English: On January 16, 2017, the Moderate Resolution Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured a true-color image of Lake Chad.

Lake Chad sits in mostly in the country of Chad, which fills the east side of this image. The other countries visible, moving clockwise from Chad, are Cameroon, Nigeria, and Niger.

Once an extremely expansive, lake, Lake Chad is now Africa’s fourth largest lake. Drought and increasing irrigation have shrunk Chad dramatically, with the result that it is only a fraction of its former size. It is also very shallow, reaching only about 34 feet (10.5 m) at its deepest point.

The Chari River brings roughly 90% of the water into the lake, with the Yobe River and rainfall contributing the remaining inflow. There is no outflow other than evaporation and percolation into the soil. The lake is surrounded by marshes.

The Lake Chad basin supports a rapidly growing population, currently about 17 million people. Despite the fresh water found in Lake Chad, many of these people lack access to safe drinking water and proper sanitation. According to ReliefWeb, the Chad Basin is in crisis due to the “combined impact of deepening insecurity, rapid population growth and severe vulnerability resulting from the effects of climate change, environmental degradation, poverty and underinvestment in social services is translating into record numbers of people in need of emergency relief.”