CBSE Class 9 Answered

Dear student,

The various causes are:

i) Human activities: These include faulty farming systems, deforestation caused by overgrazing, clearance of land for agricultural purposes and construction, dam construction and diversion of the natural course of river, and mining activities are just a few among the various human activities which have either directly or indirectly weakened the topmost layer of the planet, thus making it vulnerable to excessive wearing away by the various agents of erosion. For instance, tree roots help in holding the soil together, and therefore depletion of vegetation cover is bound to make soil vulnerable to erosion by running water.

ii) Natural Causes of Soil Erosion: There are a few natural causes of erosion as well. The major natural factors that can cause soil erosion include:

Gradient of Slope: Gradient of the slope is an important factor when it comes to soil erosion. The steeper the gradient, higher is the rate of erosion and vice versa.

Soil Properties: The vulnerability of a piece of land to soil erosion depends on the physical and chemical properties of the soil as well. Different types of soil have different physical and chemical properties. The texture, structure, water retention capability, etc. play an important role in determining whether the soil is susceptible to erosion by various agents of erosion or not.

Water Flow: Hydrological cycle, especially the surface flow as well as underground flow also play a major role in soil erosion. Variation in the velocity and type of the flow determine the gradient of soil erosion.

Climate: One of the major soil erosion causes, climate determines the precipitation levels and wind velocity, which in turn effect soil erosion. More precipitation means more surface flow, and more surface flow means more area vulnerable to erosion by running water. Similarly, if the wind velocity is high, erosion will also be high and eroded material will be carried farther.

Regards, Team Topperlearning