^{Guinea has a relatively dense hydrographic network with 1161 rivers inventoried and whose basin areas vary from 5 km 2 to 99,168 km 2 (Niger).}

This network is characterized by the irregularity of the regime and the international nature of 13 of these rivers that irrigate most West African territories.

Guinea's hydrographic network consists of two types of watercourses:

• Rivers in mountainous regions: made up of torrents, waterfalls, waterfalls, lakes, lakes, ponds, swamps and ponds (Middle Guinea, Guinea Forestale);
• Rivers in flat regions: made up of meanders, lakes, lakes, ponds, ponds (Upper Guinea) and deltas (Lower Guinea). These rivers are deeper than those in mountainous regions and have a larger major bed and are richer in aquatic fauna and flora.

From an ecosystem point of view, these environments are distinguished into lotic ecosystems and lentic ecosystems.

 

In Lower Guinea

• Lentic ecosystems: in coastal areas, floodplains and ponds are generally associated with estuaries and mangroves. These ecosystems are the subject of intense economic activities.

 

• Lotic ecosystems: they are mostly regular streams due to heavy rainfall and the very flat topography of the coastal region. However, in its part which adjoins Foutah Djallon in its foothills, the rivers sometimes have a torrential regime due to the steep slope and the rocky bottoms.

The most important rivers are: The Coliba, the Kogon, the Tinguilinta, the Tinguilinta, the Fatala, the Konkouré, the Soumba, the Kolenta, and the Forcariah.

 

In Middle Guinea:

• Lentic ecosystems: they consist of hydromorphic plains that are quite rare except for those located in the Koliba basin in the North-West of Koundara prefecture.

There are a few lakes and perennial pools in Tougué Prefecture. These sites are traditional fishing grounds par excellence and areas of attraction for animals.

 

• Lotic ecosystems: they consist mainly of Bafing and Gambia.

 

In Upper Guinea:

• Lentic ecosystems: the region's mild relief and its hydrography make it a vast alluvial plain in the middle of which large rivers meander.

The numerous large pools and floodplains that border the rivers extend on average over areas of 2 to 4 km2.

 

• Lotic ecosystems: they consist of the Bafing, the Bakoye and the Niger Basin whose main tributaries are Mafou, Niandan, Milo, Tinkisso, Dion, Bakoye and the Niger Basin, whose main tributaries are Mafou, Niandan, Milo, Tinkisso, Dion, Dion, Sankarani and Fié. Together, they total about 2,500 km of waterways.

 

In forest Guinea:

• Lentic ecosystems: they are made up of numerous and very small pools of less than one hectare (wintering pond at an altitude of 1400 m at Mount Nimba, Samoe pond in N'zérékoré).

 

• Lotic ecosystems: they are made up of Cavally, Mano, Diani, Loffa and Makona.