Bodélé Depression (Nigeria, February 2004).At the southern edge of the Sahara Desert, theBodélé Depr

Bodélé Depression (Nigeria, February 2004).At the southern edge of the Sahara Desert, theBodélé Depression used to be part of the floor of a much largerLake Chad, but it is now slowly being transformed into a desertlandscape.  In the mid-1960s, Lake Chad was about the size of LakeErie.  Since then, persistent drought conditions, along withincreased demand for freshwater for irrigation, have reduced the laketo about 5% of its former size.As the waters receded, the silts and sediments onthe lakebed were left to dry in the hot sun.  The small grains ofsilty sand are easily swept up by strong gusts of wind thatoccasionally blow over the region.  Once aloft, dust from the BodéléDepression can be carried for hundreds, even thousands, ofkilometres.Lake Chad is the olive-green part surrounded bythe tan and light brown colours of the surrounding landcape, whereChad, Niger, Nigeria and Cameroon share borders. -- source link

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