Terrain shapes and bedrock
According to COUNTRYAAH, the whole of Guinea-Bissau except the part bordering Guinea is lowland. The coastal area is crossed by a large number of river valleys that give rise to a very lush coastal type, riak coast. Large parts of the coast are sometimes waterlogged, and mangrove swamps and marshlands are common. The Bijagos Islands just off the coastline are isolated parts of this plain.
The inner plains, which spread to the north, form a smooth and monotonous topographic region. They consist, in the northwest, of a southern part of the Senegal river basin, and partly of the Gabú plain in the northeastern part of the country, which is drained by the rivers Geba and Cacheu and their tributaries. The slight slope of their race allows them to meander over the ground and float over their boards during the rainy season.
The northeastern highlands are made up of outcrops from the sandstone plateau Fouta Djallon in Guinea, which reaches about 200 m above sea level. The Boe Hills spread between the western parts of Fouta Djallon and the Gabú plain. They have deep degraded valleys between flat-topped laterite clad elevations.
Guinea-Bissau is characterized by a hot and humid climate. Along the coast, a monsoon climate type rains with rainy season in May – October and with a rainfall of 1,000–2,500 mm per year. The interior of the country has tropical savannah climate with greater variation in temperature and rainfall. In the plains, 1,500-1,800 mm per year falls and in the highlands less than 1 300 mm; Drying times occur between November and April. The temperature is high everywhere, on average 26-27 °C.
Plant-and animal life
The natural vegetation in the southern coastal region is partly deciduous rainforest (in particular the islands still have some such remains) and in the north as well as inland by tree water. Nowadays large parts have been replaced with more open savannas or cultivated land and palm plantations. Along the coasts and estuaries there is mangrove swamp with red mangrove.
Wildlife is depleted, but the red baboon (Paʹpio paʹpio), green markata, red colobus monkey (Procoʹlobus baʹdius), house monkey, spotted hyena, several species of antelope and squirrels are still widespread. For the birds often seen among Reed Cormorant (Phalacro’corax africa’nus), hooded vulture (Necrosy’rtes mo’nachus), Black Kite, palm-nut vulture, rose-ringed parakeet, Ethiopian Roller (Cora’cias abyssi’nicus), Pied Kingfisher, Green Bee-eater, common bulbul, pied crow (Co’rvus a’lbus) and various sunbirds. Common agam is one of the most commonly seen lizards both in villages and on savannas.
Just over 10% of Guinea-Bissau’s land area is under some form of nature protection. In 2011, the country had two national parks, both created in 2000.