| 21 Apr 2024 |
 Jf L | #16526 | Missing Maps: Buildings in Sokoto, Nigeria (1)· task #135
Hi,
in my opinion, the green arrowed objects (see attached pic) correspond to buildings in construction. Am I wrong ?
Thanks in advance for your feedback . | 09:02:20 |
 dinar.adiatma | Omowonuola Akintola Jorieke Jorieke | 09:13:19 |
 Peter Elekes | Aren't those rather ruins? What are the coordinates on the pic please? | 13:15:09 |
| Jf L | 13.0164889, 5.1655243 will allow the visualization of the area of interest.
In my understanding, ruins means that the roof and at least in part some walls are destroyed. It does not seem to be the case here don't you think so ? | 17:25:05 |
| Peter Elekes | No idea, they might be open kettle yards as well | 17:46:12 |
| Peter Elekes | Well, then what are these? (Mtambile, Tanzania, -5.38175966,39.69873627) | 18:28:12 |
| Jf L | It is a bit tricky to understand what these structures correspond to. In my opinion they are possibly buildings in construction but the high number of these objects in the ROI is a bit surprising. Regarding coordinates 13.0164889, 5.1655243 , alternative imageries confirm that a series of squares correspond to buildings which construction have been finalized. The issue is that the confirmation can be obtained only for a limited proportion of the questionable objects. | 18:53:26 |
 Omowonuola Akintola | Yes Jf L, they are buildings under construction. | 20:10:48 |
| Omowonuola Akintola | Jf L as an addition, those places I marked in red are smaller circular huts that are very common in rural Nigeria. They are very easy to miss out while mapping | 20:18:10 |
| 22 Apr 2024 |
| Peter Elekes | I'd speculate (at least on my imagery from Tanzania, but is suspect it might be the case for many places in Africa or even South America) that these are buildings that wind or a storm have taken the roof off. Metal sheets roofs I think are susceptible for being torn in one piece. Or even taken down later if it gets partly destroyed. I'd highly doubt they'd be in construction due to plants, trees sprouting within. | 03:21:15 |
| Omowonuola Akintola | Peter Elekes You're absolutely right, those are strong possibilities. However, in the Nigerian context, buildings of that type are usually "under construction". Economic challenges or other unforeseen circumstances can sometimes lead to the construction being stalled, leaving them unfinished with vegetation growth becoming visible. | 08:03:32 |
| Peter Elekes | Omowonuola Akintola That's a good point! So basically we have no reliable way to determine which one is the case without eyes on the ground - good to know! And thanks for widening our perspective on this! | 08:05:34 |
| Omowonuola Akintola | Peter Elekes As a personal opinion, if the demarcation (red dots in the image) does not present any visible ruin, I'd most likely assume "under construction" | 08:14:16 |
| Jf L | Many thanks Omowonuola Akintola for your relevant remarks and comments. | 08:16:17 |
 Anna Zanchetta | Could they be called with a tag that could comprise both destroyed and stalled buildings, as “abandoned” buildings? Not sure if such a tag exists. Or maybe “stalled”…? | 09:46:07 |
 Henk Nugter | In task #230 of project #16178 there is a lune (untagged) and a river crossing multiple tiles in the wrong direction. | 15:06:19 |
| Henk Nugter | 
Download Schermafbeelding 2024-04-22 174440.png | 15:50:22 |
| Henk Nugter | 
Download Schermafbeelding 2024-04-22 174423.png | 15:50:39 |
| Henk Nugter | about mapping DRC Congo River floods response·#246
Is what we are doing usefull? If I compare the Bing imagery with Google map I see many differences, therefore I think that Bing imagery is very old.
I have copied the coordinates in Josm and did a search in google maps. The area seems the same but the the Bing imagery seems very old, How can I see the age of the imagery. | 15:50:40 |
| Peter Elekes | Henk Nugter I've been working on the same project and had the same question, it depends on the project leaders - if they want it off Bing, we need to follow them because that ensures consistency. This worked outside the cities, but then you'll find areas where some of it has been mapped with newer images from Maxar, which we can't verify anymore because they are unavailable. Other times we've used ESRI which is newer but very low resolution. I've asked the Validation Team and their take was 1. ask the project owner 2. keep valuable existing mappings (do not overwrite new mappings with data from old Bing imagery). It's a pain this project I know. | 15:56:23 |
| Peter Elekes | One remark about Google, we're not allowed to use it in any ways, even for verifying, their license explicitly forbids taking any data from their platform, even for crosschecking (how it can be verified is beyond me) - other than you admit you've used it of course...) | 15:59:06 |
| Henk Nugter | But it’s not forbidden to have a look in Google Maps as long you don’t use the data. I was just curious. | 17:15:52 |
| 23 Apr 2024 |
 Gilles | Open Buildings could be a good reference and it is publicly available I believe. | 02:32:13 |
| Peter Elekes | Gilles Thanks, I haven't heard of it, do you have a link please? | 02:33:15 |
| Gilles | https://sites.research.google/open-buildings/ Scroll down to "Explore the Open Buildings data" easy from there. | 03:37:09 |
| Peter Elekes | Wow, thank you! I only knew about Bin's similar project: https://github.com/microsoft/GlobalMLBuildingFootprints | 03:39:23 |
| Gilles | Interesting! Thanks for that. | 03:44:34 |
|  Valentina Buoro joined the room. | 22:32:23 |
| 24 Apr 2024 |
| dinar.adiatma changed their profile picture. | 01:17:22 |
| dinar.adiatma | Yes, the tag for abandoned building is exist Anna Zanchetta
https://wiki.openstreetmap.org/wiki/Key:abandoned:building | 01:51:30 |
