Types of Erosion
It broadly classified in to two:
A. Geologic erosion:
B. Accelerated Erosion:
1. Wind Erosion
2. Water Erosion.
- Raindrop/ splash erosion.
- Sheet erosion.
- Rill erosion.
- Gully erosion.
- Stream erosion.
C. Other types of Soil erosion:
A. Geologic erosion:
It refers to the formation of and loss of soil simultaneously which maintain the balance between formation and various losses.
It is normal process which represents the erosion of soil in its normal conduction without influence of human being. It is also known as natural or normal erosion. The various topographical features such as existing of stream channels, valleys, etc. are the results of geologic erosion.
B. Accelerated erosion:
It is an excess of geologic erosion. It is activated by naturals and man’s activities due is changes in natural cover and soil conditions.
Accelerated erosion takes place by the action of water, wind, gravity and glaciers. Various forces involved in this are:
Attacking force of water or wind which remove and transport the soil particle from one place to another.
Retarding forces which resists the erosion. In general accelerated erosion is known as soil erosion or erosion.
It is sub classified as:
1. Water erosion:
Rain drop erosion
2. Wind erosion:
It is the process of detachment transportation and deposition of soil particles by the action of wind. Basic cause of wind erosion is:
Soil is loose, finely divided and dry
Soil surface is smooth and bare.
Wind is strong to detach the soil particles from soil surface.
It is also known as splash erosion. It results from soil splash caused by the impact of falling raindrops. Factor influencing the rate of erosion are:
Climate, Rainfall, temperature.
Soil its resistance to dispersion and its infiltration rate.
Topography – steepness and length of slope.
Plant cover—living or dead vegetation.
Falling raindrops breaks soil aggregate and detach soil particles from soil mass. Fine soil particles are taken into suspension and the splash thus become muddy. The major effect of surface flow of water is to carry off the soil loosened by splash erosion.
Sheet erosion may be defined as:
Removal of the fairly uniform layer of soil from the land surface by the action of rainfall and runoff
More or less uniform removal of soil in the form of thin layer or in sheet form by flowing water from a given width of sloping land
Sheet erosion, Two basic erosion processes are involved.
Soil particles are detached from the soil surface by falling rain drop.
The detached soil particles are transported away by runoff from their original place.
The eroding and transporting power of sheet flow are dependant upon the depth and velocity of sheet flow for a given size, shape and density of soil particle.
It is sometime known as micro channel erosion. It is the removal of soil by running water with the formation of a areas of small branching channels. There is no sharp time of demarcation where sheets erosion ends and more readily visible than sheet erosion. It is regarded as a transition stage between sheet erosion and gully. Rill of small depth can be ordinary form tillage.
It is removal of soil by excessive concentration of running water, resulting in the formation of channels ranging in the formation of channels ranging in size from 30cm to 10m or gully is to a large ton be filled by normal tillage practice.
Stream Bank erosion:
Stream channel [bank] erosion is the sourcing of material from the side and bottom of a stream or water channel and the cutting of bank by running water. It is mainly due to removal of vegetation, over grazing or cultivation on the area near to the streams banks.
Other forms of erosion:
1. Glacial erosion [due to mass of ice moving very slowly].
2. Snow erosion [due to slow and creeping movement of snow towards slope.]
3. Anthropogenic erosion [ due to activities of human being]