Theory question 205
Environmental Hazards and Conservation(a) Explain the term soil erosion. (b) Write notes on soil erosion under the following headings: (i) causes (ii) effects (iii) methods of pevenetion
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(a) Soil erosion is the removal of the top layer of soil by agents such as running water, wind and moving ice, often speeded up by human activities.
(b)(i) Causes: heavy rainfall and runoff; steep slopes; strong winds in dry areas; deforestation and bush burning; overgrazing; poor farming methods (ploughing up and down slopes, continuous cropping); mining and construction.
(ii) Effects: loss of fertile topsoil and lower crop yields; gullies destroy farmland, roads and buildings; silting of rivers and dams; flooding; desertification; poverty and migration.
(iii) Prevention: afforestation and stopping bush burning; contour ploughing and terracing; cover crops and mulching; crop rotation and fallowing; controlled grazing; shelter belts against wind; proper drainage and check dams on gullies.
Write a few points under each of the three headings.