Lake Chad

Lake Chad lies in west central Africa, bordering the countries of Nigeria, Cameroon, Chad, and Niger. With a maximum surface area of 2,500 square kilometers—approximately the size of Rhode Island—Lake Chad is the fourth-largest lake on the African continent. Lake Chad is located in a semiarid portion of Africa called the Sahel, known for its bipolar wet and dry seasons. Freshwater supplies from the lake provide sustenance for 8.5 million farmers, fishermen, and cattle herders in the region.

Lake Chad is fed primarily by two rivers originating farther south in the mountainous Central African Republic: the Chari and Logone. The size of the lake varies with the seasons. During the wet season (July- September), Lake Chad receives roughly 38 centimeters of rainfall. The dry season (October-June) is characterized by minimal rainfall and leads to frequent droughts. The northern region of Lake Chad, which straddles an arid climate zone, often receives only half the amount of rainfall as southern Lake Chad.

Lake Chad is shallow compared with most African lakes - only seven meters at its deepest spot—and therefore evaporation during the dry season has a significant impact on lake recession and total surface area.

The severity of recent droughts in the region has contributed to a rapid shrinkage of Lake Chad in the past forty years. Since 1960, Lake Chad has shrunk from 25,000 square kilometers to to its present size, one-tenth the 1960 size. This arises from a combination of factors, including uncharacteristically long dry seasons and the migration of large numbers of people to the area.

In the past, Lake Chad occupied a much larger land area than it does today. Climatologists and hydrologists have divided the climate history of Lake Chad into three eras: Paleo-Chad, Mega-Chad, and present- day Lake Chad. Approximately 55,000 years ago, Paleo-Chad occupied a swath of land with an estimated surface area of 2 million square kilometers.

This surface area would comprise the entire northeastern portion of present-day Africa, from Egypt to Nigeria. Between approximately 20,000 все and 3000 все, the Paleo-Chad Basin underwent multiple periods of aridity and the lake recessed to form Mega-Chad, which was only a quarter the size of Paleo-Chad. Like Paleo-Chad, Mega-Chad faced severe climatic conditions over time and shrank decade by decade. Climatologists believe Mega-Chad shrank significantly as a result of the increasing effects of the harmattan, a seasonal dry wind from the Sahara that has contributed to seasonal droughts in the region.

The era of Lake Chad began around 0 се. In the course of the past two thousand years, Lake Chad has completely dried up on six occasions. In 1908, a severe drought created the Great Barrier, a ridge that has since divided Lake Chad into a northern and southern basin. Up until 1908 the ridge was only visible during the dry season. Two other drought spells from 1973 to 1974 and from 1984 to 1985 forced the lake to recede and caused widespread famine in the region.

Since so many people derive their livelihoods from Lake Chad, governments from the bordering African nations have developed large-scale irrigation and water conservation projects, utilizing diminishing water supplies to develop national agricultural schemes and supplying expanding rural populations with adequate water supplies.

The rapid shrinkage of Lake Chad has exacerbated problems for small-scale sedentary farmers and pastoralists in the immediate Lake Chad basin region. Large-scale irrigation projects, such as the South Chad Irrigation Project (SCIP), have proceeded (and subsequently failed) regardless of the two shrinkage periods.

These projects certainly had political motivations, the primary of which being the perceived need for self-sustainability in terms of food production, relying less on agricultural imports from other West African countries. These import substitution schemes arrived before the export oriented schemes of structural adjustment programs (SAPs) of the World Bank and IMF in the 1980s.

Failure of these large-scale irrigation schemes resulted from lack of infrastructure support from the goverment and high failure rates at the community level, where people were used to their own methods of coping with diminishing water resources. Recently, neighboring countries have continued to implement programs for water resource management, but with more grassroots participation in the design process.