Bobby,+Jenny,+Big+David's+Group

Human-Environment Interaction in Africa

toc

=Desertification of the Sahel =



**__Desertification__**

 According to the United Nations Convention to Combat Desertification, desertification is “land degradation in arid, semiarid, and dry sub-humid areas resulting from various factors, including climatic variations and human activities.” Land degradation in this context refers to the reduction or loss of the biological or economic productivity of drylands. In understanding desertification, it is important to recognize that the word does not refer to the expansion of existing deserts. Instead, it occurs because more than a third of the land on Earth is vulnerable to exploitation and inappropriate land use. Much of this results from factors such as poverty, political instability, deforestation, overgrazing, and bad irrigation practices, as elaborated further below.



Desertification is a complex process that results from the failure to balance human demand with the limited supplies of the ecosystem. Humans constantly need resources such as food, forage, fuel, building materials, and water, along with a place to grow crops and livestock. However, these dryland transition regions often have fragile and delicately balanced ecosystems, where a variety of microclimates coexist. Therefore, excessive human activity may stress the ecosystem beyond its tolerance limit, and cause the degradation of land. For instance, the hooves of livestock pound on the soil, increasing the mechanic breakdown of it and ultimately reducing the percolation rate of the soil. This accumulation of fine material, as opposed to solid substrate, makes the land more susceptible to erosion by wind and water. Other activities such as grazing or the collection of firewood eliminate plants that help bind the soil, and adds on to the high rate of erosion. Finally, the high demands for the limited surface and ground water reserves leads to overuse and results in salination.

Regional climate also contributes to this phenomenon. Climate composed of large daily temperature fluctuations, strong winds, and intense yet intermittent rainfall makes the already-fragile soil more vulnerable to erosion.

With so many factors involved, desertification does not occur in linear, easily trackable patterns. Its effects advance erratically across various patches of the world, in areas both near and far away from natural deserts; the lands quickly degrade to barren soil, rock, or sand due to poor land management. Regrettably, an area undergoing desertification is not brought to public attention until the process is well under way. Oftentimes, little or no direct data are available to study the changes or the specific extent of degradation. Scientists are still unsure of whether the changes that take place because of desertification are permanent, or whether they can be stopped or reversed in any way.


 * __Desertification in the Sahel__ **

1. The Region The Sahel is a long, thin region stretching across northern Africa between about 12 to 18 degrees latitude. It is a semi-arid transition between the Sahara Desert to the north and wetter regions of equatorial Africa to the south, and it extends across the continent from the Atlantic Ocean in the west and the Indian Ocean in the east. Desertification in the Sahel region has been increasing in an alarming rate in the past few decades, and the devastation brought to the area has caught enough global attention to instigate the establishment of the U.N. Convention on Combating Desertification and Drought.



2. Causes

 As specified in the above introduction, desertification occurs as a result of both environmental conditions (climatic factors) and human interactions. The situation is no different in the Sahel region.

First are the physical factors that affect the region. In the past four to five decades, Sahel has been experiencing long periods of drought and weaker seasonal monsoons, adding on to the dryness of the land. Upon examination, the causes of this drought seem to be the changing sea-surface temperature in the Gulf of Guinea (on the equator near the Prime Meridian) and the El Nino of the Pacific. When the gulf is warm, the Intertropical Convergence Zone shifts south away from the Sahel region, reducing the African monsoon that brings moist air to the area. This ocean reduction of precipitation is aggravated by environmental feedback. As the land dries out, there is less vegetation on the land. With this lack of vegetation, evaporation rate decreases, and this increases the amount of sunlight reflected from the surface, further increasing the temperature and weakening the monsoon.



Second is the human impact on the land. There are several aspects to this issue, and the first is demography. For the past years, the population of residents in the area increased by more than 3 percent annually, well beyond the 2 percent growth of food production to support the massive number of people. This rapid increase puts considerable pressure on the land inhabited by these people, because they depend on natural resources to survive. Overgrazing, the expansion of farms, and the cutting down of trees for firewood lead to deforestation desertification, as illustrated previously. The presence of nomads due to colonial history, and the need to migrate from their home nations due to political conflicts also worsens the issue by adding on to the grazing effect and the pounding of soil by their constant movement across the land.

