Defines rural and urban areas based on population density

This function defines urban areas as those with a population density higher than rururb_cutoff per pixel. Urban areas are also contiguous and have a minimal total population equal to min_urbsize. The methodology is derived from http://documents.worldbank.org/curated/en/709121516634280180/pdf/122880-V1-WP-P156561-OUO-9-FINAL-ENGLISH.pdf

DefineUrban(population.raster, rururb_cutoff = 300, min_urbsize = 2000)

Arguments

population.raster

raster map containing population densities

rururb_cutoff

minimal population density to define an urban area

min_urbsize

minimal total population size to define an urban area

Value

a raster similar to population.raster in which all non-urban pixels are masked (i.e. NA)