The Republic of Chad, located in north central Africa, is bounded on the north by Libya, on the east by Sudan, on the south by the Central African Republic and on the west by Cameroon, Nigeria, and Niger. It has an area of 1 284 000 km2 and lies between latitudes 8° and 24° N and longitudes 14° and 24° E, stretching 1 700 km from north to south. A landlocked country, it is separated from Doula by 1 500 km, from the ports of Nigeria by 2 500 km, and from Pointe-Noire, via the Central African Republic, by some 3 000 km.
Chad's terrain is dominated by the low-lying Chad Basin (elevation about 250 m), which rises gradually to mountains and plateaux on the north, east, and south. In the east, heights of more than 900 m are attained in the Ennedi and Ouaddaï plateaux. The greatest elevations are reached in the Tibesti massif in the north, with a maximum height of 3415 m at Emi Koussi. The northern half of the republic lies in the Sahara and is rocky, arid desert. A flat stretch of savannah (grassland with scattered trees) in central Chad separates the vast desert in the north from a small, extremely fertile region in the south. The only important rivers, the Logone and Chari (Shari), are located in the south-west and flow into Lake Chad. The lake doubles in size during the rainy season.
Chad has the following climatic zones:
- A Sudano-Guinean climate in the south with annual rainfall of over 950 mm, a rainy season of six to seven months (MayNovember), an average annual temperature at Sarh (formerly Fort Archambault) of 28° C (absolute minimum 10° C, absolute maximum 45° C) and an annual Piche-recorded evaporation of 2 027 mm in 1961;
- A Sahelo-Sudanian climate with an annual rainfall of 500 to 950 mm, a rainy season of four to five months (May/JuneNovember), an average annual temperature at N'Djamena of 28° C (absolute minimum 8° C, absolute maximum 47° C) and an annual Piche-recorded evaporation of 3 222 mm in 1961;
- A Sahelo-Saharan climate with an annual rainfall of 200 to 500 mm, a rainy season of three months (JulySeptember), an average annual temperature at Abéché of 28° C (absolute minimum 8° C, absolute maximum 49° C) and an annual Piche-recorded evaporation of 4 465 mm in 19591961;
- A Saharan climate with an annual rainfall of under 200 mm, a rainy season of two months (JulyAugust) with some scattered rain in May, June and September, an average annual temperature at Faya-Largeau of 28° C (absolute minimum 4° C, absolute maximum 49° C) and an annual Piche-recorded evaporation of 6 420 mm in 1961.
These climatic zones lie in eastwest bands across the country moving northward, as the altitude rises with the central Chad and Ouddai mountain massifs.
Soils in the Chad basin - which in recent geologic history was covered by huge lakes - are mainly clay or sandy. The developing soils have undergone various formative processes, leading to ferralitic and leached tropical ferruginous soils, particularly in the south.
The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.