OpenStreetMap

Mapping Pyongyang: a work of patience

Posted by Koreller on 1 October 2023 in English.

Mapping a large urban area in its entirety is quite a rare task.

Pyongyang, the city I mapped, is an urban area 15km wide by 12km long. It took me over a year from April 2022 to May 2023 to complete, particularly the buildings and roads. But I’m really pleased with the result: just look at the state of the map!

Mapping a capital in its entirety is rare, and for several reasons:

  • Firstly, because all the major urban areas in the West have already been mapped. This leaves the countries with the fewest contributors, whose capitals may already have POIs… but rarely all the buildings and roads.

  • Secondly, because you need a good amount of motivation, when you’ve reached the 60,000th building and you’re still halfway there… well… you have to hang in there! I also think it’s hard to imagine embarking on such a lengthy mapping project. Imagine if you wanted to undertake a project like this for Hanoi… unfortunately it can be discouraging from the outset.

But mapping by small parts, by neighbourhood, is a method that worked quite well for me, so maybe it will work for others!

In short, there are still many capitals to be mapped on these basic themes! But getting started, and above all keeping going, is a fairly difficult task because you need to stay motivated. If you do, hang in there!

Mapping Pyongyang

Beginning of the idea

When I started mapping in North Korea and writing the contribution guide to the country (cf. my previous diary) I never thought I’d be embarking on such a task because… it’s a capital in fact! It’s big, it never stops, it’s long, you never see the end of it! But in fact it is ;)

But I didn’t start mapping in North Korea by saying to myself “I’m going to map the whole capital”. In fact, for a long time I never even thought about it. In fact, it’s a project that’s taken place in several stages.

I started by mapping the small towns of Kowon and Kumya. Then I continued with medium-sized towns, such as Nampo western part — the eastern part of Nampo was done by Dwaalgast a very, very good contributor — and Kaesong, which are respectively the 4th and 9th largest town in the country.

A tweet, the trigger

Then one day, when I saw a tweet showing a map of a new district of Pyongyang (a district built in 2015, which in April 2022 was still not on the map…), I said to myself, “Yes, damn it! Why hasn’t anyone mapped this district right in the centre? This motivated me to map it, which was done fairly quickly in one, two changesets of April 2022! Then the person who had made the tweet accused me of having stolen his map, because this person (a researcher) didn’t know how mapping on OSM worked. I then had to talk to her to explain.

In the end, this enhanced what I consider to be a hobby on the Internet. I came to say to myself “what I do has a real value”. That really motivated me!

Mapping by small area, by district

That’s when I realised that it wasn’t just this new area in the city centre that wasn’t mapped, it was also the Songhwa area. (April 2022)

And the island in the centre too! (April 2022)

And the central district, the Phyongchon district, there was everything to do! (mid-May 2022)

And now why not tackle the big 1980s district, Tongil Avenue, in the south of Pyongyang, which hasn’t been done either! (end May 2022)

And the district to the west, Kwangbok, also needs to be done! (early June 2022)

And it was only at this point that I thought I might be able to map the whole of Pyongyang. That it was possible, and that I was motivated enough to do it.

Complete mapping

Then it’s a question of time, the whole undertaking took 1 year and 1 month. I took a lot of breaks. There were times when I was more motivated, so progress came in fits and starts.

Take a look at this GIF of the mapping progress. It’s approximate but gives a good idea of how long it took to complete each zone.

Pyongyang progress report

An incomplete task

In reality, I’ve gone back over certain areas several times and it’s still not perfect! I’ve noticed that among the first areas I’ve done there are a lot of small buildings that I haven’t mapped. So I’ll have to go over a bit more, but as the Maxar imagery hasn’t been working since the beginning of July 2023, I’ll do it at another time.

Continued

Today I’m still mapping Pyongyang and I’d also like to do more precise mapping (areas of grass, trees, street lamp, etc.). There’s still a huge amount to map, even more if you look at the scale of Pyongyang province, where all the other towns and rural areas are missing. I haven’t finished yet!

