Theory:

     The flow of water has undoubtedly played a great part and a beneficent one in the geological processes by which the soil on the earth’s surface has been formed from the rocks of its crust. The same agency, however, under appropriate conditions, can also play a destructive part and wash away the soil which is the foundation of all agriculture, and if allowed to proceed unchecked can have the most disastrous effect on the life of the country. The problem of soil erosion is one of serious import in various countries and especially in many parts of India. The conditions under which it occurs and the measures by which it can be checked are deserving of the closest study.

     Soil erosion occurs in successive steps, the earliest of which may easily pass unnoticed. In the later stages, the cutting up and washing away of the earth is only too painfully apparent in the formation of deep gullies and ravines which make all agriculture impossible. Sudden bursts of excessively heavy rain resulting in a large run of surplus water are the principal factors in causing soil erosion. Contributory causes are the slope of the land, removal of the natural protective coat of vegetation, the existence of ruts along which the water can flow with rapidly gathering momentum, and the absence of any checks of such flow. Incredibly large quantities of precious soil can be washed away if such conditions exist, as is too often the case.
Explanation:
  
One of the most important geological process is the simple flow of water. It is one of the primary reasons for the conversion of rocks (from earth's crust) into soil. Though it serves as a huge advantage, there is an equal disadvantage as well. In some circumstances, it erodes the soil which forms the basic layer of all farming lands. If not checked at appropriate conditions, it can have devastating effects for the whole country. Washing away of the soil is one of the grave problems in India, especially being an agricultural country. The causes and measures to avoid soil erosion have to be examined carefully.
 
soil erosion.jpg
Soil erosion!
  
Soil erosion takes place in a step-by-step process. The first few stages may not be evident; but as it progresses to the later stages, the cutting and washing away of the earth's soil is very clearly seen, and it is worrisome. It is visible in the formation of deep, narrow passes which makes the land unfit for farming. Sudden heavy rain is a huge factor contributing to this problem - heavy rains result in massive outflow of water, which washes away the soil along with it. Other factors which worsen this problem are:
  • slope in the land - makes water rush out faster
  • there is no vegetation (trees) on the land, which can naturally check erosion
  • ruts or grooves made by the passage of vehicles, allows quicker, stronger outflow of water
  • absence of any checks of such outflow of water
Such erosions can wash out unbelievable quantities of soil. It is to be noted that such huge amounts of soil are washed away frequently!
 
Meanings of difficult words:
  
No.
Words
Meanings
1
importimportance
2
gulliesravines formed by the action of water
3
ravinesa deep, narrow pass with steep sides
4
rutsa long deep track made by the repeated passage of the wheels of vehicles
5
momentumthe force gained by a moving object
Reference:
State Council of Educational Research and Training (2019). Term-2 English Standard-9. Water - The Elixir of Life - Sir C.V. Raman (pp. 121-145). Published by the Tamil Nadu Textbook and Educational Services Corporation.