Notes#

The parent city is the reference geography for the city profile. Its identifier connects the published tables.
We drop small pieces of the parent boundary, so combining split boundaries may not reconstruct the full parent polygon.

Citation#

When using these data, cite Urban Growth Center and the original source below, where applicable.

Urban Growth Center

Development Data Lab. (2026). Urban Growth Center. https://cities.devdatalab.org/