Sahel is a transitional zone separating the Sudanian Savannah on the south to the Saharan desert to the north. The area is located in the northern part of Africa stretching from the Red Sea to the Atlantic Ocean covering a distance of 3,360 miles and an area of 1,178,850 square miles. The width of the Sahel varies from one region to the other. The Sahel, being an eco-climatic and biographical zone has a variety of distinct and unique physical and biological features and a set of human-environmental conflicts.
Climate Of The Sahel Region
The Sahel region experiences a tropical semi-arid climate, mainly hot and dry conditions throughout the year. The Sahelian climate is influenced by the dry Harmattan winds as well as wind movements within the inter-tropical convergence zone. Rainfall in the region is very low and irregular with an annual precipitation of 200-600mm mainly during the May-September monsoon season. Most of the rain falls in the south. Temperatures, like rainfall, vary from region to region but are mostly hot throughout the year.
Geography Of The Sahel Region
The Sahel is a geographically diverse region featuring a flat terrain with an average elevation of 656 – 1312 feet. The terrain is dotted with isolated plateaus, mountain ranges, steppes, thorny shrublands, grasslands and the Savannah which is the primary vegetation zone. Due to the hot temperatures and highly permeable sandy soils, the region has almost non-existent surface water. Mountainous areas and lake and river deltas such as the Chad and Niger deltas, within the Sahel have been separated as different eco-regions, leaving only minor wetlands within the Sahel eco-region.
Biodiversity Of The Sahel Region
The Sahel lacks in a wide variety of species mainly due to the climatic conditions leading to increased migration of wildlife. The rate of endemism in animals is also extremely low. Species found within the region include the Dorcas gazelle, the Dama gazelle, hartebeest species, and predators such as the wild dog, cheetah, and lion. Populations of these species are however under pressure from human-wildlife conflicts as well as environmental factors. The sahel region is covered by savannah and grassland with some areas with woodland and shrubland. Grass cover id fairly continous and dominated by annual grass specieslike the Aristida atipoides, schoenefeldia gracilis, and cenchrus biflorus . Acacia species are the common trees. Other trees include the commiphora, Africana, Boscia senegalensis, faidherbia albida, and balaites aegyptiaca
Desertification In The Sahel
The Sahel region is vulnerable to desertification due to global warming. Additionally, unstable climatic patterns makes sustainable agriculture difficult. Soil erosion and overgrazing have also contributed to the expansion of the Sahara desert conditions into the relatively mild Sahel region. Over-population in the marginal areas result in exerting pressure on the prodyuctive areas. Desertification has led to threats of food security to the residents of these areas while endangering the existing animal and plant species. Despite efforts by various international organizations such as UN, the region remains under threat. Dust storms are a common feature in the region and a major desert storm hit Chad in 2004. Similarly, a major sand storm in 2010 hit Guinea, Gambia, Sengal, Guinea-Bisau, and parts of Sierra Leone.