README.md

map-data

Collection of topojson boundaries to be used for building map visualisations

Available data:

UK

Administrative:

• Local Authority Districts (UK): May 2024, Dec 2023, May 2023, Dec 2022, May 2022, Dec 2021

OECD/Eurostat:

• ITL1 - International Territorial Level 1 (UK): 2025, 2021
• ITL2 - International Territorial Level 2 (UK): 2025, 2021
• ITL3 - International Territorial Level 3 (UK): 2025, 2021
• NUTS1 - Nomenclature of Territorial Units for Statistics 1: (UK 2018), (England & Wales 2015)
• NUTS2 - Nomenclature of Territorial Units for Statistics 2: (UK 2018), (England & Wales 2015),
• NUTS3 - Nomenclature of Territorial Units for Statistics 3: (UK 2018), (England & Wales 2015)

Census:

• Lower layer Super Output Areas (England & Wales): 2021, 2011, 2001
• Middle layer Super Output Areas (England & Wales): 2021, 2011, 2001

Electoral:

• Westminster Parliamentary Constituencies (UK): Jul 2024, Dec 2021, Dec 2020, Dec 2019, Dec 2018, Dec 2017, Dec 2016
• Westminster Parliamentary Constituencies (GB): Dec 2015

Home Nations:

• United Kingdom (ENG, NIR, SCT, WLS): CTRY_UK
• Great Britain: CTRY_GB
• England & Wales: CTRY_EW
• Nations: England, Northern Ireland, Scotland, Wales,

USA

• States: states_2017
• Counties: counties_2017

Cities

• New York:
  • Boroughs: boroughs
  • Zip code tabulation areas: zcta

World

• Countries: world

Mapping with TopoJSON in Vega-Lite / Altair

1. Get the raw GitHub file link to any of the TopoJSONs:
   • "https://raw.githubusercontent.com/jhellingsdata/map-data/refs/heads/main/{folder}/{map_filename}.json"
   • "https://raw.githubusercontent.com/jhellingsdata/map-data/refs/heads/main/gbr/ITL1_UK_2021.json"
   • TIP When viewing large files in GitHub, it may not show a button to access the 'raw' file. In these cases, add ?raw=true to the page URL and it will redirect to the raw link, which can then be copied.

Note: all TopoJSONs in this repo use the geog feature key.

In Altair (Python)

import altair as alt

topo_url = "https://raw.githubusercontent.com/jhellingsdata/map-data/refs/heads/main/gbr/ITL1_UK_2021.json"
data = alt.Data(url=topo_url, format=alt.DataFormat(feature='geog', type='topojson'))

alt.Chart(data).mark_geoshape().project(
    type='mercator'     # Find other projections here: https://vega.github.io/vega/docs/projections/
)

In Vega-Lite:

{
    "$schema": "https://vega.github.io/schema/vega-lite/v5.20.1.json",
    "data": {
        "url": "https://raw.githubusercontent.com/jhellingsdata/map-data/refs/heads/main/gbr/ITL1_UK_2021.json",
        "format": {"feature": "geog", "type": "topojson"}
    },
    "mark": {"type": "geoshape"},
    "projection": {"type": "mercator"}
}

TopoJSON works a bit different than GeoJSON in Vega-Lite/Altair. We set the 'feature' instead of the property for xyz..