Visualizations by
Alex Kekesi
Released on June 30, 2013
One of the many ways to keep FEMA maps up to date is by tracking urban change using satellite imagery. Take this suburb of Atlanta, Georgia as an example. By mining Landsat images spanning a 27 year period, it's possible to identify areas where the land surface has permanently changed and affect the areas ability to absorb water.
The river to the Northwest is the Chattahoochee River. The "Y"-shaped roads are Interstate 85 (upper branch) and Route 316 (lower branch). As the years go by, one can see the Mall of Georgia being built in the upper middle part of the screen, immediately north of Interstate 85. Surrounding neighborhoods sprout up throughout this whole area as we move through time.
This animation was created for use in a NASA video on water run-off changes related to urban sprawl titled "FEMA Risk Map".
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0