Lake Chad (Arabic: بحيرة تشاد, Kanuri: Sádǝ, French: Lac Tchad) is an endorheic freshwater lake located at the junction of four countries: Nigeria, Niger, Chad, and Cameroon, in western and central Africa respectively, with a catchment area in excess of 1,000,000 km2 (390,000 sq mi).

The lakeside is rich in reeds and swamps, and the plain along the lake is fertile, making it an important irrigated agricultural area.

The lake is rich in aquatic resources and is one of the important freshwater fish producing areas in Africa.

However, due to climate change and human water diversion, it has shrunk significantly since the mid-1970s, and its area has fluctuated between 2,000 and 5,000 km2 (770 and 1,930 sq mi).

One of the oldest domesticated Pearl millet in West Africa was found in the Chad Basin, charred together with wild grasses, and their era can be traced back to 800–1000 cal BC.

[14] Permanent villages were established to the south of the lake by 500 BC,[15] and major archaeological discoveries include the Sao civilization.

[17] After the Arabs conquered North Africa during the 7th and 8th centuries, the Chad Basin became increasingly linked to the Muslim countries.

At the beginning of the founding of the country, the Kanem people continued to live a nomadic life until the 11th century, when they were Islamized and settled in Njimi.

In the second half of the 16th century, the Bornu Empire began importing firearms from North Africa, consolidating its military hegemony.

By the second decade of the 20th century, Lake Chad had been colonized and occupied by Britain, France, and Germany, defining boundaries that are largely intact with the present post-colonial states.

[19][20] At the beginning of independence, the countries surrounding Lake Chad not only had a poor economic foundation, but also had more complex ethnic, religious, and political conflicts.

[25] The climate of the Lake Chad region is strongly influenced by continental and maritime air masses.

[5][7] The Chad Basin covers an area of about 1×10^6 km2 (390,000 sq mi), and is injected by the Chari, Logone, and Yobe Rivers.

It was thought to be related to vegetation loss, global warming, and sea surface temperature anomalies.

Reeds mainly grow in the north where the salinity is high, and the floating plant pistia sometimes covers large areas of open water.

[35] The surrounding dense woodland has been converted to open forest with acacias, baobabs, palms and Indian jujube.

[36] It is permanently or seasonally inhabited by hundreds of species of birds such as northern shoveler, Egyptian goose and marabou stork.

There are more than 70 ethnic groups around the lake, most of whom are distributed on the south bank, where the population density exceeds 100/km2 (260/sq mi).

They rely on the water source of Chad Lake for irrigation, breeding, animal husbandry and drinking.

The collection of forest products such as gum arabic, honey, beeswax, and firewood is of great significance in the region.

Cattle are the most important livestock raised, as well as poultry, goats, sheep, camels, horses, and donkeys.

[5] Fishing has traditionally been the most important economic activity for the people of the lake area, which almost ceased during drought periods and only resumed in the mid-1990s.

[26] The dams built on the upper reaches of the rivers entering the lake changed the time and scope of seasonal floods and disrupted the migration of fish, resulting in a sharp reduction in the populations of Alestes baremoze and Nile perch, the main catches of Lake Chad, and a significant reduction in the catch.

The four countries along the lake are all facing the problem of extreme poverty, and due to the difficulty in meeting their livelihoods, some local residents have been involved in drug and arms trade.

[26] This has been exacerbated by the activity of Boko Haram, an insurgency that has displaced millions of people and disrupted development through the region.

[43] The surrounding countries' water replenishment plan for Lake Chad includes the construction of a 2,400 km (1,500 mi) canal to transport 100×10^9 m3 (130×10^9 cu yd) of water from the Congo River Basin to the Chari River Basin every year, and use a series of dams along the route to generate electricity.