File:land-builtup1.png: Difference between revisions

Summary

Map of Earth with all built-up land shown in black.

Made from File:population.data-float64-8640x4320 and File:blue-marble-posterized.png.

Image generator code:

pop << data/population.data-float64-8640x4320 # population counts
earth << data/blue-marble-posterized.png      # base layer

pop @@ quantity_to_density # converts population counts to density (people per km^2)
pop /= 2500 # threshold (people per km^2) for land to be considered "fully built-up"
pop <= 1
pop :: earth.r # resize to fit base layer

earth.r -= pop
earth.g -= pop
earth.b -= pop
earth.r @@ 01
earth.g @@ 01
earth.b @@ 01
earth >> data/land-builtup1.png

Note: we are using population density as a best guess for determining which land is built-up. In theory that might not be perfectly accurate, but in practice, the end result is matches well enough with totals from other data sources.

See also

• File:land-crop1.png - crop land
• File:land-pasture1.png - pasture
• File:land-usage1.png - all land usage
• File:land-wild1.png - untouched lands