The low contrast relief
Its geological history merges 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 a Precambrian basement, except for the coast, which is occupied by formations of the sedimentary basin. The relief of Côte d'Ivoire could therefore be summed up as the "triumph of horizontality".
There are, however, three main types of relief. The southern part of the country has the general appearance of a plain, consisting of a moutonnement of small, low hills. The north, a succession of several plateaus of two hundred to five hundred metres in altitude, is characteristic of this overall flatness of the landscape. The monotony of these two types of horizons is broken by the presence of isolated reliefs in the form of alignments of hills, tabular mounds or granite domes. The soils are often loose, reddish in colour, ranging from ochre to rust.
The mountains of Man
Only the west and north-west of the country, which constitute the eastern end of a mountainous region, the Guinean ridge that ensures the extension of the Fouta-Djalon mountains, are distinguished by a more contrasted relief and the presence of peaks of more than 1,000 metres in altitude. The region of the Eighteen Mountains around the city of Man concentrates the country's peaks, where the Yacoubas live. The highest point, Mount Nimba, rises to 1,752 metres. It is located on the triple border between Côte d'Ivoire, Guinea and Liberia, and is part of the eponymous reserve classified as a biosphere reserve and UNESCO World Heritage Site. In its extension, there is Mount Richard-Molard (about 1,280 metres above sea level). There is also the famous Mount Tonkpi or Tonkoui (which means big mountain in Yacouba), which 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 important water supplies, but the seasonal irregularity is great. The lagoons punctuate the Ivorian coastline in the eponymous region, shaping the landscape
The Comoé River. 900 km long, this immense river takes its source in Burkina Faso and flows from north to south to flow into the ocean at Grand-Bassam. Queen Pokou is said to have thrown her son into the river to save her people when she crossed it
The BandamaRiver . It stretches over 950 km and is entirely Ivorian. It crosses the country in its middle and flows into the Atlantic Ocean at Grand-Lahou. The delta of the river 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, the N'Zi, the Tiemba, the Bafing, the Lobo and the Davo.
The SassandraRiver . 650 km long, it originates in Guinea and reaches 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 department of Meagui, which is currently under construction.
The Cavally River . The Cavally River is 515 km long and has its source in the northern Nimba Mountains on the Guinea side. It serves as a natural border with Liberia all along the border. It supplies water to the surrounding Taï primary forest and emerges 21 km east of Harper, Liberia. Its name comes from the name of some of the fish found at its mouth.
Lake Kossou. This artificial lake, 150 km long, was formed to build the Kossou dam between 1969 and 1978 on Baule land, not far from Yamoussoukro, during the Houphouët era. It allowed the irrigation of 50,000 hectares of land, but it also cost the displacement of nearly 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 tons. However, many have given up fishing to devote themselves to coffee and cocoa plantations thanks to the possibility of irrigation.
Lake Buyo. Like Lake Kossou, this artificial lake was created to build the Buyo dam on the Sassandra River from the 1970s to 1980s. It is located just above the Taï forest, not far from Daloa. It required the engulfment of 900 km², the displacement of nearly 22,000 people, the region was not heavily populated, of Bébé and Kouzié, joined later by Akan, Krou, Mandé.
The lagoon region. The lagoons in Côte d'Ivoire are concentrated on 60% of the coastline and occupy about 1,200 km² over nearly 350 km. The lagoon region spreads out around Abidjan. From east to west, they are: Ehi, Tendo, Aby, Kodouobé, Ouladine, Potou, Adjin, Ono, Aghien, Ebrié, Makey, Tiagba, Brigna, Niouzoumou. The Ebrié Lagoon is the most important. Further towards Assinie, the Ehotilé lagoon is also one of the most important, whose eponymous national park is classified by UNESCO. The main lagoons are connected by the Assinie and Asagny canals, dug in the 1950s. It is therefore possible to travel by lagoon between Assinie and Grand-Lahou for about 40 km! They are home to many sedentary and migratory birds, and support traditional fishing communities. The edges of the lagoon are swampy, consisting of mangrove, while the waters are brackish.
Ebrié Lagoon. Also called Ahizi lagoon, it stretches over 130 km long, with a maximum width of 7 km, covering an area of 560 km². It is connected to the ocean by the Vidri canal to allow the opening of the port of Abidjan on 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 connected to the Bandama and the Grand-Lahou lagoon by the Asagni canal. It is the largest of the region, which bathes Abidjan (more exactly the districts of Treichville, Marcory and Koumassi), Grand-Bassam, Bingerville and Dabou. It also includes the Boulay, Vitré, Désirée and Morin islands.
