The Desert Laboratory Repeat Photography Collection - An Invaluable Archive Documenting Landscape Change

The Desert Laboratory Repeat Photography Collection, the largest collection of its kind in the world, is housed at the U.S. Geological Survey (USGS) in Tucson, Arizona. The collection preserves thousands of photos taken precisely in the same places but at different times. This archive of 'repeat photographs' documents changes in the desert landscape and vegetation of the American Southwest, and also includes images from northwestern Mexico and Kenya. These images are an invaluable asset to help understand the effects of climate variation and land-use practices on arid and semiarid environments.