<span style="font-family: Arial,Helvetica,sans-serif;">Poverty and lack of proper education are also a part of the problem. Unaware of the specific consequences of their actions, inhabitants may unknowingly strip their lands of minerals and humus without replacement, and use farming methods that are unhelpful to the soil or atmosphere. As an example, the common slash-and-burn methods used by the farmers to clear land for annual agriculture is a main cause of destruction. A few months after harvest, the farmers cut their stalks and burn them, leaving the fields exposed to strong winds until the next sowing season arrives. As ironic as it is, this harms the farmland by removing the topsoil through wind erosion and suffocating the seeds and plants on the surface layer. Bad irrigation techniques is another issue. Because salt is deposited in the soil as the water evaporates, the soil becomes salinated, making the land unsuitable for farming. Despite the inefficiency of the methods, the farmers of the Sahel cannot afford to use more developed and expensive technology, and thus have to resort to the current techniques.

<span style="font-family: Arial,Helvetica,sans-serif;">3. Impact & Consequences



<span style="font-family: Arial,Helvetica,sans-serif;">Loss of fertility and vegetation cover, compounded by the decline of groundwater, characterize desertification, and lead to the loss of biodiversity and productivity. Farmers who a century ago could farm in a small area of land and still gain much are limited by the low percent of yield, in spite of the larger area of farmland. Lower yields from crops or livestock then cause famine, poverty, and conflict: when situations are severe, this may even lead to deaths. For instance, the Sahelian drought in 1968 was responsible for the deaths of between 100,000 to 250,000 people, the disruption of millions of lives, and the collapse of the agricultural bases of five different nations. This also makes people move away from their homeland, cutting off their connections with their land and cultural traditions. This relocation can again put pressure on other fragile land and induce further desertification, leading to another round of relocation. Because sandstorms carried away from the affected lands travel across the world via winds, even people residing far away from the actual area are subject to respiratory problems and skin disorders. The blowing sand also accounts to decreased visibility in cities and clogging in rivers and water catchments.

<span style="font-family: Arial,Helvetica,sans-serif;">Just as poverty is a cause of desertification, it is also the result of it -- hence the abominable cycle. Poorer and marginalized people are forced to farm fragile land, and trying to make living out of this land will eventually lead to further degradation.

<span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">**__Possible Solutions__**

<span style="font-family: Arial,Helvetica,sans-serif;"> The most effective means by which farmers can solve the issue of desertification is to stabilize their environment by intercropping edible perennial plants in their fields. These perennials will anchor in the soil and prevent severe wind or water erosion. The presence of roots and their interaction with underground bacteria will also increase nutrient levels in the soil, such as the concentration of ammonia and nitrate. The fruits and other products from the trees can be eaten by both the humans and surrounding organisms. Afforestation in the area will also increase the yield of annual crops, creating an advantageous situation for both the environment and the farmers. Thus, this can be a beginning step towards solving the grave issue that people in the Sahel and around the world face. Some other methods of tackling desertification include terracing, which prevents rainfall from washing away topsoil and nutrients, and contour stone bunds, which trap organic materials but let water to trickle through. These stone bunds distribute water evenly over fields when it rains, and the materials trapped can be raked across the fields to contribute to humus and improve the quality of soil.

<span style="font-family: Arial,Helvetica,sans-serif;">

=<span style="font-family: Arial,Helvetica,sans-serif;">Aswan Dam =


 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12px; line-height: 18px;">__What is the Aswan Dam?__ **

<span style="font: 12px/19px Arial,Helvetica,sans-serif; margin: 0px;"> The Aswan Dam, also called Saad el Aali in Arabic, is one of the world’s largest dam that captures the Nile River and forms an artificial reservoir called Laker Nasser. The Egyptian Government built the dam to capture and store the annual flooding in the Nile River for irrigation, drinking water, hydroelectricity, and transportation.

