Terrain shapes and bedrock
According to COUNTRYAAH, the nature of Equatorial Guinea is similar to that of Gabon and western Cameroon. The mainland part of Equatorial Guinea, Mbini, has in the far west a coastal plain, which turns into an area with hills. Further east, the inland plateau (mesetan) extends with altitude ridges radiating from the Crystal Mountains of Gabon. The bedrock in the interior is mostly Precambrian granite, while the coastal plain is made up of young, sedimentary formations. Soils are meager due to leaching and erosion.
The Utamboni River in the south flows into a large estuary that forms the mouth of a number of rivers, including from Gabon. The northern part of the country is drained by Benito, which forms several waterfalls in the middle of the country, and Ntem in the far north, which forms part of the border with Cameroon. None of the rivers are navigable more than a distance of 70-80 km in the lower part. The coast is low and sandy except at the far south, where there are low cliffs, and the country therefore lacks natural ports.
Of the five islands that are also part of Equatorial Guinea, the two major ones, Bioko and Annobón, are volcanic formations. Bioko in the north is the largest and is really a continuation to the southwest of the high Cameroon mountains. Here are a number of volcanoes and crater lakes. Santa Isabel, a extinguished volcano, rises to 3,008 meters above sea level. A number of waterfalls are used for energy generation. Especially the southern coastline is very steep and dangerous for sailing vessels. Annobón consists of a number of lower volcanic peaks, the highest, Monte de Santa Mina, reaching 750 m above sea level.
The mainland part of Equatorial Guinea has a tropical equatorial climate. The average temperature is around 26 °C, and the relative humidity is 86% on average and up to 94% in exceptional cases. Rainy periods occur in February – June and September – December, and the amount of precipitation on the coast amounts to 2,400 mm per year in the north and 4,500 mm in the south. In the hinterland, about 1,500 mm per year falls.
The island of Bioko has a particularly stressful and unhealthy climate, mainly due to the high humidity. The annual average temperature is 25 °C with a maximum temperature of 34 °C on average and a minimum temperature of 17 °C. Drying times occur during November to March, but the sky is mostly covered by clouds. In the south the monsoon winds bring in even more humid air, and the rainfall here can rise to 11 250 mm per year.
Plant-and animal life
The country’s natural vegetation consists of tropical rainforest. There are several common trees that are economically sought after, for example. ebony trees, African mahogany (species of the Khaya genus in the mahogany family) and species in the genus Sideroxylon (the family sapotyledon). The richest parts were formerly the humid lowland area closest to the coast, but today much of the natural vegetation in this region has been harvested and replaced with plantations (oil palm and cocoa) and agriculture. Forests are still relatively intact in the interior, higher parts of the country and on the island of Bioko. There are also lush and mossy mountain rain forests with tree fronds.
The land was previously rich in many larger forest animals, but hunting has greatly reduced the game. Chimpanzee, lowland gorilla, mandrill, drill, devil monkey (Coʹlobus saʹtanas), leopard, African elephant, bush boar, forest pig, hippopotamus, several species of forest antelope and African buffalo are all native to Equatorial Guinea. Typical bird groups in the country are kingfishers, turacos, rhinoceros, sunbirds and weavers. The parrot gray jako is still common. Nile crocodile was formerly common but has been reduced to small populations by hunting. The forests show great wealth of frogs (especially the family western tree frogs) and chameleons. The well-camouflaged and highly toxic gab worm is one of the most beautiful snakes in the woods.
Equatorial Guinea had three national parks in 2010, one of them on the island of Bioko.