Soil Erosion

Soil is the upper weathered layer of the earth's crust.The vertical section through the upper crust of the earth is called soil profile. Study of soils is called pedology and the process of soil formation is called pedogenesis.1 cm soil formation takes about 200-400 years.

   The removal of the fertile top layer of the earth or any slight disturbance in its structure is called soil erosion. 

.    Photograph: Landslides at Kailashahar to     Dharmanagar road , 23 rd June,2024

 Types of soil erosion:- It is of two types:

(A) Normal or Geological erosion: It is a very slow process  due to normal physical and biological equilibrium without any interference of human beings .

(B) Accelerated Erosion: It occurs rapidly due to physical and biological activities.Rainfall, landslide, earthquake,overgrazing and human activities are the main factors in such case.

Agents of soil erosion: Water and wind are the main two agents of soil erosion.

(A) Water as an agent: Soil particle breaks into finer particles due to the impact of the rain drops of there is an absence of  the vegetation cover.Run off or run away water carries many soil particles, this process is termed as the   splash  erosion. It is rapid on steep slopes and slow in plains. Sometimes excess amount of water percolation results into land slide. The erosion of river banks due to running water is called riparian erosion.

  Water falls, glacier slipping and sea/ ocean waves are the other factors of soil erosion.

(B) Wind as an agent: Dry and unconsolidated soil particles are eroded by winds.(i) 0.05 mm soil particles are transported in suspension; (ii) 0.05-2.0 mm are transported by saltation; and larger sized particles are transported by creeping over the ground. Soil erosion due to wind is common in desert regions.

Effects of soli erosion:

(i) Loss of fertility.

(ii) Gradual reduction of forest cover on hills.

(iii) Destruction and deterioration of cropland.

(iv) It reduces hydroelectric power generation.

(v) Spreading of deserts.

Principles of soil conservation:

(i) Soil must be protected from rainfall impact.

(ii) More water should be percolated.

(iii) Soil particles size should be increased.

 (iv)Formation and widening of gullies must be prevented.

 (v) Velocity of running water should be reduced.

(vi) The  top soil surface must be covered by vegatation.