Datasets
All datasets published by the Urban Data Center attach to a common set of Urban Agglomeration boundaries. The catalog below lists every available dataset with its grain, format, and version. The methodology paper covering boundary construction is forthcoming. See releases for the full changelog.
Our boundaries and datasets come at three different levels of granularity.
DDL Global Urban Boundary
Mega-agglomerations are one unit.
e.g. Delhi + Gurgaon + Faridabad + etc. are all one unit
Unique identifier: ua_id
ADM1 splits
Mega-agglomerations are divided at global ADM1 boundaries.
e.g. Delhi State, Delhi (Haryana), Delhi (UP) are each a separate unit
Unique identifier: ua_id + adm1_split_id
ADM2 splits
Mega-agglomerations are divided at global ADM2 boundaries.
e.g. Each district of Delhi is a separate unit
Unique identifier: ua_id + adm2_split_id
Urban Agglomerations and administrative splits
Each dataset is keyed to either a parent Urban Agglomeration boundary or to an administrative split of that boundary. ADM1 and ADM2 splits are derived by intersecting the parent UA polygon with administrative boundaries from GADM.
ADM splits are only produced for agglomerations where a meaningful partition exists. Specifically:
- An ADM1 split is included only when the UA spans more than one GADM ADM1 unit. If the entire agglomeration falls within a single province or state, no ADM1 split entry is generated.
- An ADM2 split follows the same rule at the district or county level — the UA must span at least two ADM2 units to produce a split.
As a result, small or compact cities may have a UA boundary record but no corresponding ADM1 or ADM2 split records. This is expected, not a data gap.
DDL Global Urban Boundaries
Urban agglomeration polygons with stable identifiers, published globally.
DDL Global Urban Boundaries ADM1 Splits
Administrative level-1 splits of parent DDL urban agglomeration polygons.
DDL Global Urban Boundaries ADM2 Splits
Administrative level-2 splits of parent DDL urban agglomeration polygons.
DDL Historical Urban Population
Population totals for DDL UAs, and UA-ADM splits, by year (1975–2025).