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*Guest post by Kathryn Davis, Columbia University*


January 14th, 10:30 am. We arrive in Chang’ombe ward (an industrial area in Dar es Salaam) after weaving in and out of traffic in the project bajaj (rickshaw) through different neighbourhoods. Johannes Peter, a seasoned mapper with the Dar Ramani Huria project, takes another look at his drone imagery printout of the area and indicates that we’ve arrived at our starting point. He starts the OSMTracker app on his phone, ready to start work (the tracker app helps him to geolocate, and take pictures of interesting areas, with the pictures tagged to a GPS location). Mappers like Johannes detail key drainage and water infrastructure that hasn’t been digitized before and that can be used for disaster risk reduction planning and flood resilience. He stops to check the map again, and then we’re off looking for drainage systems (our main task for the day). Carolina and I (two Columbia University graduate students, here on a preliminary trip to evaluate the project) are tagging along on a regular day for the Dar Ramani Huria project, to see the work team members are doing in the field.  It’s not easy work, but essential to the project.


Almost immediately, we see drainage on the right side of the wide dirt road and mark it on the map. Johannes quickly identifies where we are on the map, and starts using the OSM Tracker App to identify the drainage, and to note indications of garbage or other debris blocking it.  He uses his phone to photograph this: the Tracker App automatically geotags the image, to give a visual for other OSM map users. All the data that Johannes collects today will be “digitized” (added to the online map) later, so it’s crucial to get details right, and we spend time noting each part of the drainage system that we can see, including the direction of water flow, which might indicate a drainage convergence at that point, or where drainage ends abruptly with no continuation. Johannes is systematic in his mapping: we cross part of the outer perimeter of the ward, then move down inner roads, stopping each time to note important drainage details.


By now we’re halfway through and the midday sun is shining on us, but with a quick water break we’re off again, to finish the area we’ve been assigned for the day. We see drainage under construction: Johannes indicates that on the map too, as drainage on these roads is likely to change in the coming weeks. We also see that part of one of the roads is flooded after light rain the day before. Drainage can go underground,  or we may need to figure out where the road is from the map: walking these roads and mapping takes a person who is comfortable asking questions, and Johannes, who’s from the city, is always ready to ask people in the neighbourhood he’s mapping for help, whether it’s for directions or the name of someone who might know where the non-visible drainage lines go.


After a day in the field, Johannes brings the now annotated maps to BUNI Innovation Hub to digitize. BUNI which is where the HOT team works from in Dar es Salaam when they are not in the field mapping. At this phase in the project, mappers typically work two days in the field, then one day digitizing their field data into the OSM platform. The 22 mappers currently on the project (most of whom have been there since the initial mapping in early 2015), have mapped many wards in the city of Dar es Salaam. The project was completed in detail infrastructure of 21 wards in Dar es Salaam and is now finishing a review of the drainage in these wards, and mapping 32 additional wards.

As we’re pulling away in the bajaj at the end of the day, we asked Johannes about using the data, mapping and being part of the project. He told us that “we are the Humanitarian OpenStreetMap Team. Humanitarian means that we are taking care of people, and this means that some things we have to do voluntarily”. Most of the main mappers (including Johannes) have recently obtained university degrees in urban planning or geography, and are extremely passionate about their work. When he visited the Katavi Region in the southern part of Tanzania to visit family, he saw there were no maps, so he started mapping the area using the skills from he learned from the project. For Johannes, mapping isn’t just what he does at work with the Dar Ramani Project. It’s also something he does in his free time.

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