...Drought and Desertification, with Specific Reference to The Sahel Zone, Africa Drought is a prolonged period of abnormally low rainfall, leading to a shortage of water, this can some times lead to desertification, which is the process by which fertile land becomes desert, this can also be caused by deforestation or inappropriate agriculture as well. The worst affected area of both drought and desertification is Africa, particularly the Sahel Zone. Physical Causes The most important physical cause of drought is the lack of water vapour in the atmosphere because this leads to precipitation such as rain, hail, snow and sleet. Lack of moisture occurs when there are high-pressure air systems, as they cannot hold as much moisture. Change in wind direction is also a factor that can cause drought because warm, dry continental air is blown over an area instead of cool, moist oceanic air. This process can also make dry areas wet. Human Causes Deforestation in order to create buildings or for fuel is a human cause of drought and can cause desertification. When buildings are created in areas that used to be forests, drought can occur because there is less soil to absorb moisture and the soil that is there is less able to hold the water, which causes it to dry out, and desertification to occur. The building of a dam on a large river in order to create HEP electricity and provide water for agricultural land can cause droughts because there is less water available...
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...what extent do you agree that the human causes of desertification in the sahel are more important than the physical causes? Desertification is when formerly productive land becomes a desert due to a combination of natural and human factors. It’s a long term change that results in land degrading or becoming poorer, vegetation dying and soil becoming exposed to erosion by wind and rain. The Sahel is an example of where desertification has happened. The sahel is a semi arid region of north central Africa south of the sahara desert. It passes through countries such as Ethiopia, Sudan, Somalia and Chad. The sahel has been turning in to the desert since the late 1940s, this has been caused by drought, population increase, overcultivation, over grazing and cutting firewood. There is only one physical cause of desertification in the Sahel and that is climate change. There have been frequent and very intense droughts that occurred from 1968 to 1974 and then again from 1979 to 1984. Without water for a long period of time the vegetation will die and the soil will turn to dust thus making it more easily eroded by the wind. The intense and frequent droughts are said to be caused by global warming which leads to higher temperatures and an increased evapotranspiration, therefore you could say that the droughts are caused partially by humans as they burn the fossil fuels causing global warming. The other four causes of desertification; population increase, over cultivation, overgrazing...
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...and thrive in conditions such as these, focusing on the Sahel, Oasis, and Desert environments of the Sahara. Many adaptations have been made from the people living in the environments previously stated and they will be discussed further in the essay. The Sahara being the world's biggest desert, the Sahel slowly succumbing to desertification and deforestation, these are all challenges that people have overcome and adapted to. One of the environments this essay will be consulting is the Desert environment. The Sahara stated before, is the largest in the world, this means that life here will be very difficult due to the lack of water, shade, and grazing land. The Sahara is quickly getting larger and larger and people like the Tuareg nomads have adapted to this environment in many ways. They have adapted to the raging sandstorms by wearing masks or hooded clothing to protect their faces. They move from one place to another and do not remain still for a extended amount of time. Another way they have adapted to the Sahara is by trading goods....
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...chdhcndiucndSahel, Arabic Sāḥil, Sahel [Credit: NSSL/NOAA]semiarid region of western and north-central Africa extending from Senegal eastward to The Sudan. It forms a transitional zone between the arid Sahara (desert) to the north and the belt of humid savannas to the south. The Sahel stretches from the Atlantic Ocean eastward through northern Senegal, southern Mauritania, the great bend of the Niger River in Mali, Burkina Faso (formerly Upper Volta), southern Niger, northeastern Nigeria, south-central Chad, and into The Sudan. The semiarid steppes of the Sahel have natural pasture, with low-growing grass and tall, herbaceous perennials. Other forage for the region’s livestock (camel, pack ox, and grazing cattle and sheep) includes thorny shrubs and acacia and baobab trees. The thorny scrub once formed a woodland, but the country is now more open and relatively traversable by motor vehicle. The terrain is chiefly of the savanna type, with little continuous cover and a dangerous tendency to merge into desert because of overstocking and overfarming. At least eight months of the year are dry, and rain, confined to a short season, averages 4–8 inches (100–200 mm), mostly in June, July, and August. There are also wide areas of pasturage watered by the flooding Niger and Sénégal rivers. Modest crops of millet and peanuts (groundnuts) can be raised in many areas. In the second half of the 20th century, the Sahel was increasingly afflicted by soil erosion and desertification resulting from growing...
