Module 6: Wind Erosion Flashcards
What is the process of wind erosion?
Wind erosion occurs in four steps;
1. Dislodging
2. Entrainment
3. Transportation
4. Deposition
What are the causes of wind erosion?
What are the effects of wind erosion on soil functions?
What is the difference between potential and actual wind erosion?
Potential wind erosion takes in account the hypothetical risk of wind erosion based on soil type and climate (windy or not). Actual wind erosion is the potential wind erosion but takes into account land management and agricultural practices. This because those determine how vulnerable the local soil is to erode.
Which soils are likely to erode? How is this linked to arid and semi-arid regions?
Bare, flat, loose, fine, dry, sandy soils. In arid and semi-arid regions the risk for soil erosion is higher. Okay
What are the forces that cause entrainment?
- Upward suction: soil particles are lifted from the surface
- Drag forces: soil particles are rolling/sliding along the surface
- Bombardement: soil particles landing on the soil cause other particles to move.
What is a threshold velocity?
The velocity at which soils particles are loose and become dislodged.
What are the modes of transport in wind erosion?
- Creep; one to several meters
- Saltation; long keeping soil particles
- Suspension; fine particles are moved over high altitudes
What is reptation?
When landing soil particles cause other soil particles to bounce up and move.
What is erosivity?
The available energy of the wind.
What is erodibility?
The resistance of the soil particles to the wind.
What is the roughness of a landscape? Does it affect soil of wind related factors?
Elements such as trees and buildings that break up the landscape. It decreases the erosivity.
How does erosivity relate to air humidity?
Higher air humidity results in a lower erosivity compared to wind with lower humidity. Above 80% air humidity, the risk of wind erosion is very low.
What is a nursing crop?
A nursing crop is a quick growing crop, sown just before the main crop, to protect the main crop against wind erosion until the main crop provides a good ground cover.
