This essay will look at the typical nature of arid regions and will look at the impacts to the environment through management from societies living in these areas.
First of all, arid “refers to areas where the climate is extremely dry. Such climates were defined as being areas with less than 250mm of precipitation per year, but in reality this is too simple.” (Skinner et al 2007 p12) The arid zone is characterized by excessive heat and inadequate, variable precipitation. Thornthwaite in 1931, was the first to define an aridity index using the relationship between precipitation and (potential) evapotranspiration, supported by Waugh (1990). However unlike conditions in temperate regions, the rainfall in arid zones differs between seasons. Rabat in Morocco, receives rain during the winter, while the summer is almost null of rainfall. It also varies from one year to another- The difference between the lowest and highest rainfall recorded in years can be significant, but it is usually within a range of 50 per cent of the mean. The variation in monthly rainfall is even bigger. Rainfall and temperature are the biggest factors for aridity, other factors have some smaller influences too. The moisture in the air has effects on the water balance in the soil. When the moisture content in the soil is higher than in the air, this causes water in the soil to evaporate into the air Humidity is generally low in arid zones. “Because of the scarcity of vegetation that can reduce air movements, arid regions typically are windy.” (Waugh 1990 p152) Winds remove the moist air around the plants and soil and, cause an increase in evapotranspiration. Finally, the vegetation cover in arid zones is mainly baron, vegetative growth in arid zones is growth t...
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Fig 1. Developments that lead to a downward spiral of desertification. From Millennium Ecosystem Assessment (2005): Ecosystems and Human Well-Being. Desertification Synthesis. (Accessed Feb 2014)
Land Degradation in Arid regions Environmental science in the 21st century –and online textbook. available at: http://oceanworld.tamu.edu/resources/environment-book/aridlanddegradation.html (accessed 16/02/2014)
Laity J. Deserts and Desert Environments (2008) Wiley-Blackwell
Skinner M, Redfern D, Farmer G. (2008) Complete A-Z Geography Handbook 3rd edition Hodder & Stoughton
Water and climate change: improving access and management in semiarid Brazil ELLA from Latin America http://ella.practicalaction.org/sites/default/files/111104_ENV_AdaSemReg_BRIEF1.pdf (accessed (17/02/2014)
Waugh, D. Geography an Integrated Approach (1990) Neilson
Briggs, John, Joanne Sharp, Nabila Hamed, Hoda Yacoub. The Geographical Journal. London: Blackwell Publishing, 2003. Print
Time and time again it has been seen that human interaction with his/her environment and it’s ecosystems has shown to be increasingly arrogant and self-serving. These endless accounts are proven by the amount of important biological diversity that is being lost to the surrounding environment due to these threats of human development and population growth. There are two forms of these losses of diversity by human hand: direct and indirect. Direct losses would be the destruction of an area needed for human requirements be it social or economical. Examples of these losses would be housing, agriculture, and others. Indirect losses would be those caused by the destruction of an area also needed for the same requirements but the area’s commodities which are valued, water, food, land in general, is needed elsewhere. These losses are few in number compared with those of direct losses yet they are of the greatest importance. They are important because they involve the removal of resources of an area in which other inhabitants are dependent upon. A great example of this regrettable indirect expansion is the loss of the rich habitat of the area known as Owens Valley.
In short, agriculture reliant purely on levels of sufficient rainfall was destined for failure in the Negev desert region, which is characterized by its low precipitation and high evaporation. Moreover, facing the Negev’s unpredictable and sporadic yearly precipitation patterns with “local [rains that] affect[ed] small areas of several km2”, effective farming required a more proactive approach to subsistence
Blij, H.J. de , Peter O. Muller, Jan Nijman, and Antoinette M.G.A WinklerPrins. The World Today Concepts and Regions in Geography. Fifth Edition ed. United States of America: John Wiley & Sons, Inc., 2011. Print.