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...The Sahel is the name given to the semi-desert region in Africa to the south of the Sahara Desert. The Sahel stretches right across the African continent, and includes parts of Mauritania, Mali, Niger, Chand and Sudan. Life there due to the conditions is a constant battle to survive. Sustainability is the development of the quality of life that do not do any lasting damage to the environment. I would agree in saying that they Sahel is a constant battle to survive. The increase in population, which is currently at about 260 million and is going to double every 20 years, would mean that there will be a greater demand in food production. This would put pressure on the land to be more productive and this would lead to over-cultivation and over-irrigation. The climate has also made conditions worse and a constant battle to survive. There has been a decrease in rainfall of about 29-49% which would mean that they land is badly managed due to the lack of water. The average temperature of the region has increased meaning that desertification has increased by the increase of evapotranspiration which reduces ground and surface water supplies. Factors such as political instability would also mean that the government would probably spend more money going to war and buying arms rather than looking after its people. On the other hand I do not feel that the “use of this region can never be sustainable. There are strategies in which they help the people come together as a community...
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...agriculture (70% of all employment), which is highly sensitive to climate change. Only 4% African farmland is irrigated, making agriculture susceptible to drought. These people have a reduced capacity to cope, e.g. subsistence farmers, who only grow enough to meet the needs of their family and have no income, will be at risk of starvation it climate change affects their crops. Future prediction Areas that are already dry (arid and semi-arid environments) are getting drier. Wetter areas (tropical and sub-tropical environments) are getting wetter. The whole continent is getting warmer – around 0.5 *C warmer in the last century. Impacts of global warming Global warming is causing desertification- the process by which fertile land becomes unusable for agriculture. It’s a major problem in the Sahel region (the belt between the Sahara desert and the fertile area to the south). This causes a decreases in agricultural production, which leads to more poverty, unemployment, malnourishment and starvation. Global...
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...Using named examples assess the severity of global and local threats to biodiversity Biodiversity refers to the variety of species within an ecosystem and is something which is under increasing threats on both a local and global scale. An example of a global threat to biodiversity is desertification. Desertification is the process by which fertile, arable, land loses nutrients and life becoming barren. The Sahel region is an area which has been massively affected by desertification, especially since the 1950’s when farmers and other locals began to move into the areas which were habitable and used them as farmland. The farmers allowed their cattle to graze freely which resulted in overgrazing and thus having a severe impact on the biodiversity of the land as many plant species were grazed out of an area by the livestock. This loss of plant life due to over grazing has not only resulted in the immediate short term damage to biodiversity but also long term damage as the top soil loses all anchorage from the plant roots causing it to blow away or be washed away leaving bare rock which plants can’t grow on naturally in the future. Due to both the short and long term effects of desertification I believe it is one of the most severe threats to biodiversity on a global scale. Another global threat to biodiversity is climate change. Climate change is the changing of global temperatures over a long term scale, primarily caused by the greenhouse effect and the enhanced greenhouse...
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...Adapting to drought in the Sahel: lessons for climate change Michael Mortimore∗ The Sahel’s experience of adapting to changes in rainfall on a scale at least comparable to that of climate change scenarios, between the 1960s and the 1990s, suggests that lessons can be learnt that may have a wider utility for policy in the future. The Sahel is a major global agroecological region and its success in adaptation will influence the achievement of the global Millennium Development Goals. From simple typologies of adaptation strategies, our understanding of adaptive capacity has evolved over time (with accumulating observations) into a contextual model which places drought management at the center of a development process. Climate change impacts in future are very uncertain. Policies and interventions should therefore aim to build on the platform of past achievements and existing local knowledge to enable flexibility and diversity and the protection of assets of small-scale farmers and herders . 2010 John Wiley & Sons, Ltd. WIREs Clim Change 2010 1 134–143 ‘Africa is the most vulnerable region to climate change, due to the extreme poverty of many Africans, frequent natural disasters such as droughts and floods, and agricultural systems heavily dependent on rainfall’.1 ‘the continent’s low adaptive capacity serves as a major constraint to her ability to adapt’ (Ref 2. p. 6). ‘It is uncertain how rainfall in the Sahel, the Guinean coast and the southern Sahara will evolve in this century’...
