The blow instructions are from the EARTH Day 2022 Mapathon. These directions only apply to project Urban Water Scarcity, Enugu, Nigeria: Enugu Building Basemap.

As you edit, you will notice a number of edits on the top toolbar. Save your edits periodically. We ask that you use the hashtag #UDEARTHDAY22 when saving so we can track your contribution.

There is a guide with images on the project page. The text is also copied below.

Project Specific Mapping Notes

  • A few of these squares may already be partially mapped, please review and map missing features if needed, fix up the existing mapping, or just mark it “Done” if already completely well mapped.

Imagery Notes

  • Please use Bing Imagery, in case Bing has clouds cover, switch to Digital Globe Premium.

Tracing Buildings Reference

  • Please accurately outline all the buildings you can find. The outline should be for the full size of the building even if it is partly covered by trees in the imagery
  • Most buildings are rectangular, after drawing the outline, use the ‘Q’ key in the JOSM editor to “square” the corners.
  • Many buildings are very close, but do not actually touch each other, try to map them close to each other without letting them connect or share nodes with each other, roads or residential area outlines.

Changes Set Comments

  • Adding the following to your comments when you finishing mapping: #UDEARTHDAY22 #hotosm-project-12361 Buildings mapping #enswc #waterandsanitation #sdg


  • The shortcut to create a new building is ‘3’.
  • To square a building, type ‘S’ after you select the feature as a building.

Start Making Edits to Map