Geography of Sierra Leone

Sierra Leone is a small country on the western coast of Africa, with an approximately square shape, between parallels 7 and 10 N. Its limits are: Guinea to the north and northeast, Liberia to the east and south, and the Ocean Atlantic to the west and south.

Basic data

• Extension: 71,740 km2
• Border countries: Guinea and Liberia
• Highest mountain: Bintimani (1945 metres)

Relief and biogeography

Sierra Leone borders the Atlantic Ocean to the southwest. The country can be divided into four physical regions. The coast is about 400 km long, behind it is a flat belt of wetlands, between 8 and 50 km wide, which occupies 15 percent of the territory, made up of sand and clay, with numerous inlets and estuaries. conducive to Guinean-type mangroves. The exception is the Freetown peninsula, where the capital, Freetown, is located, and a forest-covered mountain range that reaches 880 m at Picket Hill.

The lands that follow the coast are plains and plateaus covered with forests, shrubs and cultivated lands. The plains occupy 43 percent of the country and range from 40 m in altitude in the west to 200 m in the east. Both in the coastal area and on the plains there are swampy areas known as bolilands, which flood in the rainy season and dry out in the dry season, allowing only grass to grow. In the northeast and southeast, the plateaus, 300 to 700 m high, with hills and escarpments, occupy 22 percent of the territory, reaching their highest altitude on the granite dome of Mount Bintumani, in the isolated Loma Mountains, with 1,945 m high, followed by the Tingi Mountains, which reach 1,853 m.

The northern region of the country is considered part of the tropical belt of the jungle and savannah mosaic of Guinea. In the Koinadugu district in the northwest are the Wara Wara Mountains, a collection of igneous and metamorphic rocks that jut out above a bush-covered environment. These mountains are the object of particular beliefs centered on the city of Kabala (Sierra Leone), where it is said that whoever wants to be the chief has to enter a certain cave, and also that women who want to get pregnant have to touch a stone brought from the mountains by an old woman. In 1960, a forest reserve was created in these mountains that has been reduced since then due to the advance of agriculture. The mountains reach 1000 m in height and are dominated by a forest savanna dominated by elephant grass, with gallery forests in the valleys.

Geology

The soils are granitic with a thin layer of laterite that gives it the characteristic reddish color. Sierra Leone can be divided into two major stratigraphic units. The eastern part belongs to the Precambrian craton of West Africa, consisting of highly metamorphosed rocks and granitic gneiss, including a visible layer of metamorphic rocks known as Kambui schists, in the mountains of the same name. The western part contains elements of an orogenic belt. called the Rokelides, which was deformed during the Pan-African thermal tectonic event, about 550 million years ago. The coastal belt is formed by recent Pleistocene sediments. The Rokelides thermal tectonic belt extends for about 600 km from Senegal, through Guinea and Sierra Leone along the coast to Liberia, and was formed as an aulacogen, an aperture basin formed within a plate oblique to the main trend of the West African fold belt. It consists of various types of gneiss and granites such as charnockite.

Climate

The climate is tropical, although it could be classified as a monsoon climate, but also as a transitional climate between equatorial climate and tropical savanna climate.

There are two seasons that determine the agricultural cycle: a rainy season from May to November, and a dry season from December to May, which includes the harmattan wind when dry winds blow from the Sahara desert and the temperature at night it drops to 19.oC. The average temperature is 27.oC and varies from 25.oC at 29.oC during the year.

The average rainfall is very high on the coast, in Freetown 2,945 mm falls in 152 days, but there is practically no rain between November and May, however in July and August it exceeds 700 mm with 27 days of rain each month. Temperatures hardly vary, with a slight cooling with heavy rains.

Rivers

In Sierra Leone there are five major river basins, flowing from northeast to southwest, and several smaller basins. From west to east, the Great Scarcies River (270 km, of which 40 km as the Kolenté River, in Guinea, and 101 km as a border between the two countries; the Little Scarcies River (280 km), also originates in Guinea, where It is called the Kaba River. the Rokel River (386 km), also known as Seli, flows into the Freetown Estuary, where it becomes the Sierra Leone River (40 km and a width of 6 to 16 km), with two major ports, Freetown and Pepel; the Jong River (249 km), also called Taia; the Sewa River (240 km, which joins the Waanje River before it flows and runs parallel to the coast towards the west to the Sherbro Strait, and the Moa River (425 km), which flows near Sulima. The Mano River rises in Liberia, but with its tributary, the Morro, it forms 145 km of border with Sierra Leone.

All of these rivers originate in the north of the country, near or in the mountains of Guinea, and flow into the Atlantic Ocean. Throughout their journey, some change their name several times. Almost all of them have intermittent rapids that do not allow them to be navigable.

Among the smaller rivers are the Lokko River, the Gbangbaia, the Rhibbi Thauka and the Sherbro.

