What are different types of erosion and how do they work?

1 Answer
Apr 5, 2017

Soil erosion occurs due to ice, wind, water, or gravitational forces


Water erosion:
a. Raindrop splash erosion: Raindrops fall with a speed of over 9 m per second. When raindrops hit bare soil with this speed, they beat it into flowing mud. The splashes reach more than 60 cm high and 150 cm away. However if soil is covered with plants, raindrops do not hit the ground with the same speed.

b. Surface flow erosion: Soil particles are moved by runoff. If an area is flat, you cannot clearly see this movement. If there is an inclined area of concern you can see effects of erosion and deposition.

c. Channelized flow erosion: as water moves over the surface of the area, some of it concentrates in low places to cut deeper channels. Continued flow results in miner channels (rills). After this, majör rills and large gullies may be formed.

Wind erosion:
If soil is dry, weakly aggregated, bare and smooth, wind erosion might ocur when wind speed is strong enough. Winds segregate dry humus, clay (0.002 mm in effective diamter), silt (0.05 mm in effective diameter), and sand (less than 2 mm in effective diameter). Some studies developed equations to predict soil erosion via wind triggered by traffic or material handling operations but I am not going to provide them here.

Ice erosion:
When ice is on the ground, there is no soil movement/deposition. However, when ice starts melting down, huge amounts of soil are deposited in low places/grounds. Glacial till is defined as unstratified, nonsorted materials deposited from melting glaciers and consisting of clay, silt, sand, gravel, and boulder type materials.

Gravity erosion:
Colluvium is name of material that is subject to downslope movement by gravity of weathered rock debris and sediments. Flow many be slow (solifluction) or rapid (mudflow). Some activity under this category occurs when relatively dry conditions are there.