what is soil erosion anf ehar are its type ?
Answers
Soil is a store house for organic and inorganic plant nutrients and water.
Some soils are rich in organic and humus contents and are more productive while others are less productive and have very poor percentage of organic contents.
The soil is subjected to a continuous and simultaneous depletion or loss and addition of soil resources.
The various soil components are being removed by living organisms and are returning to the soil by way of death and decay of organisms on it. If the rate of removal or loss of components is greater than the rate of addition, the soil will naturally become less fertile.
The various factors which make the soils less fertile are:
(1) Leaching,
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(2) Biological agencies, and
(3) Soil erosion.
Leaching is an important factor which makes the soil poor in its resources. In this process, minerals and organic substances are removed from the top layer of soil by rain water. Biological agencies are also active in causing loss of resources from the soil. Cultivation of crops regularly year after year makes the soil less productive.
In cultivation there are little chances for the compensation of lost nutrients of the soil by way of death and decay of the vegetation which grows on it. Leguminous plants, however, compensate the loss of nitrogenous compounds because bacteria inhabiting in their root nodules fix considerable amount of free atmospheric nitrogen into its compounds, such as nitrites, nitrates, ammonia and so on.
Soil Erosion:
The word ‘erosion’ literally means to wearing away. In soil erosion, fertile soil surfaces are detached and removed from their original places and are deposited at some other places. According to Fox (1950), “the term soil erosion covers a wide range of physical and chemical actions, such as removal of soluble matters, chemical changes, disintegration by frost or by rapid changes of temperature, attrition by dust charged wind, scouring by silt laden currents, alternate impact and succession by storm waves, landslides and so on”. Thus, soil erosion is the removal of soil from its upper part.
There are two main types of erosions, namely:
(1) Normal erosion and
(2) Accelerated erosion.
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1. Normal Erosion:
When the top soils are gradually removed under normal conditions of physical, biotic and hydrological equilibrium it is called normal erosion. Sometimes, it is also called geologic erosion. It is very slow process in which complete equilibrium is maintained between soil removing and soil forming processes. The normal erosion tends to produce wavy or undulating land surface with alternating ridges and depressions. This is accomplished chiefly by means of slow migration of soil particles from soil surface in successive rains. In arid region, wind during the long dry season is an important factor for normal erosion.
2. Accelerated Soil Erosion:
When the removal of soil does not keep harmony with the soil formation and it is much faster than the latter, it is called accelerated soil erosion
A. Climatic Agencies Causing Erosion of Soil:
These are water and wind.
1. Water:
Water is an important factor in soil erosion. Snow and melting ice also remove the top soil to considerable extents. Soil is directly affected by heavy rainfall, rapidly running water and by wave action.
Erosion caused by water may be of the following types:
(i) Sheet erosion:
Uniform removal of a thin layer of soil from large area is called sheet erosion. It is affected by run-off effect of rain water.
(ii) Rill erosion:
In this type of soil erosion, heavy rainfall and rapidly running water produce finger-shaped grooves or rills over the entire field.
etc..
Answer:
naturally occurring compound of metal which are found in the Earth crust is called soil erosion