The terrain of Chad

Chad

Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

 in central Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 is dominated by the low-lying Chad Basin (elevation about 250 m / 820 ft), which rises gradually to mountains and plateaus on the north, east, and south. In the east

East

East is a noun, adjective, or adverb indicating direction or geography.East is one of the four cardinal directions or compass points. It is the opposite of west and is perpendicular to north and south.By convention, the right side of a map is east....

 heights of more than 900 metres (3,000 ft) are attained in the Ennedi and Ouaddaï

Ouaddaï

Ouaddaï may refer to:* Ouaddaï Prefecture* Ouaddaï Region* Ouaddai Empire* Ouaddai plateau*Ouaddaï highlands...

 plateaus. The greatest elevation

Elevation

The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

s are reached in the Tibesti massif in the north, with a maximum height of 3,415 metres (11,204 ft) at Emi Koussi. The northern half of the republic lies in the Sahara

Sahara

The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...

. The only important rivers, the Logone and Chari

Chari River

The Chari or Shari River is a 949-kilometer-long river of central Africa. It flows from the Central African Republic through Chad into Lake Chad, following the Cameroon border from N'Djamena, where it joins the Logone River waters....

, are located in the southwest and flow into Lake Chad

Lake Chad

Lake Chad is a historically large, shallow, endorheic lake in Africa, whose size has varied over the centuries. According to the Global Resource Information Database of the United Nations Environment Programme, it shrank as much as 95% from about 1963 to 1998; yet it also states that "the 2007 ...

. The lake doubles in size during the rainy season.