- Entities to Map
- roads, buildings, residential areas, waterways, bridges, fords, dams
- Changeset Comment
- #hotosm-project-788 #ewb_australia When saving your work, please leave the default comment but add what you actually mapped, for example "added buildings and a residential road".
Mapathon Project for Engineers Without Borders Australia please only map as part of that event
General Mapping Notes
- Be as precise as possible - This takes a little bit of practice, but following a road closely or the outline of a building carefully really makes a difference in the quality of map data produced. Quality is more important than quantity when it comes to mapping. Zooming in close helps.
- Personal knowledge - If you have local knowledge, that is incredibly valuable and any information you are 100% sure of you can add to the object you are mapping. Building names, health facilities, names of roads, etc, are all very valuable and the name= tag can be used to supply that information.
- Sometimes a task square is already mapped - Sometimes you will find a task square that looks totally mapped or has nothing in it to map. Just double check that it is complete, map anything that was missed, straighten up anything that needs it and then mark it "Done".
- Invalidated task squares - You might get a notice that a task square was "invalidated" that almost always just means someone found a few more things to map and they did not have time to map them in. No worries, it is part of the process and happens all the time. If you have to stop mapping before you have mapped everything use the "Unlock" link instead of "Done" As long as you are trying to map everything in a task square you feel confident mapping before you mark one "Done" then all is good.
- Ask questions - if you have questions, please ask, the front page of this HOT Tasking Manager website offers a few ways to ask or if you are at a mapping event, raise your hand and ask.
- You are making a real difference mapping - Every contribution matters in a real, tangible way. Mapping in not easy but know that your mapping is used by humanitarian organizations around the world every single day.
Roads and Paths
- Please map roads and major paths as completely as possible by connecting them to the main road networks where ever possible.
- Very short segments that do not connect to anything should not be mapped.
- Short segments of a road or path that you cannot see through the trees but seem very likely to exist should be mapped to keep the road complete
- Try and map a little beyond your task square so the person who maps the task square next to yours can easily connect them.
- Always connect roads to other roads where they meet and never end roads on Residential area polygon edges.
You will most often use the following road classifications:
- highway=unclassified - This is for roads that a vehicle with 4 wheels could travel on that connect small villages and settlements
- highway=track - This is for roads that a 4 wheel vehicle or farm tractor could travel on and only lead to farm fields or forests. They do not connect settlements.
- highway=path - This is for small paths that a 4 wheeled vehicle could not travel on and are usually used by people on foot or 2 wheeled vehicles. They may or may not connect settlements or lead to farm fields. Only map the major paths that connect to settlements or other roads.
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. After drawing the outline, use the 's' key in the web 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.
In the iD web editor, the first time you map a building you will use the "Building" category and then at the bottom of the list select "Building" again, this is the most generic building tag we can use as we almost never can tell the more specific use of any building from imagery alone.
If you have personal knowledge of a building, please add that information to the building, like the name or type of building (hospital, school, gas station, etc)
In addition to mapping the individual buildings, please draw one large area outline around groups of buildings, usually about 5 or more buildings and label these as "Residential Areas". Do your best to keep the outline close to buildings and not include a lot of farmland or forest. When to draw the residential area outline takes some judgement, but when in doubt, draw an outline around the settlement.
Waterways, Bridges, Fords, Dams
- waterway=river - If you see obvious waterways, please map them. They are usually much lighter color, grey than roads/paths and you can often see rocks and split channels. Much like the road system, please find where the waterway connects to the main waterway network and map it to connection. Mapping waterways implies a direction as well so zoom out, look for already mapped waterways nearby, or use the OpenCycleMap background layer to help determine which direction the water flows.
- bridge=yes - This tag is placed on a segment of road that is just the same size as the bridge and also needs a tag that says layer=1 to indicate it is above the waterway. The waterway and the road do NOT share a node.
- ford=yes - If you see a road crossing a waterway try to confirm a bridge or a ford. Fords are places where the road just drives through the waterway. To map a ford, have the waterway and the road share DO a node and put the ford=yes tag on that one single node.
- waterway=dam - Dams are a little confusing to map, please see the references listed below and ask a more experienced mapper to help you. But they are important to map if you can identify them.
The OSM Wiki is where you can find detailed information on how to tag objects, below are some of the most relevant pages to typical humanitarian mapping projects.
- Highway Tag Africa - An excellent guild to typical humanitarian road mapping
- Highways, Roads, Paths - More than you want to know
- How to Map a Dam