generalized_tables:
  landcover_polygon_gen5:
    source: landcover_polygon_gen4
    sql_filter: area>15000000
    tolerance: 300.0
  landcover_polygon_gen4:
    source: landcover_polygon_gen3
    sql_filter: area>4200000
    tolerance: 200.0
  landcover_polygon_gen3:
    source: landcover_polygon_gen2
    sql_filter: area>1200000
    tolerance: 120.0
  landcover_polygon_gen2:
    source: landcover_polygon_gen1
    sql_filter: area>480000
    tolerance: 80.0
  landcover_polygon_gen1:
    source: landcover_polygon
    sql_filter: area>240000
    tolerance: 50.0
tables:
  landcover_polygon:
    fields:
    - name: osm_id
      type: id
    - name: geometry
      type: validated_geometry
    - name: landuse
      key: landuse
      type: string
    - name: natural
      key: natural
      type: string
    - name: wetland
      key: wetland
      type: string
    - name: area
      type: pseudoarea
    mapping:
      landuse:
      - allotments
      - farm
      - farmland
      - orchard
      - plant_nursery
      - vineyard
      - grass
      - grassland
      - meadow
      - park
      - village_green
      - recreation_ground
      - forest
      natural:
      - wetland
      - grassland
      wetland:
      - bog
      - swamp
      - wet_meadow
      - marsh
      - reedbed
      - saltern
      - tidalflat
      - saltmarsh
      - mangrove
    type: polygon