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...Some parts of the Horn of Africa have been hit by the worst drought in 60 years, the UN says. Large areas of Somalia, Ethiopia, Djibouti and Kenya are in a crisis or an emergency. The Sahel region of Africa has been suffering from drought since the early 1980s. The land is marginal in Sahel regions over cultivation, overgrazing are human activities can lead to desertification especially when it is combined with drought. Drought is a prolonged period of abnormally low rainfall for a specific area, which leads to a shortage of water. A drought occurs when there in to enough rainfall to support people or crops. Sahel is in the Eco-climatic and bio-geographic zone stretch/transition between the Sahara desert (north) and the Sudanian Savannas (south). It is also located between the Atlantic Ocean and the Red sea. Covers parts of Senegal, southern Mauritania, Mali, Burkina Faso, southern Algeria, northern Nigeria, Chad, Sudan, northern Ethiopia and Eritrea Annual rainfall is 200 mm in the north and 600 mm in the south on average. There are not enough wells to access water in the ground to provide irrigation when the rains fail. Since 1985, 77% of tree cover has been cut down, this reduces transpiration from plants and so means rain is less likely. Ethiopia is a very poor country, the 5th poorest in the world. The result of drought is soil erosion, famine, starvation. 60% export food .80% of the population rely on agriculture mainly in subsistence and rain-fed farming and livestock...
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...Discuss the assertion that disasters in Africa occur when hazards and vulnerability meet. Disasters are adverse or unfortunate events especially sudden and extraordinary misfortunes or calamities. Inhabitants of sub-Saharan Africa are threatened by natural disasters. This has led to consequences like poverty and disease (World Risk Report 2013). The assertion that disasters in Africa occur when hazards and vulnerability meet is true. Disasters in Africa tend to affect the vulnerable. Natural disasters occurring in African countries undermine the economic survival of poor communities. Many populations in countries throughout the continent have suffered under the impact of such hazards, which have killed thousands and caused injuries to many others. Mainly it is the vulnerable groups of people and their locations that are exposed to risk of these disasters. It is of paramount importance to note that these disasters can be natural or man-made. It is the scope of this paper to deliberate if disasters in Africa really occur when hazards and vulnerability meet or not. Increasing disaster threats not only reflect the onset of events such as earthquakes or floods, but also the changing demographic and socioeconomic characteristics of the population. A large, violent tornado, for instance, passing through an open field presents little danger. On the other hand, a relatively weak tornado can pose significant risks to human life and can result in great economic losses in densely populated...
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...AGRICULTURAL ADAPTATION STRATEGIES TO CLIMATE CHANGE IMPACTS IN AFRICA: A REVIEW Akinnagbe O.M* and Irohibe I. J. Department of Agricultural Extension, Faculty of Agriculture, University of Nigeria, Nsukka *E-mails: wolexakins@yahoo.com; oluwole.akinnagbe@unn.edu.ng Tel: +2348035399151 AGRICULTURAL ADAPTATION STRATEGIES TO CLIMATE CHANGE IMPACTS IN AFRICA: A REVIEW Abstract Climate change is expected to intensify existing problems and create new combinations of risks, particularly in Africa. The situation is made worst due to factors such as widespread poverty, overdependence on rainfed agriculture, inequitable land distribution, limited access to capital and technology, inadequate public infrastructure such as roads, long term weather forecasts and inadequate research and extension. By lessening the severity of key damages to the agricultural sector, adaptation is the key defensive measure. Adaptation to climate change involves changes in agricultural management practices in response to changes in climate conditions. This paper reviews agricultural adaptation strategies employed by farmers in various countries in Africa in cushioning the effects of climate change. The common agricultural adaptation strategies used by farmers were the use of drought resistant varieties of crops, crop diversification, change in cropping pattern and calendar of planting, conserving soil moisture through...
