Investigating the rank-size relationship of urban areas using land cover maps

We investigated the possibility that the rank-size rule can be applied to the relationship between urban size and rank order. Accordingly, using a global land cover data set, we clustered contiguous urban grid cells, calculated the area in each cluster, and ranked urban areas in each of the countries studied. This research revealed that Zipf's law can be applied to the relationship between urban area and rank order as well as to city populations. Comparisons were made in some countries, and it was shown that the urban area rank-size rule was free from administrative boundaries. Finally, in Japan, using land-use maps for several times in recent history, changes in rank-size were investigated. As a result, it was found that the slopes for urban areas did not change vis-à-vis their rank in a double logarithmic graph and that only the x and y interception changed.