Ganvié, floating village on Nokoué Lake, UNESCO World Heritage Site,
Lower Ouémé basin, southern Benin
24 November 2011
The Republic of Benin is a relatively small country of 114,736 km2 (between 6°15’ and 12°25’N and 0°40’ and 3°45’E) running in a long strip of c. 660 km from the Atlantic coast to the border with Niger in the far north. In the south, the narrow coastline along the Gulf of Guinea of some 120 km stretches from west to east from the Togolese border to the frontier with Nigeria. In the north, the country borders the Republic of Niger and in the north-west the Republic of Burkina Faso (formerly Upper Volta).
Population and economy
The population of Benin was estimated by the UN in 2003 at 6.7 million. In 2010, the population was estimated to be over 8.8 million with a population growth of 2.98% per annum, a life expectancy of 59 years and a high fertility rate (5.49 births per woman). The south is the most populated area, with three quarters of the total population and a density over 120 inhabitants per km2. French is the official language and up to 40 African languages are spoken, the most important being Fon, which is spoken in the south and Dendi a vehicular language of the north. English is fairly widely spoken because of the proximity of Nigeria.
In Benin, ancient animist beliefs are held by more than half the population. Commonly referred to as ’Voodoo’, these traditional beliefs are built on the belief that any object can have a spirit. The dancing ‘Zangbeto’ fetish is usually the first taste of animism and Voodoo celebration witnessed by tourists.
Even today, the income of the majority of people (70%) is based on agriculture, fishing, hunting, the collection of medicinal plants and other non-timber forest products, etc. There is a rich and varied subsistence agriculture with maize, cassava, yams, cowpea in the south and millet and sorghum in the north and vegetables which are all grown and commercialised across the country in the dry season. In addition, cotton, pineapple, palm oil, and more recently cashew nut, have also become cash crops for export.
In Benin, climate is influenced by maritime and continental trade winds and seasons are essentially affected by the annual displacement of the Intertropical Convergence Zone (ICZ). In July, when the ICZ is situated at its northern most latitude, rains are brought by the southern winds from the sea. In December, when the ICZ lies south of Benin over the Atlantic Ocean, dry and ‘cold’ winds called ‘Harmatan’ blow from the Saharan desert, occasionally bringing dust up to Cotonou and the coast.
Rainfall varies from 900 to 1,400 mm per year with a east-west and south-north decreasing gradient. Rainfall distribution draws two types of climate with corresponding transition: in the south a tropical humid climate (Sub-equatorial or Guinean) with two rainfall maxima in April - July and September - October, and a Sudanian climate from 8°N northwards one maximum in June - August.
In the south of the country, monthly mean temperatures oscillate between 26 and 28°C, with low daily amplitude of 5 to 10°C. In the north, monthly mean maxima are between 35 and 40°C but, between December and February, nights can be very cold with temperatures down to 5 - 10°C. Mean relative humidity decreases from south to north, from over 80% year-round in Cotonou to 50% in average in Kandi (where it can drop under 10% with the Harmatan in the heart of the dry season).
The section below is mainly adapted from Neuenschwander et al. (2011). West African vegetation represented in Benin comprises the Guinean-Congolese humid dense forests, the open forests with grass cover in the Sudanian region, and transition zone between them. On the level of Benin, these are further sub-divided into ten phytogeographical districts, based on plant sociological studies and depending on climatic or, to a minor extent, on soil and geological factors.
1. Guineo-Congolese zone (South Benin)
From the coast to the commune of Djidja in the Zou (7°30’N) the climate is sub-equatorial, rainfall is bimodal with 900 mm of rains in the west to 1,300 mm in the east, and soil is mostly deep and ferralitic. This zone constitutes the so-called Dahomey Gap, where the contiguous forest cover between the two main blocks in Central (Congo, Gabon, Cameroon west to Nigeria) and West African (Liberia, Sierra Leone, Ivory Coast east to Ghana) is interrupted and reduced to small forested islands. No evergreen forest on firm ground is recorded. Small pockets of semi-deciduous dense humid forests are threatened by exploitation of wood and slash and burn. It also includes the depression of the Lama on vertisol and a unique dense humid deciduous forest near Kétou. Mangroves occur in the coastal district and the coastal region is low, flat, sandy, and marshy.
2. Guineo-Sudanian transition zone (Central Benin)
It extends roughly from Dassa-Zoumè to Bembéréké and is characterised by progressive fusion of the two rainfall peaks, with annual rainfall between 1,100 and 1,200 mm. The soil is tropical ferruginous. There are humid semi-deciduous forests, dry forests, gallery forests along streams and rivers, open forests and wooded savannahs as well as numerous granitic inselbergs.
3. Sudan zone (North Benin)
This zone is situated north of latitude 10°N between Gogou and Malanville. The climate is typically Sudanian with 1,150 mm rainfall in the south to 900 only in the north. Humidity is generally low, except in the Atacora mountains and soil is tropical ferruginous. The vegetation is usually dominated by grasses (open savannahs) with islands of dry clear forest and wooded savannahs. Gallery forests are found at the foot of the mountains or along major rivers. Neuenschwander et al. (2011) describes further in details the vegetation of Benin into ten phytogeographical districts.