The weather in this novel controls their crops and the river flow; which controls their food and water supply. They depend on adequate rainfall to help their crops to grow and for the river to be full. They also depend on the sun to warm things up and make the crops grow. However, if there is too much rain or too much sun it can cause many problems, such as a drought or a flood. These things are significant in this novel, because t...
Water shortage in arid and semi-arid regions and declining its availability to a crisis ...
most evident in arid and semi-arid areas. [2] At least 1 million people are permanently
Dry lands is a previous stage into what can develop the atrocity of desertification. These plains of ground lack moisture. These areas lose it either to evaporation or by transpiration of plants. Generally the land that is considered dry lands is still used by primitive technologies within herding and farming. This weak land is put on even l...
“How Slash and Burn Agriculture Affects Geography." About.com Geography. N.p., n.d. Web. 29 Apr. 2014." About.com Geography. N.p., n.d. Web. 29 Apr. 2014.
Saier, M. H., Jr. (2010). Desertification and migration. Water, Air, & Soil Pollution, 205(1-4), S31+. Retrieved from http://go.galegroup.com/ps/i.do?id=GALE%7CA359852755&v=2.1&u=oran95108&it=r&p=AONE&sw=w&asid=d58e000340b9e00632d610b6b1c2b1e4
Agriculture is the major farming activity. Agriculture's scale means not only that large area is directly affected, but that local and even regional climates can be affected. The draining of water from rivers and watersheds for irrigation leads to drier natural habitats. Those rivers that receive runoff from farmland are often poisoned by excessive nutrients and pesticides.
Nowadays it is common to read articles in newspapers and magazines regarding biodiversity issues. Human beings have been knowingly and unknowingly destroying biodiversity since their existence. Biodiversity is the measure of the variety of species of animals living in an area. Forests are usually areas with high biodiversity while deserts are the opposite. Human beings have always destroyed biodiversity either by deforestation, or by some other means. Biodiversity depletion is a natural phenomenon. But the present levels of biodiversity depletion are many times higher than the natural rate. Recently the levels of loss in biodiversity have started causing global concern. Some of the main causes for loss in biodiversity are alteration of habitats, increasing levels of pollution and human population growth.
De, Blij Harm J., and Peter O. Muller. Geography: Realms, Regions, and Concepts. New York: J. Wiley, 1997. 340. Print.
The problem of water scarcity has increasingly spread throughout the world as of yet, The UN reports that within the next half- century up to 7 billion people in 60 countries which is more than the whole present population will face water scarcity (Sawin “Water Scarcity could Overwhelm the Next Generation”). As well the demand for freshwater has tripled over the past 50 years, and is continuing to rise as a result of population growth and economic development. 70% of this demand derives from agriculture which shows the influence of water on food supply globally as well not just drinking water (Sawin “Water Scarcity could overwhelm the Next Generation”). But increasing water use is not just a matter of the greater number of people needing it to drink and eat; it also comes from pollution and misuse of water supplies, by either dumping or runoff of bacteria or chemicals into water. This also “causes other pollutions as well such as soil and air pollution, accelerating wetland damage and human caused global warming” (Smith and Thomassey 25). According to UN report, recent estimates suggest that climate change will account for about 20 percent of the increase in global water scarcity in coming decades.
Drought is a difficult thing to measure, mainly because of all the different factors that are involved when determining the kind of drought, its intensity, and the length of the drought. Because drought can be defined in many different ways by many people, these are the three most frequently used: Meteorological, Agricultural, and Hydrological drought (What is Drought, n.d.). A Meteorological drought is typically defined by the degree of dryness and the span of the dry period. Agricultural drought focuses on the precipitation shortages, soil water deficits, and reduced ground water or reservoir levels needed for irrigation. The Hydrological drought occurs after periods of continuous lack of precipitation that reduces the water supply, impacting the community (What is Drought, n.d.). When determining whether the drought is short...