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TOPIC: ENVIRONMENTAL HAZARDS
CONTENT:
- Definition of Soil Erosion – Causes, Effects and Control of Soil Erosion
- Definition of Flooding – Causes, Effects of Flooding on Communities and
Farmlands, Control of Flooding and Drainage Patterns
DEFINITION OF SOIL EROSION
Environmental hazard is a term used for any situation or state of events which poses a threat to the surrounding environment and adversely affect plants and animals
SOIL EROSION is the washing away of the soil by heavy rain or wind resulting to the formation of gullies and landslides and leaving behind silt on which plants can no longer grow.
Soil erosion can also be defined as the removal of topsoil faster than the soil-forming processes can replace it, due to the natural, animal, and human activity (overgrazing, over-cultivation, forest clearing, mechanized farming, etc.). Soil erosion results in land infertility leading to desertification and devastating flooding.
CAUSES OF SOIL EROSION
- Excessive Rainfall: Due to excessive rainfall, the top fertile soil is washed away.
- Human activities: Human activities accelerate the disappearance of a protective cover of natural vegetation and cause soil erosion.
- Overgrazing: Overgrazing leads to the absence of ground vegetation, causes gradual depletion of soil organisms, and soil erosion.
- Land use: Humans play a major role in soil erosion through their use and abuse of natural resources, for example, deforestation, grazing, arable land use, faulty farming systems, high crop intensity, construction, mining, etc.
- Climate: The two most important climatic factors having a direct effect on erosion are precipitation and wind velocity.
- Landforms: Slope, gradient, slope length, and shape of the slope are the important variables of landforms that affect erosion processes for all types of soil erosion, e.g., splash, sheet, rill, and gully erosion.
- Bush burning
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