State of Flux

Each week State of Flux features images of different locations on planet Earth, showing change over time periods ranging from centuries to days. Some of these effects are related to climate change, some are not. Some document the effects of urbanization, or the ravage of natural hazards such as fires and floods. All show our planet in a state of flux. Ichkeul Lake in northern Tunisia. Top: November 14, 2001. Bottom: July 29, 2005; the water level is higher, but a large part of the lake appears red due to the presence of aquatic plants. Avian stopover, Tunisia Ichkeul Lake and wetland are a major stopover point for hundreds of thousands of migrating birds who come to feed and nest. It is the last remaining lake in a chain that once extended across North Africa, and has badly deteriorated as a result of the construction of three dams on rivers supplying it and its marshes. The dams have cut off almost all inflow of freshwater, causing the salinity of the lake and marshes to rise, and a sharp reduction in the migratory bird populations dependent on the habitat the lake formerly provided. The Tunisian government plans to undertake various measures to retain freshwater in the lake on a year-round basis and reduce the salinity of the lake. Credit: Courtesy of NASA/GSFC/METI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team. Caption adapted from the ASTER gallery.