Beginner’s guide to getting involved with the Humanitarian Open Street Map team

If, like me, you’ve always wanted to get involved in voluntary work that would benefit people in crisis-stricken areas but just blindly pushing money at the issue or dedicating months of your life and disappearing halfway around the world to directly help with the relief effort doesn’t really appeal to you, here’s a possible option:  Help to map the affected area!

The aim of the Humanitarian OSM team (hereby referred to as HOT), as stated on their wiki site (, is to promote “the creation, production and distribution of free mapping resources to support humanitarian relief efforts”. As a result, they have opted to use the Open Street Map platform, from which they can easily direct their efforts.

  • The creation of data is simple and, with the help of the HOT OSM Tasking Manager (which I’ll come back to later) tasks and areas can be split so that multiple contributors can work simultaneously to map buildings, roads and other important features within the area affected by a particular crisis.
  • Extracts from the dataset can be taken quickly and easily (for free!), meaning that the (often considerable) updates can be passed out regularly to those working on the ground to keep them up to date.

Sound good? Here’s how to get involved.

First, you’ll have to sign up for Open Street Map in order to edit the dataset. To do so, go to the following link Make a note of your username/password, you’ll need to use it later.

Now, you’ll need to decide which editor to use. For the purposes of this guide, I’m going to use JOSM, because although it may take a bit of getting used to for new users, it is specifically designed for editing OSM data, and is well worth learning. There are alternatives, such as an ArcGIS plugin, details for which can be found here:.

Anyway, off we go. JOSM, a desktop editor for OSM, can be downloaded from here

Choose the relevant installer; it’s available on Windows, Mac or Linux. Install the software and open it. If it fails to install, try installing Java first

Now, we’ll want to head over to the aforementioned HOT OSM tasking manager, which can be found here. If you type “haiyan” into the search, it’ll automatically update the results list, and you can see the current tasks for this crisis. It also gives the current completeness of each job.


Click on a job you’re interested in doing that hasn’t been completed to 100% (I recommend starting off with a job which is marked ‘initial mapping’ rather than post disaster, but it really is up to you.) Have a read through each of the tabs, then go to the ‘task’ tab, and click on one of the grey squares on the map or ‘take a task’ to get a random square.


Within JOSM, go to edit>preferences> 

Click ‘enable remote control’, and click OK. You may have to do this every time you re-open JOSM.

Back in your browser, the ‘task’ tab will have changed, allowing you to click on the JOSM button, which will automate the process of grabbing the data for the square you’ve selected.


In JOSM, you should see the OSM data added, and a square with the area surrounding it hatched out. You should not edit this hatched area at all, because this data has not been downloaded from OSM. The only features you will see in this area will be those that overlap the square you’ve been given.


For the ‘initial mapping’ jobs, go to the ‘imagery’ drop-down in JOSM, and choose Bing. For the post-typhoon mapping, you’ll need to add the imagery you want to use: Copy the TMS (tiled map service)/URL link for the imagery from the tasking manager, open preferences in JOSM, go to the ‘WMS TMS’ tab, and click the add button on the right of the dialog box. Paste the TMS/URL link into here, making sure to remove one of the “tms:”  if it says “tms:tms:” ; otherwise it won’t work.

Great work! You’re ready to edit!

First of all, I recommend you look at the short (I promise) tutorial on drawing and selecting with JOSM. When you’ve done so, come back here!

Have a go in JOSM, just to get used to it. Remember you can always close JOSM without saving and reopen the project with the remote, or delete any changes before continuing.

Now you can use the drawing tool to draw around the buildings and along the roads that you can see on the satellite imagery. You can also use the buildings_tools tool, which makes the process easier, but you have to search for and download it from “plugins” in the preferences dialog. If your building is not rectangular, you can use the create areas tool to extend the building as shown in this video.

For each feature, you should add tags in the ‘tags’ docked dialog on the right of the JOSM window, or set the relevant preset from the ‘presets’ dropdown. For example, if you’ve digitised a building, tag it as one. (i.e. go to the tags dialog and click Add. For the ‘key’, type “building” and for the ‘value’, just type “yes” (unless you know what type of building it is!)) You should also tag it with a source: use tag entries “source” and “Bing” (for example). If doing a post-disaster mapping task, you will also need to add other tags, as mentioned in the Tasking Manager.


note the source is not likely to be bing if typhoon:damage is known

Note that if you want to tag multiple features, don’t drag a selection box over everything, this will select both ‘nodes’ and ‘ways’(lines), meaning that each node would be tagged as a building as well as each ‘way’, which is not the case. Select a feature by clicking one of its ‘ways’, and use the shift key to add to the selection, or ctrl to remove from the selection.

I like to be able to see the features I’ve modified, so I’ve modified the mapcss file ‘Modified objects’ by Sebastian Klein, provided with JOSM, to be a bit more subtle. It also highlights features tagged with “typhoon:damaged=yes”  to help with post-disaster mapping. You can get it here. To add it, click the tab in JOSM that looks like a paint palette, and when the docked dialog appears, click the preferences button at the bottom right. Click the + button and either add the link (right click the above file and copy link location or save the file to your computer and link to that). I find having the default JOSM style on makes it difficult to see the imagery underneath.

Once you’ve made the changes you want to make, go to file>upload data and follow the steps. Enter your username and password and it should update the OSM server. Make sure your edits are correct, though, because you’re updating the live dataset! (Although changesets are reversable with a bit of effort.) Go back to the tasking manager and ‘mark task as done’, or if you haven’t finished, or aren’t comfortable with marking it as done, unlock the square so someone else can check/finish it off.


I’ve tried to fill this guide with as many problems that I came across as I could, and ways in which to fix them, so sorry if it’s not the most straightforward guide. Any questions or suggestions, feel free to comment (I will happily add to the mapcss file if anyone has good ideas!)

For (possibly) quicker answers, there is a chatroom: When logging in, choose #hot from the channel list and pick a nice username.

Thanks for reading and for your help!

3 thoughts on “Beginner’s guide to getting involved with the Humanitarian Open Street Map team

  1. Pingback: Weekly OSM Summary #82 | OpenStreetMap Blog

  2. Pingback: 週間OSMサマリ #82 | OpenStreetMap Blog

  3. Pingback: OpenStreetMap Chile » Blog Archive » Resumen Semanal OSM #82

Comments are closed.