manila by night

Google Earth has released several new layers, among them NASA sourced content including Earth By Night.

Seeing the human generated lights on the night time hemispheres is not only beautiful, but they also reveal the urbanization patterns across the landscape. (They also show how much light pollution we generate.) The screencap above shows how the megamanila urbanized region stretches from Clark in the North to Batangas City in the South along very strong corridors. It also shows the Metro Manila westward to reach Subic. You can also see how the corridor between the shores of the Laguna de Bai and Taal Lake are rapidly urbanizing -and will soon approximate the density you see between the Manila Bay and Laguna lake.

Additional images from Google reveal how Naga City is growing into Legaspi City. This one shows the cities of Cebu, Bacolod, and Iloilo. And this one Davao and GenSan.

With a little map algebra, you could deduce the relative density levels between those urbanized areas using the images. With a time sequence, you could also show the direction and intensity of the pace of urbanization.