The low contrast relief
Its geological history is intertwined with that of the West African craton, the "old African platform", with some rocks dating back three billion years.
Almost all of Côte d'Ivoire is covered by Precambrian bedrock, except for the coast, which is occupied by sedimentary basin formations. The relief of Côte d'Ivoire could therefore be summed up as the "triumph of horizontality".
However, there are three main types of relief. The south of the country has the general appearance of a plain, consisting in fact of a series of small, low hills. The north, with its succession of plateaus ranging in altitude from two to five hundred meters, is characteristic of this overall flatness of the landscape. The monotony of these two horizons is broken by the presence of isolated reliefs in the form of alignments of hills, tabular knolls or granite domes. Soils are often loose and reddish, ranging from ochre to rust.
The mountains of Man
Only the western and north-western parts of the country, which form the eastern end of a mountainous region known as the Guinean ridge that extends the Fouta-Djalon mountains, are characterized by a more contrasted relief and the presence of peaks over 1,000 meters high. The Dix-Huit Montagnes region around the town of Man concentrates the country's peaks, where the Yacoubas live. The highest peak, Mont Nimba, rises to 1,752 meters. It lies on the triple border between Côte d'Ivoire, Guinea and Liberia, and is part of an eponymous reserve classified as a biosphere reserve and UNESCO World Heritage Site. It is followed by Mont Richard-Molard (approx. 1,280 metres above sea level). The famous Mount Tonkpi or Tonkoui (which means "big mountain" in Yacouba) rises to 1,189 m.
Rivers, lakes and lagoons
Four major rivers irrigate the country from north to south. The hydrographic network, also made up of several small coastal rivers and a few tributaries of the Niger, provides very significant water supplies, but seasonal irregularity is high. Lagoons dot the Ivorian coastline in the eponymous region, shaping the landscape.
The ComoéRiver. 900 km long, this immense river rises in Burkina Faso, flows north-south and empties into the ocean at Grand-Bassam. Queen Pokou is said to have thrown her son into the river to save her people.
The BandamaRiver . Stretching 950 km, this river is entirely Ivorian. It crosses the middle of the country and empties into the Atlantic Ocean at Grand-Lahou. The river delta is particularly beautiful, and the meeting of river and ocean waters spectacular. In the center of the country, at Kossou, a dam has been built on the Bandama. Its main tributaries are the Marahoué, N'Zi, Tiemba, Bafing, Lobo and Davo rivers.
The SassandraRiver . 650 km long, it rises in Guinea and joins the ocean at Sassandra. The huge new Soubré hydroelectric complex was built by the Chinese and inaugurated in 2019 on this river, promising to double the country's energy capacity. Another dam project has been announced on the same river, in the Meagui department.
The CavallyRiver . The Cavally River is 515 km long and rises north of the Nimba Mountains on the Guinea side. It serves as a natural border with Liberia all along the border. It feeds the surrounding Taï rainforest and flows 21 km east of Harper, Liberia. Its name comes from the fish found at its mouth.
Lake Kossou. This 150 km-long artificial lake was formed to build the Kossou dam between 1969 and 1978 on Baoulé land, not far from Yamoussoukro, during the Houphouët era. The dam irrigated 50,000 hectares of land, but also displaced almost 100,000 inhabitants by covering 1,700 km² of land, including 200,000 hectares of forest - three times the size of Lake Geneva! Nearly 3,600 former farmers have become fishermen. Their production amounts to 20,000 tonnes. Many, however, have given up fishing to devote themselves to coffee and cocoa plantations, thanks to the possibility of irrigation.
Lake Buyo. Like Lac de Kossou, this artificial lake was created to build the Buyo dam on the Sassandra River between 1970 and 1980. It is located just above the Taï forest, not far from Daloa. The dam swallowed up 900 km² of land, displacing some 22,000 people. The region was not heavily populated by Bébé and Kouzié, later joined by Akan, Krou and Mandé.
The lagoon region. Côte d'Ivoire's lagoons are concentrated along 60% of its coastline, covering some 1,200 km² over nearly 350 km. The lagoon region extends around Abidjan. From east to west, they include: Ehi, Tendo, Aby, Kodouobé, Ouladine, Potou, Adjin, Ono, Aghien, Ebrié, Makey, Tiagba, Brigna, Niouzoumou. The Ebrié Lagoon is the largest. Further towards Assinie, the Ehotilé lagoon is also one of the most important, and its eponymous national park is a UNESCO World Heritage site. The main lagoons are linked by the Assinie and Asagny canals, dug in the 1950s. It is therefore possible to travel by lagoon between Assinie and Grand-Lahou for around 40 km! They are home to many sedentary and migratory birds, and support traditional fishing communities. The edges of the lagoon are marshy, with mangrove swamps and brackish waters.
Ébrié Lagoon. Also known as the Ahizi lagoon, this lagoon is 130 km long and up to 7 km wide, covering a surface area of 560 km². It is connected to the ocean via the Vidri canal, to enable the port of Abidjan to open up to the waters of the lagoon, but its natural connection was the estuary of the Comoé river, its major tributary, until it was blocked. It is linked to the Bandama and Grand-Lahou lagoons by the Asagni canal. It is the largest in the region, encompassing Abidjan (more precisely the districts of Treichville, Marcory and Koumassi), Grand-Bassam, Bingerville and Dabou. It also includes the Boulay, Vitré, Désirée and Morin islands.