Image of the Pyongyang Province

Conclusion

Completing an area as large as a capital city requires a great deal of patience and, above all, motivation. It may be more appropriate to have fun improving just a small part of a city than to undertake to do everything straight away. The risk is that you’ll stop very quickly and become very demotivated, or even disgusted with cartography if you force yourself to do it.

In my opinion, it’s better to tackle small areas rather than trying to do everything.

What’s more, even if you stop at a small area, it’s not a big deal - it doesn’t prevent anyone from doing other areas later on. That’s the power of the OSM project: everyone can do what they want, if they want, at the pace they want!

Location: Kyongrim-dong, Central District, P'yŏngyang, North Korea

Discussion

Comment from pedrito1414 on 2 October 2023 at 06:24

Wow, this is really a labour of love. Thanks for sharing… Can I ask a question? You said motivation came and went… Was that because of the task ahead of you in the mapping or just other life stuff? (I ask as some of the neighbourhoods are really tricky dense buildings and I find them hard to map for long)

Comment from Koreller on 3 October 2023 at 08:11

@pedrito1414 No I was just taking about the mapping.

Of course it’s difficult to map buildings in dense areas, but in Pyongyang the architecture is fairly regular, so it can be done, and the available imagery is of good quality.

I don’t think it would be possible to do the same thing with Hanoi for example, because the shape of the buildings is very complicated to understand. If I mapped Hanoi from armchair too many approximations would be made for the quality I’m aiming for.

Comment from 快乐的老鼠宝宝 on 4 October 2023 at 13:22

Shocking of such patience and perseverance, but looks like North Korea still has so much to accomplish, this is a long and lonely march

I’m more curious about how you deal with the offset problem than this, because when I’m mapping some megacities (such as Beijing), it can’t be completed within a few years, and the base map provided by esri/maxar will be drawn three months later visit again, even if it is the same base map provider, there may be errors with the previous ones due to re-shooting. Have you ever dealt with similar problems during the drawing process?

Comment from Koreller on 5 October 2023 at 10:23

@快乐的老鼠宝宝 As I explain a little in the diary, I work by district. I go zone by zone, I adjust all the existing objects on Maxar with no offset (or on the imagery I intend to use) and then I map all buildings and roads of the area.

But there are places where I try to make something coherent even if it doesn’t match the imagery perfectly, by avoiding overlapping buildings and roads. I try to understand the relative positioning of these objects by changing imagery (Maxar, Esri, Esri Beta, Bing) to do my best !

Comment from kucai on 6 October 2023 at 00:53

Wonder how you get the boundary data for the district? In my country I don’t think there is any officially available district boundary data, and even then somehow people drew them (i knew where they got them though).

Comment from Koreller on 6 October 2023 at 06:57

@kucai I didn’t add any borders but it’s on Wikimedia Commons !

Comment from epicspongee on 7 October 2023 at 20:30

Just wanted to say, this is so cool! I always forget to do before / after screenshots of my map work, so I love love love the gif you made there. Super cool project and I think out of all the mapping providers online, this might be the most detailed map of Pyongyang!

Comment from Fnordson on 8 October 2023 at 11:43

I’ve been mapping NK for quite some time too, however the loss of Maxar hit really hard. Especially in the rural areas. Now I struggle with motivation.
Based upon your experience: what is the best alternative now?

Comment from CharliePlett on 8 October 2023 at 13:31

Yes, mapping piece by piece is important. When I was mapping Belize I created a grid overlay that divided the country into grids of 9 sq km, and then I mapped it grid by grid.

Comment from Koreller on 8 October 2023 at 14:52

@epicspongee In many ways, it’s the most detailed map of Pyongyang!

@Fnordson At the moment I use Bing because it’s the most pleasant imagery to use in South Hwanghae, but for Pyongyang it’s the Esri map that’s most up to date, so depending on the area I use one or the other. But we miss Maxar!

@CharliePlett How did you do it? I mean technically to create a grid overlay that divides the region into 9 km² grids?

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