Drought and desertification in the Sahel

Starter

What is drought? Drought is a period below average rainfall. Drought is period of unexpectedly low rainfall. Therefore, what is considered to be a drought may vary widely throughout the world e.g. in an equatorial climate it could mean 6 days without rain/in Libya it could mean less than 180 mm in a year.

Introduction: Drought and desertification in the Sahel The Sahel is a band of semi-arid land to the south of the Sahara desert. This region includes the region of Darfur, in Sudan, that we studied last lesson. The rainfall in the region is variable and falls mainly during July and August. Rainfall levels used to be higher but now drought is occurring. In wetter times, the Sahel became more populated. Trees were cut down for fuel and cattle were introduced and the vegetation became overgrazed and depleted. Now lower levels of rainfall are being experienced and desertification is taking hold.

Causes of Drought Watch the video clip and note down the causes of drought in the Sahel.

Causes: The Sahel is the most drought prone region of the world and has experienced below average levels of rainfall for the last 30. Reasons for this are: The area has experienced long periods of high pressure. Clouds don’t form in these conditions and so it does not rain. Long periods of high temperatures have led to more evaporation than precipitation. Reduced vegetation as a result deforestation/overgrazing means that more water vapour is lost from the system reducing the potential for rain. Global warming could be making drought more frequent in the Sahel.

Effects: People are forced to migrate wetter areas or to refugee camps where there might be water available Land that was fertile becomes eroded and turns into desert (desertification) Livestock is not able to survive in these conditions and many die Crops fail and this leads to hunger and famine

Desertification Desertification is the process by which productive land becomes dry and useless. There is no one reason we can point to as the cause of desertification, but rather a combination of climate and our own mistakes, ignorance and actions.

Causes of desertification Desertification is triggered mainly by the overuse of land and unsustainable agricultural practices (overcropping, overgrazing, poor irrigation and deforestation) which lead to­ a loss of natural vegetation and healthy soil. An expanding human population and urban living area as well as the low level of priority placed on environmental protection efforts also contributes.

Desertification Threat While deserts expand and contract naturally, it's important to understand that desertification is different from this natural cycle. Desertification is also far from being a new global crisis: Ancient empires, including Sumeria, Babylon and Rome, were dealt its debilitating effects. Currently, the most endangered regions are near the world's five main deserts, including the Sonoran Desert, (Mexico and the US), the Atacama Desert (South America); the Kalahari Desert (Southern Africa); most of Australia; and the large desert mass made up by the Sahara, Arabian, Great Indian, Taklimakan, and Gobi deserts. Desertification is a looming crisis in Africa where almost 70 percent of the continent is arid or semi-arid land. More than 30 percent of North America is comprised of arid or semi-arid lands, with about 40 percent of the continental United States at risk for desertification

The 1930s Dust Bowl

Watch the video clips to see the causes and impacts of desertification http://www.youtube.com/watch?v=8mUhtFe2ApE – Impact Senegal http://www.youtube.com/watch?v=DGGctK4aWGg&feature=related – Animation – grazing and desertification http://www.youtube.com/watch?v=icG7O-laum8&feature=autoplay&list=PL94647A699E6BB886&lf=results_video&playnext=1- Desertification in Niger

Task Complete the flow diagram task to explain the causes and affects of desertification.

Sahel: Reducing Drought and Desertification Measures and effectiveness of measures: Much of the aid provided to the region is the form of food donations (emergency aid), which undoubtedly save lives but does nothing to address people's vulnerability to future shocks. Irrigation and reservoirs have been constructed: These have supplied water to some areas although only 4%, of a possible 20%, of land has been irrigated. They have also served as breeding grounds for disease carrying insects e.g. the tse tse fly. Bore holes and wells have been dug to access underground sources of water again, this has provided more water to some regions although increases in wells have led farmers to attempt to raise larger herds on the land leading further over-grazing Governments in this region have introduced policies of afforestation (planting new forests)

Suggestions for water management to ensure food and water security in the future The Sahel has a tropical climate is characterized by a very long dry season and very high temperatures reaching at times 35 - 40° C in some places. Thus, solar energy is great, yet, it is under-exploited. Access to water can be improved by using solar powered pumping stations that pump water to areas of need in order to irrigate crops, water livestock or provide potable water. This requires MEDCs to provide the skills and technological know-how required and to support with grants for equipment.

Q - To what extent have drought and desertification contributed to war in the Darfur region of Sudan?