Once a great lake close in surface area to North Americas Lake Erie, Africas Lake Chad is now a ghost of its former self. According to a study by University of WisconsinMadison researchers, working with NASAs Earth Observing System program, the lake is now 1/20th of the size it was 35 years ago. The decrease is due to climate change (the region has suffered from a significant decline in rainfall since the early 1960s) and human demand for water (Lake Chad has been the source of water for massive irrigation projects).
The most dramatic decrease in the size of the lake is shown in the fifteen years between January 1973 (left) and January 1987 (right). Beginning in 1983 the amount of water used for irrigation began to increase. Ultimately, between 1983 and 1994, the amount of water diverted for purposes of irrigation quadrupled from the amount used in the previous 25 years. The red color denotes vegetation on the lake bed and the ripples on the western edge of the lake denote sand dunes formed by the wind.