The blow instructions are from the GIS Day 2020 Mapathon. These directions only apply to project COVID-19 – Sipaliwini District 3, Suriname .

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 #UDGISDay20 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

  • Imagery: Please use Maxar Premium (beta) imagery. It has been set as the default imagery for this project.
  • Many of these squares will already be partially or fully mapped, map more if needed, fix up the existing mapping, or just mark it “Completely Mapped” if already done.
  • Only adjust landuse polygons if they are incorrect and affect your ability to map buildings; otherwise leave alone. Please do not attach them to buildings
  • Please do not change or delete preexisting building tags (e.g. addr:city = city name, addr:street=city street, amenity = restuarant, buildin = house, building = commercial, etc.)
  • Existing mapping does not match imagery – This happens in some areas, when different imagery sources are used. If this occurs, check to make sure that you are using Maxar Premium
    (beta) imagery. If necessary, addject the existing mapping to align with Maxar Premium (beta), then continue mapping.
  • Alternative image is better – Sometimes due to shadows, alignment and other factors it may be easier to trace features using other imagery. That is fine as long as you adjust
    for any offest. When finished please a comment in the Tasking Manager when you mark done/stop mapping to say you used alternative imagery.

Tracing Buildings Reference

  • Please watch this short video on mapping buildings
  • Please accurately outline all the buidling you find. The outline should be for the full size of the building even if it is partly covered by trees in the imagery.
  • Take care to not include building shadow in the building outline.
  • After drawing the outline and tagging as a building, use the ‘Q’ key in the Id & JOSM editors to “square” the corners. We suggest using the buildings
    plug-in in JOSM to make building tracing more efficient.
  • Mapping buildings close to each other without letting them connect or share nodes with other objects. In the iD web editor, holding down the “alt” key will
    keep nodes from “snapping”
    to each other and accidentally connecting.
  • In the ID web editor, you will only have the option to tag new features as buildings, see below for editing or adding other features.

Trace Roads and Other Features

  • Roads are being done in another project, only adjust roads if they are incorrect and affecting your ability to map buildings (i.e. crossing); otherwise leave alone.
  • Other features such as waterways, landuse, etc can be mapped but please do not do so via this Tasking Manager project as the other mappers will likely not continue a waterway you start (as example). Map these ‘traditionally’ through

Changes Set Comments

  • Adding the following to your comments when you finishing mapping: #UDGISDAY20 #hotosm-project-9725 #COVSURI #covid19 #Buildings for Basemap of Sipaliwini District, Suriname


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