JacobWeinbren / Tree-Cover

Tree Cover England

This project analyses tree cover and income deprivation data for Lower Layer Super Output Areas (LSOAs) in England.

Data Sources

• LSOAs England and Wales - Converted to WGS84
• Tree cover data
• Buildings data - Converted to WGS84

Data Processing

The data processing is done using Python scripts located in the scripts directory:

1. merge.py: Merges the tree cover and income deprivation data based on LSOA codes.
2. process.py: Combines the merged data with the LSOAs GeoJSON file, updating the GeoJSON features with tree cover and income rank properties.
3. intersect.py: Filters the updated LSOAs GeoJSON file and intersects it with the buildings data to create a new GeoJSON file with intersected buildings.

Commands

The following commands are used to generate vector tiles from the GeoJSON files:

Splits the large buildings file

    python scripts/split.py

Simplifies the large buildings files

    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part01.geojson -simplify 10% keep-shapes -o output/split/simplified_part01.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part02.geojson -simplify 10% keep-shapes -o output/split/simplified_part02.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part03.geojson -simplify 10% keep-shapes -o output/split/simplified_part03.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part04.geojson -simplify 10% keep-shapes -o output/split/simplified_part04.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part05.geojson -simplify 10% keep-shapes -o output/split/simplified_part05.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part06.geojson -simplify 10% keep-shapes -o output/split/simplified_part06.geojson
    node --max-old-space-size=32000 /usr/local/bin/mapshaper -i output/split/part07.geojson -simplify 10% keep-shapes -o output/split/simplified_part07.geojson

Combines the large building files

    python scripts/combine.py

    tippecanoe --output=output/filtered-LSOA.pmtiles \
           --layer="filteredLSOA" \
           --no-feature-limit \
           --no-tile-size-limit \
           --detect-shared-borders \
           --coalesce-fraction-as-needed \
           --coalesce-densest-as-needed \
           --coalesce-smallest-as-needed \
           --increase-gamma-as-needed \
           --coalesce \
           --reorder \
           --minimum-zoom=0 \
           --maximum-zoom=17 \
           --force \
           --simplification=20 \
           output/filtered_LSOA.geojson

    tippecanoe --output=output/tree-buildings.pmtiles \
           --layer="treeBuildings" \
           --no-feature-limit \
           --no-tile-size-limit \
           --detect-shared-borders \
           --coalesce-fraction-as-needed \
           --coalesce-densest-as-needed \
           --coalesce-smallest-as-needed \
           --increase-gamma-as-needed \
           --coalesce \
           --reorder \
           --minimum-zoom=0 \
           --maximum-zoom=17 \
           --force \
           --simplification=20 \
           output/simplified_buildings.geojson