Friday, May 6, 2016

GeoNames

GeoNames allows you to find the geographic coordinate of locations across the world, by typing the name of a location.

The website is useful to geo-reference your data if the location name is available.

If you have a lot of observations, however, using the web search is costly to do. A possible way to get around is to download the entire data of GeoNames. This page lists the zip files each of which contains all the locations in a particular country (see here to understand which file is for which country). This file can then be merged with your data by location name, which does geo-reference your data.

The list of variables (called fields) in the data (taken from the bottom of this page):

geonameid         : integer id of record in geonames database
name              : name of geographical point (utf8) varchar(200)
asciiname         : name of geographical point in plain ascii characters, varchar(200)
alternatenames    : alternatenames, comma separated, ascii names automatically transliterated, convenience attribute from alternatename table, varchar(10000)
latitude          : latitude in decimal degrees (wgs84)
longitude         : longitude in decimal degrees (wgs84)
feature class     : see http://www.geonames.org/export/codes.html, char(1)
feature code      : see http://www.geonames.org/export/codes.html, varchar(10)
country code      : ISO-3166 2-letter country code, 2 characters
cc2               : alternate country codes, comma separated, ISO-3166 2-letter country code, 200 characters
admin1 code       : fipscode (subject to change to iso code), see exceptions below, see file admin1Codes.txt for display names of this code; varchar(20)
admin2 code       : code for the second administrative division, a county in the US, see file admin2Codes.txt; varchar(80) 
admin3 code       : code for third level administrative division, varchar(20)
admin4 code       : code for fourth level administrative division, varchar(20)
population        : bigint (8 byte int) 
elevation         : in meters, integer
dem               : digital elevation model, srtm3 or gtopo30, average elevation of 3''x3'' (ca 90mx90m) or 30''x30'' (ca 900mx900m) area in meters, integer. srtm processed by cgiar/ciat.
timezone          : the timezone id (see file timeZone.txt) varchar(40)
modification date : date of last modification in yyyy-MM-dd format




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