Brexit¶
import geopandas
import topojson
import matplotlib.pyplot as plt
Local Authority District (LAD) geometries¶
The original geometries are downloaded from the Office of National Statistics through data.gov.uk
and stored locally:
lads = geopandas.read_file('./Local_Authority_Districts_December_2016_'
'Generalised_Clipped_Boundaries_in_the_UK_WGS84/'
'Local_Authority_Districts_December_2016_'
'Generalised_Clipped_Boundaries_in_the_UK_WGS84.shp'
)
Topology simplification¶
To obtain a much more lightweight set of geometries, we simplify the layer, respecting its topology. First we build the topology:
topology = topojson.Topology(lads)
Then simplify it:
simple_uk = topology.toposimplify(.025)
Inspect the resulting geography:
simple_uk.to_gdf().plot()
<AxesSubplot:>

And we can write it to a GeoJSON file:
simple_uk.to_gdf().to_file('./local_authority_districts.geojson', driver="GeoJSON")