Mapper of the Month: Guirec Halflants (Belgium)

- escada

translation by Escada and Koninklijke

Who are you?

I am Guirec Halflants. I am originally from Brussels but live in Arlon at the moment. I always have been passionate about maps and I travel a lot using maps during the summer evenings. Later on, I invested in the Time Atlas of the World, which is outdated in the meantime. I also enjoyed the offer of a newspaper to publish a staff map of Belgium on a daily basis; I have the collection almost complete, tidily organised and folded but I almost no longer use maps on paper.

How and when did you discover OpenStreetMap?

I discovered OSM after buying my first smartphone and I looked for a way to use the GPS while being off-line. After that, I discovered dozens of applications on the net: OpenTopoMap, HOT (Humanitarian OSM Team), etc. I think what particularly appealed to me, was discovering that I could easily update the map myself; I started right away, I think.

What do you map? Did this change over time?

I learned a lot along the way. I started with the online editor and moved more recently to the JOSM, which allows to map much faster, to get rid of satellite photos and work with other layers, such as PICC in Belgium. There is however a small learning curve! I travelled a lot in 2012 - 2016, in Africa, Cape Verde and Latin America, and, as soon as I could, I looked on the map and saw the details that were missing: paths in the fields and woods for cycling, driving, hiking … There are countries where mapping is still embryonic and where one can really make a difference mapping large features! I started in earnest in May 2016 by mapping the small town of El Cuá in the Nicaraguan forest, based on very poor satellite photos and what I had seen on the ground. The map is now accurate and detailed! Once the main tracks and streams were traced, I started to look at the houses and buildings but that is more like mapping in Belgium or Europe.

How do you map?

That depends a bit on the “project”. In case of a systematic job, it is usually based on a map of type PICC or satellite photos in case no base map is available such as in the Nicaraguan woods. Sometimes, I notice a missing detail on my GPS, that can be a missing speed limit or building; I make a note (or try to remember) to fix it when I am back home.

How do you do surveys?

I do not do many of them. During my travels, I remember the way and what I see and compare that with the map, the background satellite photos and I change what I can. I am now looking to master a good offline mapping tool on the phone; I still have not quite found what suits me or understood the logic of the proposed tools but StreetComplete seems interesting.

Where do you map?

At this moment, we have a group of mappers in the south of the Luxembourg province that set the goal to map all the addresses of the various towns, starting with the ones closest to our home. This means drawing all the buildings and assigning the address tags. The idea is that the OSM data should be useable with any GPS for locating an address and guiding you there. Longer term, we hope that this can gradually serve the authorities; Arlon already seems to prefer OSM to other options on its website and in studies regarding mobility issues.

What is your biggest accomplishment?

I really enjoyed the experience of the “HOT” project in which I participated. We created a complete map of an isolated area in Rwanda with a group of mappers. The map would be used for the treatment against malaria in that area. In the beginning, there was not a single building, not a single road. And we did this together.

Why do you map?

Maps are beautiful, they allow you to travel in the real world or in your head without producing CO2.

What is the most difficult part of mapping?

Having good information about a place. Sometimes one needs more than photos and I did not start recording my movements; it interests me less, I leave that to others. I’m more for the quality of the rendering and the collection of details or what “structures” space.

What are your plans in the near future?

I want to contribute to the last part of the mapping of the addresses in Arlon and start in Attert a bit more to the north. After that, I would like to take my bicycle and map the nature and the important points such as the forests, roads and cultural items in Arlon and Attert.

Do you have contact with other mappers?

Yes, we have created a group of mappers around Arlon under the impulse of foxandpotatoes. The goal is to improve the map close to us and to promote the usage, both by public services and the general public. We also do a lot of promotion and training interested people.

Do you use OpenStreetMap yourself?

I use OsmAnd and ORUXmap, a Spanish project on my phone. I also found a way to use OSM on GPS devices of some well-known brands: (note: this site is causing problems lately, you use an alternatives such as This gives me an up-to-date map of any country. Moreover, the battery is not that good any more and I rely more and more on my phone.

Do you do anything for OpenStreetMap besides mapping?

I work for a development cooperative and I always look for opportunities to use OpenStreetMap. That can be a for a small map that one has to put in a report (I do mention the source and the open data license!), or for GIS applications, but I do not have a lot of first-hand experience with that.

I do use OpenStreetMap on the websites that I create to promote my activities in the region.

To conclude, is there anything else you want to mention?

OpenStreetMap is a good example of a crowd-sourced, free project and of the power of a community. I always wanted (but I lack the knowledge) to do that in software, but in cartography is achievable. Everybody can contribute a piece of useful geographical information, which can be improved by those with more knowledge.