File:land-usage2.png: Difference between revisions

Summary

The 3 main land uses - crop land, pasture land, built-up land - shown in 3 overlapping colors.

Yellowish-orange is crop land.

Cyanish-blue is pasture land.

Magenta is built-up land (housing & cities) (which may be hard to see outside of India & China).

These colors act like inks, which when overlap, create mixed colors.

Image generator code:

pop  << data/population.data-float64-8640x4320 # population counts
crop << data/cropland.data-float32-4320x2160   # cropland fraction of land
past << data/pasture.data-float32-4320x2160    # pasture fraction of land
earth<< data/continents-black-on-white.png     # base layer 8640x4320

# convert the data and shrink down to 4320x2160
pop @@ quantity_to_density # convert to 'people per km^2'
pop /= 2500                # threshold for land to be considered 'fully built-up'
pop @@ width/2
pop @@ height/2
crop >= 0
past >= 0
earth *= -0.07
earth += 1
earth @@ width/2
earth @@ height/2

# make image
out.r := earth
out.r -= past
out.r @@ 01
out.b := earth
out.b -= crop
out.b @@ 01
past *= 0.25
crop *= 0.25
out.g := earth
out.g -= past
out.g -= crop
out.g -= pop
out.g @@ 01
out >> data/land-usage2.png

See also: File:land-usage1.png