Have you ever asked yourself what are the TOP 25 cities in the world, based on the number of POI in OpenStreetMap ?
To my surprise, the number 1 city is not a European one, but a city in Japan, that have 121.154 POI
I have calculated all the poi from the following category’s : amenity, leisure, shop, sport, tourism, man_made, office
I did not include the historic POI, because when i filtered the world planet, i had extracted the history tag, instead of historic
I had converter the ways into polygons, and then combined the 2 data-sets into one.
Then i had counted, based on the bbox of the city, the number of POI in each of the cities. I will give here the TOP 25 cities by the number of POI
Waiting for your opinions, comments, etc
Rio Grande 85238
Comment from AgusQui on 9 September 2015 at 13:58
Río Grande ¿country?
Comment from tyr_asd on 9 September 2015 at 14:35
How did you define the bbox of a city? Because using the Overpass API, I would get significantly smaller numbers of objects (e.g. 18k for Essen or 31k in Dortmund: http://overpass-turbo.eu/s/blX). The numbers are even smaller when using exact city limits (e.g. 12k for Dortmund: http://overpass-turbo.eu/s/blW or 18k for Yokohama).
Comment from florinbadita_telenav on 9 September 2015 at 19:35
First of all Thank you very much !!! I did not know that you count in the search without displaying, i love overpass-turbo but i hated the fact that the browser was the bottleneck. this it`s a useful information.
I had a predefined list with around 1200 cities, having the bbox of them, from where i had created the polygons.
I got the bbox from a predefined list, , there is a square cut for each of the cities. there is the possibility when we have 2 or more towns close each close to each other, to count a POI that is in the other city.
A shapefile approach with the city limits would yield more real results, have to see what version could i approach to get the shapefile without spending to much time searching for it. ( My task with the POI it`s done, but for the future, i would like to have a more precise method of measuring.
for Essen the polygon it`s “
POLYGON((6.74042 51.2949,6.74042 51.6291,7.27687 51.6291,7.27687 51.2949,6.74042 51.2949))”
For Dortmund the polygon is :
“POLYGON((7.21538 51.3368,7.21538 51.6708,7.75182 51.6708,7.75182 51.3368,7.21538 51.3368))”
Comment from florinbadita_telenav on 9 September 2015 at 19:37
Comment from florinbadita_telenav on 9 September 2015 at 19:54
I was expecting to be something with Rio De Janeiro
Nop, its not, not sure how this end up on the list with the cities and what was the logic of this, its seems like the river was included
s not, not sure how this end up on the list with the cities and what was the logic of this, it
Comment from tyr_asd on 10 September 2015 at 08:27
Ah, I see. The city-area definitions are really quite different: https://gist.github.com/tyrasd/8a6b92618eaa2e1a02aa
Comment from florinbadita_telenav on 10 September 2015 at 09:28
I was expecting them to be bigger, so we can also have the airports and other POI that are near a city, but not with that much.
I will try to find the time after work to find a list with the most important cities from around the world, in a shapefile
Comment from Jedrzej Pelka on 10 September 2015 at 13:13
How about a statistic of POI-density in OpenStreetMap, in POIs per km² of city polygon?
Comment from trigpoint on 10 September 2015 at 16:45
I see that Birmingham is there, how did London and Nottingham do?
Comment from baditaflorin on 10 September 2015 at 17:27
@Jadrzerj Pelka I am thinking of redoing the gigapixel that i did last year https://photosynth.net/view.aspx?cid=cc38ddc9-5f75-45c9-8ee7-3d1388439a3e
and with that, some new statistics.
Comment from Sanderd17 on 23 September 2015 at 07:35
It would probably be more interesting to see POI density used in some way. Like POI per area unit, or POI per population.
Many cities have different boundaries that would yield different results. Like in the case of Brussels, there’s the municipality Brussels (aka Brussels city), and the Brussels-Capital Region. But about the entire Brussels-Capital Region grew together into one big city.
Brussels city has only about 170,000 inhabitants, but with an area of just 33 km², that’s about 5300 inh/km². Brussels Capital Region has 1,160,000 inhabitants, with an area of 161 km², which makes 7200 inh/km². So even though Brussels city is considered the city, it’s clear that the entire region is in fact the city, and selecting one of the two will make a difference in the measurements.
When counting the POI, Brussels city has 2627 POI (http://overpass-turbo.eu/s/bC4) and Brussels-Capital Region has 11491 (http://overpass-turbo.eu/s/bC6). That’s of course a serious difference. But Brussels city has 0.015 POI/inh, while Brussels-Capital has 0.009 POI/inh, and Brussels city has 80 POI/km², while Brussels-Capital has 71 POI/km².
So in both cases, I’d call Brussels city to be mapped better than the surrounding region, although in absolute number of POI, Brussels city has a lot less. I think it would be a lot more interesting to compare these POI densities rather than the absolute numbers.
Comment from wille on 4 October 2015 at 17:09
In Brazil there is “Rio Grande do Sul” and “Rio Grande do North”, both are states. In the first there is a city named “Rio Grande”, but it doesn’t have many POI’s http://www.openstreetmap.org/#map=14/-32.0429/-52.1041
I think your analysis failed on this case…