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Discuss how human activities can accelerate soil erosion - Leaving Cert Geography - Question 17 - 2009
Question 17
Discuss how human activities can accelerate soil erosion. [80m]
Worked Solution & Example Answer:Discuss how human activities can accelerate soil erosion - Leaving Cert Geography - Question 17 - 2009
Step 1
Identify 3 aspects of human activities that accelerate soil erosion
Answer
Human activities such as deforestation, agriculture, and urban development can significantly accelerate soil erosion.
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Deforestation: The removal of trees and vegetation reduces the soil's stability, making it more susceptible to erosion by wind and water. Without tree roots to anchor the soil, rain can wash away topsoil more easily.
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Agriculture: Intensive farming practices like plowing and monoculture leave the soil bare and vulnerable. When crops are continuously grown in the same area without proper crop rotation or cover crops, the soil loses its structure and nutrients, which increases erosion rates.
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Urban Development: Construction activities disturb the land and remove vegetation, leading to increased runoff. Impervious surfaces such as asphalt and concrete prevent water absorption, exacerbating erosion in nearby areas.
Step 2
Discuss how these activities lead to soil erosion
Answer
These activities lead to soil erosion through several mechanisms:
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Disruption of Soil Structure: Both deforestation and agricultural practices disturb the natural soil structure. The loss of organic matter and soil compaction makes it harder for the soil to retain water and nutrients, increasing its susceptibility to being washed or blown away.
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Increased Runoff: In urban areas, the creation of impervious surfaces leads to higher runoff volumes. This runoff can carry away soil particles, especially in areas with steep gradients. The accelerated water flow increases both water erosion and the transport of sediments.
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Loss of Vegetation: Vegetation is crucial for protecting the soil. When it is removed, the natural barrier against rain impact is lost, and the remaining soil becomes more prone to erosion. Additionally, vegetation helps in water absorption, which further reduces surface runoff.
Step 3
Provide examples for each identified aspect
Answer
Examples illustrating these aspects include:
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Deforestation: The Amazon rainforest is experiencing significant deforestation for agriculture and logging, which has led to increased soil erosion and sedimentation in rivers.
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Agriculture: In areas of the Midwest USA, practices such as monoculture corn farming have led to substantial topsoil loss, impacting soil health and leading to increased runoff and erosion.
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Urban Development: In cities like Los Angeles, urban sprawl has increased the amount of impervious surfaces. Rainfall during storms causes flash flooding and significant erosion in adjacent unprotected areas.