Vegetation and fauna

The distribution of vegetation has been greatly influenced by human activity. The original forest cover survives only in the reserves of Mount Gola in the southeast, where there is a national park that borders Liberia. The original forest had species of great value such as African teak or iroko and mahogany. The rest is dominated by secondary forest in which other fire-resistant species, such as palm trees, predominate. The savannah prevails towards the north, as the rains decrease, favored by burning and grazing, with small areas of typical savannah, of tall grasses of the tussok type and low, scattered trees, and another type of savanna derived from logging forest, with tall grasses and fire-resistant trees. On the coast there are residual mangroves, especially in the tidal areas of river estuaries, with the presence of Raphia vinifera, a type of palm tree.

The fauna was seriously affected during the civil war of 1991-2002, which allowed all types of animals to be freely hunted, such as elephants, lions, hyenas, leopards or buffaloes, which are not seen outside of protected areas. There are chimpanzees in the forests. Potamoqueros and antelopes are more widely distributed. In the rivers there are crocodiles and dwarf hippos and manatees. On the coast there are tunas, barracudas, herrings, greenfish and crabs.

The mangroves

Mangroves are found in the coastal zone, in tidal areas and at the mouths of rivers. Trees and shrubs raised on roots up to 20 m high are common. Along the streams, the trees are larger and the forest denser, forming gallery forests for all intents and purposes. In the flat swampy areas between the streams, the trees are not as tall and the forest is less dense. The dominant species are Rhizophora racemosa (red mangrove), Rizophora mangle and Rhizophora harrisonii (cobbler mangrove). The red mangrove is a pioneer along the shore. The other two grow at the tidal limit, along with Avicennia germinans (white or black mangrove, depending on the case), Conocarpus erectus (buttonwood or Zaragoza mangrove) and < i>Laguncularia racemosa (patabán or white mangrove). On the periphery of the mangroves, grasses grow alongside ferns and halophytes. The mangroves extend as far as the tides reach upstream. Where the land is more consolidated and fresh water predominates, onlyR grows. racemosa, red mangrove, which reaches 35 m. The largest areas are in the north of the country and the largest centers are in Yawri Bay, the estuaries and islands beyond Freetown and the coastal and estuarine complex beyond Sherbro Island where it joins the Sherbro River.

Protected areas

In Sierra Leone there are 50 protected areas that cover an area of 6,825 km², 9.39% of the territory (72,709 km²), and 863 km² of marine areas, 0.54% of the 160,453 km² that belong to the country. There are 8 national parks, 29 forest reserves, 3 strict nature reserves, 1 game reserve, 3 forest game reserves, 1 game sanctuary and 4 marine protected areas. In addition, there is 1 Ramsar site.

National parks

• Gola Rainforest National Park, 710 km2
• Outamba National Park, 738 km2
• Kilimi National Park, 388 km2
• Loma Mountain National Park, 332 km2
• Kuru hill national park, 70 km2
• Sonfon Lake National Park, 52 km2
• Mape Lake National Park, 75 km2

Strict reservations

• Strict natural reserve of Mamunta-Mayoso, 20.7 km2
• Strict natural reserve of the Sulima mangrove, 26 km2
• Strict natural reserve of the Bonthe mangrove, 998 km2

Ramsar Sites

• Sierra Leone River Estuary, 2950 km2

Forest reserves exempt from hunting

• Sanctuary protected from Tiwai Island, 12 km2
• Sankan Biriwa Forest Reserve (Tingi Coils), 119 km2
• Western Area Forest Reserve, 177 km2
• Sewa-Waanje Reserve, 100 km2
• Kangari hill forest reserve, 85 km2

Marine protected areas

• Scarcies River Estuary, 102.4 km2
• Sierra Leone River Estuary, 249 km2
• Sherbro River Estuary, 283 km2
• Yawri Bay estuary, 196 km2

Ethnic groups of Sierra Leone

In Sierra Leone, the estimated population in 2020 is 7,976,983 inhabitants, with a population density of 111 inhabitants/km². 43.3% are urban, and the average age is 19.4 years, with a life expectancy of 56 years and an infant mortality rate of 70 per thousand (96.3 under 5 years of age). The forecast is that in 2050 they will reach 13 million inhabitants.

There are 18 ethnic groups that have similar cultural characteristics: secret societies (poro and sande), patrilineal descent and agricultural methods. By number of members they are: temne (35.5%, in the center and northwest), mende (33.2%, in the east and south), limba (6.4%), kono (4.4%), fullah (3.4%), loko (2.9%), Koranko (2.8%), Sherbro (2.6%), Mandinka (2.4%) and Creole (1.2%, descendants of Jamaican slaves freed near Freetown a end of the 18th century, also called krio), and other groups (4.7%), in addition to 0.3 % of foreigners including refugees from the Liberian civil war, Europeans, Lebanese, Pakistanis and Indians, plus a small undetermined group of 0.2%.