The paper " Causes and Effects of Soil Erosion" is a perfect example of a term paper on agriculture. The term soil erosion means the destruction of soil by the action of wind and water. Some authors have modified this definition to include damage that is caused as a result of human actions (Zacharp, 2011, p. 22). Soil erosion causes much damage. Apart from the environmental damage involved, the financial losses associated with soil erosion are immense. For instance, America loses between $30 billion and $44 billion to soil erosion annually (Pimental et al, 1993), whereas the United Kingdom also loses about £ 90 million (Environment Agency, 1989).
The purpose of this study is to examine the causes of soil erosion, its effects on the environment, and the solutions available to control it, for the purpose of academic study. The Causes of Soil Erosion Soil erosion is mostly caused by climatic factors. They include rainfall and wind as the major factors. Other factors that contribute to soil erosion are mostly caused by human activities. Such activities include mining, urbanization, and vegetative clearing. The topography of the land also contributes to soil erosion.
Rainfall intensity contributes greatly to soil erosion. It is, usually, the main agent of erosion. The amount of intensity influences the magnitude of the erosion. It is the most critical factor. As argued by Blanco (2008 p. 29), the greater the intensity of the rainstorm, the greater the runoff and consequently, soil erosion. The vegetative clearing is another factor that contributes to soil erosion. It is estimated that about 1 million hectares were cleared from the year 2000 to 2010 (SOE 2011 Report). Vegetation has a great role in preventing soil erosion.
It reduces the destructive energy of rain by increasing the soil roughness. This is effective in slowing the runoff velocity. The vegetation also filters the soil particles in the runoff thus preventing further erosion. With less vegetation, the detachment of soil particles increases thus making the soil prone to erosion. Although vegetation is crucial in providing cover and averting erosion, not all vegetation plays this role effectively. A dense and short growing form of vegetation, for instance, grass, is preferable to sparse and tall vegetation.
Dense canopies also limit splash erosion, therefore, reducing soil erosion (Blanco, 2008). Population pressure greatly contributes to soil erosion. In China, for example, an exponential rise in erosion with a rise in the total population was recorded since 220 BC (Wen, 1993). When the population is large, the land becomes scarce, forcing people to farm on marginal land. The farming practices carried out on these lands are, usually, unwise and therefore lead to soil erosion (R. P. C. Morgan). For example, people often farm in mountainous regions such as The Himalayas in China thus exposing the soils to soil erosion.
Rural to urban migration also contributes to soil erosion. People move to urban areas in search of jobs thus leaving arable land untended. This leads to soil erosion as well. The methods used in the management of land also contribute to soil erosion. In Australia, for example, 46% of the land is used for grazing, and a further 9% is used as a modified pasture. An obvious consequence of grazing is the fact that it leads to the loss of vegetative cover which in turn leads to soil erosion.
Mining is another way of utilizing land. About 3 million hectares of land in Australia is used for mining (SOE 2011Report). The Western Australia Goldfields (Gold and Nickel), The Pilbara (Iron ore), Hunter Valley (Coal), and Bowen Basin (Coal and gas) are examples of where mining takes place. These are huge tracts of land compared to other countries. Excavating land in the process of mining leaves soil particles loose and exposed to destructive elements of the weather such as wind and rain thus making the land prone to soil erosion.
Blanco, H. & Lal, R. 2008. Principles of Soil Conservation and Management. Springer
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Food and Agriculture Organization Of The United Nations. 2008. Soil erosion by water: some measures for its control on cultivated lands. Rome, Food, and Agriculture Organization of the United Nations.
Hatton, D. 2011. State of Environment State and Trends of Land Management.
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Pimental, et al. 2005. Environmental and economic costs of soil erosion and conservation benefits.
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Zachar, D. 2011. Soil Erosion, Developments in Soil Science vol. 10. Elsevier