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;">


 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12px; line-height: 18px;">__Problems associated with the Aswan Dam__ **

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;"> There were several problems that ensued from building the Aswan Dam. These problems included the relocation of people and historical monuments, pollution, and water loss.

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;"> 1. Relocation of People and Historical Monuments <span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;"> Because the Aswan Dam was built to form Lake Nasser, it submerged the area it encompassed. Therefore, over ninety-thousand Egyptians and twenty Nubian Monuments, including several UNESCO World Heritage Sites, were relocated elsewhere before its construction. Temples, for example, were transported to the shores of Lake Nasser. The Aswan Dam project was thereby detrimental to inhabitants and monuments located near the Nile River.

<span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12px;">2. Pollution

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;"> Pollution is a grave repercussion of the Aswan Dam Project. Before the dam was built, annual floods from the Nile River deposited silt filled with nutrients on valleys. These silts acted like an excellent fertilizer, "making Egypt's otherwise dry land productive and fertile" (PBS). However, the dam trapped these nutrients, making it difficult for lands to be productive and fertile. As a result, farmers were compelled fertilize their lands with artificial fertilizers. When these fertilizers are applied on top of the soil, toxic substances seep through the soil and pollute drinking waters underneath. When people drink the contaminated water, they will be vulnerable to many critical diseases. The figure below shows the increase in the use of Nitrogen, Phosphate, and Potash fertilizers represented by green, blue and pink respectively.

<span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;">3. Water Loss

<span style="font-family: Arial,Helvetica,sans-serif;"><span style="font-size-adjust: none; font-size: 12px; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: 0px; line-height: 19px; margin: 0px;"> Evaporation is occurring at an alarming rate in Lake Nasser-approximately ten to sixteen billion cubic meter of Lake Nasser is evaporating each year. In other words, about twenty-five percent of “Egyptian income from Nile water” is lost. Moreover, because countries neighboring Egypt rely on Egypt’s water supply, this is also a major concern for many Northeastern Africa’s countries. As a result, if the evaporation continues, people will inevitably have less supply of freshwater. Notice that the two figures below illustrate a significant decrease in the amount of freshwater available for a person a year in cubic kilometers.

<span style="font-family: Arial,Helvetica,sans-serif;">


 * __<span style="font-family: Arial,Helvetica,sans-serif; font-size-adjust: none; font-size: 12px; font-stretch: normal; font-style: normal; font-variant: normal; letter-spacing: 0px; line-height: 19px; margin: 0px;">Possible Solutions __**

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;">The Egyptian government must take serious measures to remedy the Aswan Dam’s critical side-effects mentioned above. First, to prevent any more relocation of national monuments nearby, it must pass laws that restrict the expansion of the dam and emphasize the value of such historical sites. Also, because the dam deprives agricultural lands of natural fertilizers, the government should make spillways in the dam and allow minerals and silts to flow into the valley floors. The passages will revitalize the land with essential, but natural, fertilizers. Finally, the evaporation of Lake Nasser would be reduced by raising people’s awareness on this issue. The government’s advertisement on the water loss and possible water shortage in near future may instigate a movement to reduce the emission of greenhouse gases in the society. Thus, the government plays the most crucial role in solving the issues associated with the Aswan Dam.

=<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px; line-height: 27px;">**Oil Pollution in the Niger River Delta** =


