The Sahel, comprising portions of ten (10) African countries, from left to right: [northern] Senegal, [southern] Mauritania, [central] Mali, [northern] Burkina Faso, [southern] Algeria, [southwestern] Niger, [northern] Nigeria, [central] Chad, [central] Sudan and [northern] Eritrea.

Climate The climate of the Sahel is arid and hot, with strong seasonal variations in rainfall and temperature. The Sahel receives about 200-600 mm (6-20 in) of rainfall a year, which falls mostly in the May to September monsoon season. Rainfall is generally higher in the south, declining rapidly as one reaches the northern edge of the Sahel. The rainfall is characterized by great variation from year to year and from decade to decade, determined by the movements of the Intertropical Convergence Zone (ITCZ). There is a strong correlation between rainfall in the Sahel region and intense hurricane activity in the Atlantic. Monthly mean temperatures vary from a maximum of 33oC to 36oC to a minimum of 18oC to 21oC. During the winter, hot, dry Harmattan winds off the Sahara can bring sand and dust storms (Source: Wikipedia).

Transhumance Traditionally, most of the people in the Sahel have been seminomads, farming and raising livestock in a system of transhumance, which is probably the most sustainable way of utilizing the Sahel. The difference between the dry north, with higher levels of soil nutrients, and the wetter south, is utilized so that the herds graze on high quality feed in the North during the wet season, and trek several hundred kilometers down to the south, to graze on more abundant but less nutritious feed during the dry period. Increased permanent settlement and pastoralism in fertile areas has been the source of conflicts with traditional nomadic herders (Source: Wikipedia).

Sahelian Drought There was a major drought in the Sahel in 1914, caused by annual rains far below average, that caused a large-scale famine. The 1960's saw a large increase in rainfall in the region, making the Northern drier region more accessible. There was a push, supported by governments, for people to move northwards, and as the long drought-period from 1968 through 1974 kicked in, the grazing quickly became unsustainable, and large-scale denudation of the terrain followed. Like the drought in 1914, this led to a large-scale famine, but this time it was somewhat tempered by international visibility and an outpouring of aid (Source: Wikipedia).