Lake Chad is a historically large, shallow,
endorheic lake in
Africa, which has varied in size over the centuries. According to the
Global Resource Information Database of the
United Nations Environment Programme, it shrank as much as 95 rom about 1963 to 1998, but "the 2007 (satellite) image shows significant improvement over previous years." Lake Chad is economically important, providing
water to more than 68 million people living in the four countries surrounding it (
Chad,
Cameroon,
Niger, and
Nigeria) on the edge of the
Sahara Desert. It is the largest lake in the
Chad Basin.