DDL Global Urban Boundaries

Package scope: Global ADM1 urban agglomeration splits
Release version: v0.3.0
Reference year: 2025
Feature count: 387
Archive filename: ddl-urban-boundaries-adm1-global-v0.3.0.zip

Contents
- One GeoPackage with a single `urban_boundaries_adm1` layer
- This README

GeoPackage schema
- id: DDL city identifier. Stable across releases.
- parent_id: Parent DDL urban agglomeration identifier
- adm_id: Source GADM administrative identifier for the split
- name: City name.
- population: Estimated population of the city.
- alpha3: ISO 3166-1 alpha-3 country code.
- area: Geometry area in square meters.
- geometry: Urban boundary polygon. Coordinate system: EPSG:4326.

Joining and coverage
- Join module observations to this file on id alone; filter boundary_level to match the file first.
- Split files contain released administrative intersections for qualifying parents, not every parent in the global file.
- Published splits may not cover the whole parent polygon. Do not treat their summed areas or measures as parent totals without checking completeness.
- parent_id links a split to its parent; adm_id identifies its source GADM unit, not a module join key.

Coordinate reference system
- EPSG:4326

License
- Released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Disclaimer
By accepting data provided by the Development Data Lab (DDL), you agree to the following conditions of release and acknowledge the following disclaimers: Neither DDL nor the contributors of data to DDL shall be held liable for any improper or incorrect use or application of the data provided, and assume no responsibility for the use or application of the data or information derived from interpretation of the data. In no event shall DDL or its collaborators be liable for any direct, indirect, or incidental damages arising from the use or application of these data. This disclaimer of liability applies to any damages or injury, including but not limited to those caused by any failure of performance, error, omission, defect, delay in operation or transmission, computer virus, alteration, use, application, analysis, or interpretation of data. No warranty, expressed or implied, is made regarding the accuracy, adequacy, completeness, reliability, or usefulness of any data provided. These data are provided on an "as is" basis. All warranties of any kind, express or implied, including but not limited to fitness for a particular use, freedom from computer viruses, and non-infringement of proprietary rights, are disclaimed. Data are added and changed periodically, and data may become out-of-date quickly. It is recommended that the user not let a significant period of time elapse between obtaining and using the data.
