Polygons

Largest Parks in Leeds

Which parks are the largest in Leeds? Elevation adds detail.

Largest parks in Leeds.

Data

• OpenStreetMap data for parks within Leeds downloaded via QuickOSM plugin.
• Environment Agency Lidar data - 2m DSM composite
  • Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved. Open Government Licence.

Tools used

• QGIS.
• Inkscape.

What did I learn?

• Refreshed myself on how to use an atlas layout in QGIS.

What could I do differently or want to find out?

• Would have been useful to take more time with the layout.

Process (more detail about how I made the map)

Preparing park outlines

• QGIS QuickOSM plugin to download polygons for parks within Leeds - leisure = park.
• Only including those with names using Select by expression - "name" IS NULL. Toggle editing and delete unnamed polygons.
• Export results to GeoPackage with CRS = EPSG:27700 (British National Grid).
• Use OSMInfo plugin to get Leeds boundary polygon and again, export as EPSG:27700.
• Add area field to parks table - Field calculator: round($area / 1000, 2)
• Select parks with an area of over 150 km2 - Select by expression - $area > 150000 and save to a new layer.

Preparing Lidar data

• Download and merge the tiles of 2m DTM.
• In QGIS - Clip raster by mask layer using the large parks layer as the mask.
• Style the DTM in green colour ramp.
• Duplicate the DTM layer and style duplicate as hillshade. Put above DTM and use Multiply blending mode plus a little opacity. Set Resampling to Cubic for smoother effect.

Exporting park images

• Using Atlas layout in QGIS.
• Export each page as an image, setting output file names to name and area attributes.

Layout with Inkscape

• Import all images and layout as required before exporting as png.