The Sahel region of central Africa is arguably one of the most impoverished and environmentally damaged geographic regions on Earth. Aptly named Sahel, after the Arabic word for ‘border’ or ‘margin’, it comprises of the 300km wide mass of arid land south of the Sahara Desert and north of the tropical southern zones. (Gritzner 3) It intersects many of the major nations of central Africa including, but not limited to, Senegal, Mauritania, Mali, Burkina Faso, Niger, Nigeria, and Chad.
Spanning from the Atlantic, east to the Indian Ocean, the steppe-like Sahel supports sparse vegetation and infrequent wildlife in comparison to the lush low land rain forests of the south. The chief hydrographic feature is the lengthy Niger River, which cuts through Niger and Mali. The smaller Podor River also follows the northern border of Senegal emptying into the Atlantic Ocean. Since the Sahel is enclosed by desert and rainforest on either side, a dry steppe-plateau region results to the north, with grasslands and meager savanna in the south.
The land is generally dehydrated, dusty, and flat. The climate of the Sahel is barely inviting. The weather patterns of the region are highly irregular and show signs of drastic change over the past centuries. Two major air masses dictate climate control. A dry air mass known as the “Continental tropical mass” blows over the steppe and northern savannah throughout the 8-month dry season from October to May. It is followed by a lightly rainy season concentrated in the southern regions that lasts through September.
This is called the “Maritime tropical mass”. (Gritzner 8) Between these two alterations, a zone known as the “Intertropical Front” circles between the Gulf of Guinea in January towards the 25 degree parallel north in August. (Raynaut 12) Throughout the winter months a great wind called the “Harmattan” blows from the north, darkening the skies of western Africa with the heavy gray dusts of the Sahara. Temperatures generally range between 20 and 30 degrees Celsius but can reach 40 degrees and above in the early summer of March and April.
The dry heat and low humidity is a large deterrent on local attempts at agriculture. The only sources of water are the windy Niger River, the narrow coasts of the east and west, and the extremely limited rainfall. To make matters worse, the average annual rainfall of the region has declined by almost half since the beginning of the 20th century; falling from 409. 6 mm per year in 1901 to 262. 9 mm per year in 1985. (Raynaut 15) Since it is a buffer zone, the Sudan is in constant change between the surrounding environments.
It is almost like the ribbon in the center of a tug-of-war rope. At times the Sahara will creep southward bringing an onslaught of desert-like conditions and temperatures. Other years the lush forests of the south will send the rainy belt north brining much needed precipitation. (Renner 584) This irregularity as well as decreasing overall rainfall resulted in an infamous drought starting in the late 60s and extending through the late 80s, which resulted in well over 100,000 lives lost through famine. Newman ii) Scientists have also recently discovered climatic trends have altered from warm to cool every 50,000 – 60,000 years in African history. (Gritzner 6) Currently in the later Holocene era, it is expected to reverse to cool again in another 30,000 years bringing another drastic change in permanent climate. The soils of the northern Sahel region are brown to gray raw mineral soils. They are very dry, resting on ancient ergs with clay accumulation under the surface. They are virtually void of nutrients and hardly capable of absorbing and holding the limited rainfall of the region.
Surface and vegetation is fragile as a result. (Raynaut 30) However, a benefit is the hard clay foundation soils are extremely resistant to erosion. Further south they turn to saline/desert soils on Aeolian deposits. These sandy, unfastened soils are much more welcoming of water and natural nutrients and make for populated pastureland. However, according to the Carte du Danger de l’erosion en Afrique du Sud du Sahara this area is also at the highest risk for soil loss potential and threat of draught.
Over 2,000 tons per km2 of dirt a year are potentially moved or lost. Newman 41) In contrast, the lands along the Niger River valley contain narrow sandstone gorges and broad fertile alluvial plains popular among local farmers and nomadic herders. Following the patterns of climate movement and soil positioning, vegetation subgroups span from north to south starting with the dry desert-like herbaceous or shrub steppe in area directly below the Sahara. Here there are scattered, shorter grasses and very few tree species. The majority of the Sahel, however, consists of wide and flat savannah.
This stereotypical African landscape contains scattered shrubs and hardy independent trees. The two most popular and reoccurring of these are the broad, flat topped, enchanting Accacia, and the thick, stunted, renowned root-topped Baobob. (Kuchler 76) These trees are scattered intermittently and generally stand alone on the horizon. They are supported by extensive root systems running deep into the underlying clay earth, and they have survived through the centuries due to thick dense trunks and resistance to natural threats.
Although infrequent, these trees provide the few areas of shade in the Sahel to escape the heat of the dry Saharan summers. The savannah region also contains vast grasslands nourished in the brief rainy season. Unfortunately, since the wildlife and livestock of the Sahel are forced to follow the rain, mass overgrazing has led to a desertification epidemic in the already struggling landscape. The young soils along the coastal zones of Senegal and Niger River create a profitable area for livestock rich in vegetation, dense trees and nutrient rich grasses.
However, “thought botanists have emphasized the floristic contrasts between the northern and southern savannas, the Guinea shows a high degree of geographic unity. ” (Gleave 127) It has been said, “People visit East Africa to see the animals and West Africa to see the people. ” While there are limited populations of the “traditional” African wildlife, such as elephants and lions, the majority of the natural occurring animals of the Sahel are much smaller, herbivore, low-maintenance species. These include Barbary sheep, Nubian wild ass, small forest buffalo, and a wide variety of gazelles and antelope.
The bird life of the region is highly diverse and influential. It includes over 300 species of birds deriving from over 51 families. (Gritzner 33) Some examples are birds of prey, doves, seabirds, long-legged river birds, hornbills, and songbirds. In addition, an array of reptiles can be found especially along the Niger River. Crocodiles are scarce but the best known of these reptiles. Snakes such as the adder and spitting cobra are also popular, as well as a seemingly endless collection of lizards ranging from 20cm to 2 meters in length.
Scorpions, fire ants, spiders, millipedes, and of course the malarial mosquito are all insects of the Sahel that pose a threat to the peoples of the area. The rise of an agricultural population in the western Sahel region began over 4,000 years ago as the Saharan nomads trudged their way south across the dry grassy terrain. (Newman 104) The flat plateau nature of the landscape is advantageous to mass movements of people as well as primitive trade routes between clans.