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I am looking for sources of geo-referenced data on villages and cities (or all other things there are) in The Gambia (and Senegal if available). One issue with geocoding in rural West Afrika is the varying spelling of village names.

I own a (possibly incomplete) list of some 2000 Gambian village names, I was able to acquire some 1000 coordinates from HERE maps, Google maps, and MapQuest, through the respective APIs. But I estimate that this is missing roughly half of the villages in The Gambia. What is more. Some of these one thousand are rather bad/uncertain matches, so it would be good to compare with additional sources.

Are there any other sources, with a decent level of detail and fairly up-to-date?

Here is a list of villages that I was not able to find with any of the above sources. Since I know for sure where they are located I use those as a benchmark:

(I am aware that some of these actually have labels with different spellings/entirely different names in google maps. However, this is so far of no help to me though, as these spellings mostly nowhere close to how the village names are usually spelled/pronounced)

Clarification in response to some comments: geonames for Gambia is in most cases rounded to minutes, which in the case of Gambia gives a grid in which places are as far as ~1.3kms, away from where they actually are. In the case of Gambian villages which are densely and rather uniformly distributed, this is not very helpful. If there are ways to obtain ungrounded geonames data I'd be happy.

  • diva-gis.org/gdata >Gambia > Gazetteer export as excel this contains lat/lngs of PPL (populated places) – Mapperz Aug 6 '15 at 14:27
  • Thank you. This is the same as the geonames.org? I'm not using it because it's rounded to minutes, and therefore not fine enough – sheß Aug 6 '15 at 14:36
  • Sounds like geocoding request like (Koli Kunda Gambia) maps.googleapis.com/maps/api/geocode/… will return the full coordinates – Mapperz Aug 6 '15 at 14:47
  • It sure does, but it doesnt for all villages, e.g. "Bati Khai, Gambia". This is what I meant with "I was able to acquire some 1000 Gambian coordinates from HERE maps, Google maps, and MapQuest, though the respective APIs. But this is missing roughly halve of the villages in The Gambia" – sheß Aug 6 '15 at 14:54
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    Hi... Did u try www.wikimapia.org this website has got more names then google as per what I have experienced. Areas have been demarcated by the local people as well, therefore, u might find what u require. I'm not the programming guy but this web also (if u click the coordinates in the left bottom corner) gives u lat long and degree decimal besides min n sec. I find locations manually but u might try the other ways of query. – Ade'l Aug 20 '15 at 12:05
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+25

you might want to try Overpass Turbo to extract villages from OpenStreetMap (see license). I tend to find OSM has better detail in some countries than Google Maps. And they should be more accurate than 1 minute resolution of Geonames.

Zoom the map to the extent you want, and use this query. This will return Geojson

[out:json][timeout:25];
// gather results
(
  // query part for: “place=village”
  node["place"="village"]({{bbox}});
  way["place"="village"]({{bbox}});
  relation["place"="village"]({{bbox}});
);
// print results
out body;
>;
out skel qt;

alternatively, use the wizard and search for 'place=village'. I tried this zoomed into the extent of the Gambia and got nearly 4000 place nodes.

enter image description here

You should also try 'place=town', 'place=city' and 'place=hamlet', to get all possible locations.

OSM allows for name translations and alternative names; find the ISO code for the language you want, and look for a field called name:[iso code], e.g. name:de for German. There's no guarantee they'll be tagged, but it's worth a try.

  • While (Overpass Turbo)[overpass-turbo.eu] seems to be a great resource. Most of your ~4000 points are in the west of Senegal. And it appears that the three example locations I mentioned in the my question do not show up – sheß Aug 18 '15 at 13:47
  • Yes, I see they're missing now - OSM coverage and data quality varies, due to it being built by volunteer contributions. I found a dbf file here (select 'Gambia' and 'Gazeteer'), although I wasn't able to open this in LibreOffice so I don't know if it will help. If you have Excel you could try opening it with that. – Steven Kay Aug 18 '15 at 22:45
  • Thank you @Steven. This file is based on Geonames GNS though, and unfortunately for me, this has rounded coordinates for the Gambia, which are somewhat useless as they can be quiete far off their actual location – sheß Aug 19 '15 at 8:05

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