 * <span style="font-family: Arial,Helvetica,sans-serif;">__Oil Spills__ **

<span class="s1" style="font-family: Arial,Helvetica,sans-serif;">Humanity’s oil dependency is forcing (or perhaps encouraging) oil companies to conduct dangerous and costly oil drilling operations around the world. When trying to manage an overseas oil operation, many oil companies will ignore laws or common safety regulations to maximize profits; this leads to increases in incidents of spilt oil, man-made disasters that can devastate a local ecosystem. When crude oil is introduced into the environment, it can cover bodies of water and contaminate plants. Birds and seafaring mammals can be smothered in the oil, negating their ability to regulate temperature. The aforementioned and marine animals may ingest oil that will fatally damage their digestive system. In addition, the slick covering the surface of the water can restrict access to light for photosynthetic plankton near the bottom of the water, which can have large repercussions throughout the local food chain. These accidents can be caused by a multitude of reasons, including industrial incompetence, aging equipment or piping, or terrorist, criminal, or rebel attacks. The smallest spills will take at least several months to be completely cleaned. <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">**__Niger River Delta Oil Spills__**

<span class="s1" style="font-family: Arial,Helvetica,sans-serif;">In the Niger River Delta, located in Nigeria as it exits into the Atlantic Ocean, oil spills are a frequent, unchecked, and unregulated occurrence. International petroleum companies, like Shell or Exxon-Mobile, drill for oil in this location, a source that makes up 40% of all US oil imports. Lax government overwatch has led these companies to keep equally lax safety and maintenance standards: the cost of repairing and protecting the sprawling network of pipes around the delta is simply too high for companies to consider, while the price of oil is simply too high to ignore this source. As a result, many of the pipes, which have a fifteen year lifespan, have been in use for more than twenty-five years. The corrosion that these pipes have suffered has led to numerous oil leakages across the network, of which there are too many to be checked. Not only that, but the unprotected nature of the pipes makes it easy for saboteurs to tap in to stockpile oil to be sold on the black market. This process often leaves the pipes damaged or destroyed. On the whole, spills amounting to the recent Gulf of Mexico disaster have been occurring in the river delta every year for the past fifty years. There are currently 2,000 spills pouring oil into the environment unchecked, some of them years old.

<span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">__** Effects of Oil Spills **__ <span class="s1" style="font-family: Arial,Helvetica,sans-serif;">The damage to the environment caused by these spills is irreversible. The mangrove forests surrounding the swamps of the delta have been decimated. Local peoples, who relied entirely upon the river for their livelihood, find their drinking water deadly, their fish contaminated, and their crops poisoned. The life expectancy in these villages has been reduced to little over 40 years. Exposure to the oil has increased instances of skin diseases. The economic downturn caused by the souring of the region’s only source of livelihood has resulted in a massive number of school dropouts among young children, whose parents are unable to afford the cost of schooling. The effects of the oil pollution have totally devastated the region. <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">__**The Unlikely Set of Solutions**__

<span class="s1" style="font-family: Arial,Helvetica,sans-serif;">At the root of the problem, as it is almost always, is money. The Niger River delta is too valuable a source of oil for oil companies to ignore, but maintaining the vast network of pipes to prevent leaks is too expensive. Therefore, the Nigerian government must use the power of law to shift the balance of what it profitable. By imposing and enforcing heavy fines on oil leaks, the situation would change so that performing maintenance of oil pipes would be the more profitable course of action for oil companies. However, seeing as this situation has continued unabated for fifty years, it is unlikely that the Nigerian government would see now as the opportune moment to make new laws, especially since it has a controlling interest in most of the oil platforms in the region. In order to encourage change, the international community must condemn the operations taking place there, refusing to purchase oil from that area. Unfortunately, this response is also unlikely. In fact, as oil around the world begins to run out, it is only likely that we will pursue even more dangerous sources to fuel our dependency.

Citation
__**Desertification in the Sahel Sources**__

"Desertification." USGS Publications Warehouse. N.p., n.d. Web. 1 May 2011. <http://pubs.usgs.gov/gip/deserts/desertification/>.

"Desertification - a threat to the Sahel." Eden Foundation. N.p., n.d. Web. 1 May 2011. <http://www.eden-foundation.org/project/desertif.html>.

"Desertification in the Sahel." Welcome to OceanWorld - Bringing the Ocean to the Classroom. N.p., n.d. Web. 1 May 2011. <http://oceanworld.tamu.edu/resources/oceanography-book/desertificationinsahel.html>.

