The correct answer is: a) Jhum Cultivation (shifting cultivation).
Jhum cultivation is a traditional form of agriculture practiced in many parts of the world, including Assam. It involves clearing a piece of forest land, burning it, and then planting crops on the ash-enriched soil. After a few years, the land is abandoned and a new plot is cleared. This practice can lead to significant soil erosion, as the exposed soil is easily washed away by rain or blown away by wind.
Overgrazing is another major cause of soil erosion. When too many animals graze on a piece of land, they can trample the soil and compact it, making it more difficult for water and nutrients to penetrate. This can lead to the loss of topsoil and the degradation of the land.
Industrial pollution can also contribute to soil erosion. When factories and other industrial facilities release pollutants into the air or water, these pollutants can settle on the land and make it more susceptible to erosion.
Ocean currents are not a major cause of soil erosion in Assam. Ocean currents are large-scale movements of water in the ocean that are driven by the Earth’s rotation and the wind. These currents can transport sediment from one part of the ocean to another, but they do not have a significant impact on soil erosion on land.
In conclusion, the correct answer to the question “Which factor contributes significantly to soil erosion in Assam?” is a) Jhum Cultivation (shifting cultivation).