> .....e all reference to number of inhabitants, & > base the decision on each mappers own recognition of how "important" > this is, so an isolated "village" with only a few hundred people > in it, but which is the main centre for this area will be a town, & > maybe even a city? ... No 'one set of rules' is going to match world wide. .... > One guide should be that surrounding places must be relative in level of > important to the place that is being mapped. ...Necessity makes this > population centre very important for the few people living in that area. ... (etc.)
Fundamentally, you are attempting to make a categorization of the rankings in the distribution of counts ( population ) of some subset of a domain. Economist Xavier Gabaix in 1999 wrote a much-cited paper describing Zipf's law for cities as a power law ( see https://io9.gizmodo.com/the-mysterious-law-that-governs-the-size-of-your-city-1479244159 ). It's been repeatedly tested over decades according to what conditions it holds or does not. Organizations that provide wide area web cartography using a wide range of zoom levels usually use some form of it, and it's available pretty much in every GIS software's symbolization set for this reason. There are some edge cases where mega-metropolitan areas merged together, and at the very bottom bottom literally in the weeds where one might be counting a few huts, but it's very robust, and more importantly there are proxy indicators which can stand in for the absence of direct population counts. But it's not really sensitive to 'accuracy' except at the very top end. So people have used road miles,extent area, night time lights, and other statistics for the ranking. ( See https://blogs.cornell.edu/info2040/2016/11/13/zipfs-law-for-cities-a-simple-explanation-for-urban-populations/ ): " Zipf’s Law does not just hold true for cities in the United States, but rather it has been correlated with urban population totals in nearly every developed country across the world. Additionally, works well when “Metropolitan Areas” are used – cities defined by the distribution and connectivity of populations rather than arbitrary political boundaries." In case of OSM, if the original count rankings were created by country ( rather than globally ) then categorized ( seen always seems to be the magic number ), it works fairly well, without any reliance on arbitrary population count boundaries and nomenclature ( village, city, etc. ) based on a single European country and language. Michael Patrick Data Ferret
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