"Desertification in the Sahel ." Scribd. N.p., n.d. Web. 1 May 2011. <http://www.scribd.com/doc/18754223/Desertification-in-the-Sahel-an-overview-of-causes-progression-and-effects>.

"Desertification: 2. How are desertification and human well-being linked?." GreenFacts - Facts on Health and the Environment. N.p., n.d. Web. 1 May 2011. <http://www.greenfacts.org/en/desertification/l-2/2-consequences-desertification.htm#0>.

"Desertification." Global Education. N.p., n.d. Web. 1 May 2011. <http://www.globaleducation.edna.edu.au/globaled/go/pid/2006>.

<span style="font: 12px/19px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;">__**Aswan Dam Sources**__ <span style="color: #333233; font: 12px Arial,Helvetica,sans-serif; letter-spacing: 2px; margin: 0px;"> 1."Human Impacts on the Nile River." n. pag. Web. 30 Apr 2011. <[|__http://sitemaker.umich.edu/sec004_gp5/the_aswan_dam_disadvantages__]>.

<span style="color: #333233; font: 12px Arial,Helvetica,sans-serif; letter-spacing: 2px; margin: 0px;"> 2."Environmental Impact of the Aswan High Dam." //The Nile River//. Web. 30 Apr 2011. <[|__http://www.mbarron.net/Nile/envir_nf.html__]>.

<span style="color: #1919a7; font: 12px Arial,Helvetica,sans-serif; letter-spacing: 0px; margin: 0px;"> 3."Aswan High Dam." //PBS// n. pag. Web. 30 Apr 2011. <[|__http://www.pbs.org/wgbh/buildingbig/wonder/structure/aswan_high.html__]>.

<span style="color: #333233; font: 12px Arial,Helvetica,sans-serif; letter-spacing: 2px; margin: 0px;"> 4.//UNESCO//. , Web. 30 Apr 2011. <[|__http://whc.unesco.org/en/list/88__]>.

<span style="font-family: Arial,Helvetica,sans-serif;">**__Niger River Sources__**

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">"50 Years of Oil Pollution in the Niger River Delta in Southern Nigeria Video." // ABCNews.com //. ABC News, 06 July 2010. Web. 01 May 2011. <http://abcnews.go.com/International/video/nigerias-silent-oil-spill-11095598>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">"Deepwater Horizon MC252 Gulf Incident Oil Budget." National Oceanic and Atmospheric Administration, 02 Aug. 2010. Web. 1 May 2011. <http://www.noaanews.noaa.gov/stories2010/PDFs/DeepwaterHorizonOilBudget20100801.pdf>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">Merchant, Brian. "Less Than 1% of Oil-Soaked Birds Survive." // TreeHugger //. 08 June 2010. Web. 01 May 2011. <http://www.treehugger.com/files/2010/06/less-1-percent-oil-soaked-birds-survive.php>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">"Oil-spill Anger Applies Only to What’s Visible." // West African News //. AllWest Africa, 06 June 2010. Web. 01 May 2011. <http://www.allwestafrica.com/060620104870.html>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">"Statistics." // ITOPF //. International Tanker Owners Pollution Federation, 02 Nov. 2008. Web. 01 May 2011. <http://www.itopf.com/information-services/data-and-statistics/statistics/>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">"Tanker Oil Spill off S. Korea Coast." // AJE //. Al Jazeera English, 08 Dec. 2007. Web. 01 May 2011. <http://english.aljazeera.net/news/asia-pacific/2007/12/2008525133041570288.html>. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 12px; font-weight: normal; line-height: 32px; margin: 0px 0px 0px 3em; padding: 0px; text-indent: -3em;">Vidal, John. "Nigeria's Agony Dwarfs the Gulf Oil Spill. The US and Europe Ignore It." // The Observer //. The Guardian, 30 May 2010. Web. 01 May 2011. <http://www.guardian.co.uk/world/2010/may/30/oil-spills-nigeria-niger-delta-shell>.