File:land-usage2.png: Difference between revisions

File:land-usage2.png (view source)

1,171 bytes added , 1 September 2022

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 == 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.
+[[Code:isochromic.c|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                # [[land/built-up|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]]