Earth-observing Landsat satellites have been capturing images of the planet’s surface since 1972. Landsat 8, the newest satellite in the joint NASA and U.S. Geological Survey program, was launched Feb. 11, 2013, and now collects more than 400 images per day.
New and archived Landsat data are available free to the public from USGS.
Researchers put the free data to a multitude of uses. One is called the National Urban Change Indicator, or NUCI, a product developed by MDA, a company that makes geo-spatial products derived from satellites.
Using satellite imagery, NUCI detects if an area has undergone a human-induced change over a 25-year period.
Urbanization can spell trouble for flood risk. Soil typically acts like a sponge, absorbing water from rainfall. When soil is covered with concrete or other impermeable material, water has nowhere to flow except towards storms and rivers, thereby increasing flood risk.
For more information on this, visit http://www.nasa.gov/earthrightnow