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...Geography Nigeria is located on the Gulf of Guinea in West Africa and is roughly twice the size of California. Its neighboring nations are Benin, Niger, Cameroon, and Chad. Nigeria is found in the tropics and has two different seasons, the Dry season and Rainy season. The major rivers passing through Nigeria are the Niger, the third largest river in Africa and the Benue, which flows into the Niger River. The Niger Delta sometimes called the Oil Rivers, due to the past production of palm oil. South Africa is the southern tip of Africa, which includes two islands of the southeast tip of Cape Town, Prince Edward and Marion. South Africa is roughly twice the size of Texas. It borders Mozambique, Zimbabwe, Botswana and Namibia. There are two major rivers in South Africa, the Limpopo, a stretch of which is shared with Zimbabwe, and the Orange which flows into the Vaal. The Orange River flows from east to west across the central landscape, emptying into the Atlantic Ocean at the Namibian border (Safrica.info). South Africa is different from Nigeria in that it actually has another country within its borders, Lesotho. It is in the Drakensberg Mountains where South Africa obtains water from the snowcapped peaks of the landlocked nation. Also, South Africa has three capitals, while Nigeria has one, Abuja. Bloemfontein is the capital of the judiciary, Cape Town is the legislative capital, and Pretoria is the administrative capital, as well as the formal capital of the...
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...Biomes Tropical rainforest: * What: Hot and wet areas with broadleaved evergreen forest * Where: Within 5°N and S of the equator * Climate, limiting factors: High rainfall(2000-5000 mm yr-1), high temperatures( 26-28°) and high insolation, P>E rain washes nutrients out of the soil, so nutrients may limit plant growth * Structure: amazingly high levels of biodiversity: plants compete for light thus growing tall to absorb it, so there is a multi-storey profile to the forests called stratification. Many niches and habitat for animals and large mammals can get enough food * Net productivity: produce 40% of NPP of terrestrial ecosystems. Fast rates of decomposition, respiration and photosynthesis. Biomass gain very high, rapid recycling of nutrients * Human activity: more than 50% of world’s human population live in the tropics/subtropics forests exploited e.g. nutrients quickly exhausted by agriculture, commercial logging of timber * Issues: logging, conversion to grazing and to plantations forests exploited for economic development * Examples: Amazon rainforest, Borneo rainforest Desert: * What: dry areas usually hot in the day and cold at night as skies are clear and there is little vegetation to insulate the ground. Tropical, temperate, cold deserts * Where: cover 20-30% of the Earth’s land surface, about 30°N and S of the equator where dry air descends. Most are in the middle of continents * Climate, limiting factors: water...
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...Version 2 General Certificate of Education (A-level) June 2011 Geography GEOG1 (Specification 2030) Unit 1: Physical and Human Geography Post-Standardisation Mark Scheme Mark schemes are prepared by the Principal Examiner and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all examiners participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the candidates’ responses to questions and that every examiner understands and applies it in the same correct way. As preparation for standardisation each examiner analyses a number of candidates’ scripts: alternative answers not already covered by the mark scheme are discussed and legislated for. If, after the standardisation process, examiners encounter unusual answers which have not been raised they are required to refer these to the Principal Examiner. It must be stressed that a mark scheme is a working document, in many cases further developed and expanded on the basis of candidates’ reactions to a particular paper. Assumptions about future mark schemes on the basis of one year’s document should be avoided; whilst the guiding principles of assessment remain constant, details will change, depending on the content of a particular examination paper. Further copies of this Mark Scheme are available from:...
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...Agroforestry in the drylands of eastern Africa: a call to action Bashir Jama and Abdi Zeila Agroforestry in the drylands of eastern Africa: a call to action Bashir Jama and Abdi Zeila World Agroforestry Centre LIMITED CIRCULATION Titles in the Working Paper Series aim to disseminate information on agroforestry research and practices and stimulate feedback from the scientific community. Other series from the World Agroforestry Centre are: Agroforestry Perspectives, Technical Manuals, and Occasional Papers. Correct Citation: Jama B and Zeila A. 2005. Agroforestry in the drylands of eastern Africa: a call to action. ICRAF Working Paper – no. 1. Nairobi: World Agroforestry Centre. Published by the World Agroforestry Centre (ICRAF) Eastern and Central Africa Regional Programme United Nations Avenue PO Box 30677 – 00100, Nairobi, Kenya Tel: +254 20 7224 000, via USA +1 650 833 6645 Fax: +254 20 7224 001, via USA +1 650 833 6646 Email: b.jama@cgiar.org Internet: www.worldagroforestry.org © World Agroforestry Centre 2005 ICRAF Working Paper no. 1 Photos: World Agroforestry Centre Staff Articles appearing in this publication may be quoted or reproduced without charge, provided the source is acknowledged. No use of this publication may be made for resale or other commercial purposes. All images remain the sole property of their source and may not be used for any purpose without written permission of the source. The views expressed in this publication are those of the author(s) and...
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