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Desertification Discuss the issues raised by the cartoon. What is its central point? Who might have published it? Sahelian Africa Sahel: A semiarid region of north-central Africa south of the Sahara Desert Background to the Sahel • The countries comprising sub-Saharan Africa depend more on their natural resource base for economic and social needs than any other region in the world. • Two-thirds of sub-Saharan Africa's people live in rural areas and rely on agriculture and other natural resources for income. • Environmental problems of sub-Saharan Africa include air and water pollution, deforestation, loss of soil and soil fertility, and a dramatic decline in biodiversity throughout the region. The Sahel regions are areas which experience desertification. Desertification is when a desert gradually spreads to the surrounding areas of semi-desert. Why?...... What is it ? "...'desertification' means land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities; Why does the Sahel suffer from desertification? DESERTIFICATION Increase in cattle Increase in population Deforestation for fire wood Grassland grazed more intensively Roots no longer hold soil together Roots may be eaten as well as grass Leaves no longer protect soil from weather Less vegetation means less protection from weather Loose top soil blown away by wind Loose top soil blown away by wind (Soil Erosion) (Soil Erosion) = DESERTIFICATION = Since the 1960s the Sahel has been afflicted by prolonged periods of extensive drought. The above plots are June through October averages of the Sahel rainfall series. The averages are standardized such that the mean and standard deviation of the series are 0 and 1, respectively, for the periods identified in each plot. Sahel rainfall is characterized by year to year and decadal time scale variability, with extended wet periods in 1905-09 and 1950-69, and extended dry periods in 1910-14 and 1970-1997. More than half of Africa is now in need of urgent food assistance. The UN's Food and Agriculture Organisation (FAO) is warning that 27 subSaharan countries now need help. BBC News 31st January 2006 How can population growth cause desertification ? High Birth Rates Increase in demand for fuel wood. Increase in population More immigrants from surrounding countries affected by civil war. Increasing pressure on the land. Fuel wood needed for cooking Villagers are forced to walk further to collect wood. More people working will increase desertification Farmers grow crops on the marginal land where the land is most at risk from erosion. Fields are not given a chance to recover. (Soil Erosion) Accelerated Rate of Desertification. (Soil Erosion) = DESERTIFICATION = How much is population growth to blame? • Sub-Saharan Africa has one of the world's fastest growing populations (approximately 2.2% a year), and is expected to be home to over a billion people by 2025. • In recent years, population growth rates have declined from 2.4% in 1997 to an expected rate of less than 2% by 2006. The problems in the Sahel.. • Only a small portion of the total land area of the Sahel is suitable for ecologically and economically sound agriculture. •The ratio of inhabitants to available agricultural land thus presents a much darker picture than the low population density might suggest. • The highest population densities relative to cultivable land are 633 people per sq km in Mauritania, 293 in Mali, and 228 in Burkina Faso. In Senegal the rate is lowest at less than 100 people per sq km Limiting Desertification In Niger in West Africa desertification has led to increased food shortages in an area where food is already scarce. One of the projects combating desertification encourages farmers to plant edible, drought-resistant perennial species that do not need watering or fertilisers. The continued presence of the plants throughout the season prevents erosion of topsoil by wind. Chinese workers dig a well to water plants to protect a highway in the Taklimakan Desert, the world's second largest moving desert. Planting tree belts, building sand fences and covering dunes with grids of straw and spraying dunes with petrol are some of the ways people are combating desertification. According to Chinese research the speed of desertification in the Taklimakan area has decreased by 50% in the past 10 years. The Results of desertification Soil looses its protective cover, contains less humus and holds less moisture. As the soil becomes exposed to the wind it becomes increasingly at risk from erosion. Desertification is avoidable with the following actions: Terracing any slopes to reduce run off and increase soil moisture. Less Intensive use of the land. Let it recover and have fallow time before using the land again. Desertification is avoidable with the following actions: Planting tress that are good for building materials and fruit. Planting hedges around fields to stop wind blowing the soil away. Desertification is avoidable with the following actions: Using branches for fuel not whole trees. Allow the land to fallow. What about the role of governments? • Some three million people are going hungry in Zimbabwe, which used to be the region's bread basket. Most donors say the government's seizure of productive, white-owned farms has worsened the effects of poor rains. • The government has also been accused of only delivering food aid to its own supporters and punishing areas which vote for the opposition. • Conflict obviously makes farming difficult, as people either run away from their fields or are too afraid to venture too far from their homes. • Farmers and pastoralists in countries such as Somalia and Democratic Republic of Congo face constant harassment by armed men. What can be done? • Immediate deliveries of food aid will obviously stop people starving but are not a long-term solution. • Economists say that modernising agriculture is the best way forward, so farmers use more efficient techniques, such as irrigation. • Some say the key would be to give farmers title-deeds to their land, so they could use it as collateral to borrow money to invest. • In many countries, rural land is held on trust by tribal chiefs and handed out to individual families. • But changing systems such as this would take many years to take hold in more remote areas, where people's lives have hardly changed for hundreds of years. Read the worksheet you have been given and then answer these questions: 1. What are the causes of desertification ? 2. What does population have to do with desertification ? 3. How is the population affecting the Sahel ? 1. Getting in a spin over desertification. 1 = Causes of desertification. 2.Effects of Desertification/ Cut out the spiral and Then write down the solutions on the back. 2.