|This satellite image depicts the Mississippi Delta in 1985 before major storm damage of the past 25 years. Landsat TM band 4 (near-infrared), which is particularly sensitive to emergent vegetation (light gray) and water (black). Compare with images below; processing by J.S. Aber.|
The following satellite images display the Mississippi Delta in 2004, one year before Hurricane Katrina, and in 2005 about two weeks after the hurricane. Slide the vertical bar back and forth or simply click anywhere on the image to see the dramatic changes in vegetation and land areas.
As this simple example demonstrates, the before-and-after visualization technique is a powerful means to portray geospatial information. In this case, temporal changes in land cover, namely vegetation and water, are displayed for co-registered Landsat images, so that differences are quickly apparent.
Return to Geospatial Analysis at Emporia State University.
Text and imagery © J.S. Aber (2017).