Question

Which one of the following is the main cause of soil erosion?
A) Agriculture
B) Industries
C) Deforestation
D) Urbanization

Answer 1

Hint: Soil erosion is a form of soil degradation that involves the displacement of the top layer of soil. The dynamic behaviour of erosive agents, such as water, ice (glaciers), snow, air (wind), plants, animals, and humans, causes this natural process. Soil erosion can be a gradual process that goes unnoticed, or it can happen quickly, resulting in a significant loss of topsoil. Reduced crop production capacity, lower surface water quality, and degraded drainage networks can all be consequences of soil loss on farmland.

Complete answer:
By removing the humus and litter layers from the soil surface, removing the vegetative cover that holds soil together, and causing heavy soil compaction from logging machinery, deforestation causes increased erosion rates due to the exposure of mineral soil. Infiltration rates are high and erosion is poor after trees have been removed by fire or logging, as long as the forest floor remains intact. If severe fires are accompanied by heavy rain, they can cause substantial additional erosion.

Now let us look at the given options:
Agriculture: This option is incorrect because although agriculture is one of the reasons for soil erosion yet it is not the main reason. A high percentage of soil erosion is caused due to deforestation.
Industries: This option is incorrect because deforestation is the main cause of soil erosion.
Deforestation: This is the correct option. Deforestation is the main cause. Trees and their roots provide an anchor for the soil as well as protection from the wind and rain. When forests are destroyed, the land is left exposed, vulnerable to being washed or swept away by the weather.
Urbanization: This option is incorrect because although the water holding capacity of the soil decreases as a result of urbanization, and runoff rates rise, resulting in soil erosion yet it is not the main reason for soil erosion.

Thus, the correct answer is Option C.

Note: The removal of a forest or stand of trees from land that is then converted to non-forest use is known as deforestation, clearance, clearcutting, or clearing. Forest land can be converted to fields, ranches, or urban use as part of deforestation. Tropical rainforests have the highest concentration of deforestation.