Formation of gullies
- Gully develops by several processes,
- Scouring at bottom and sides by flowing water
- Amount and nature of abrasive materials of flow
- Soil particles and debris with the flow
- Waterfall erosion at gully head
- Landslides, mass movements into the gullies from sides
- Alternate thawing and freezing
- Size varies from narrow and 2-3ft deep to 30-40 ft deep and 75 to 100 ft wide
- Shape: U or V shaped (V shaped occurs when subsoil is resistant to erosion
- Generally, the quantity of erosion yield is dependent upon the ability of rain to detach the soil particles (i.e., erosivity of rainfall) and at the same time the susceptibility of soil to withstand against the raindrop (i.e., erodibility of soil).
- Thus, the soil erosion is the function of both erosivity and erodibility.
- When rainfall erosivity exceeds the soil erodibility, soil erosion occurs.
