In Southeastern Nigeria, gully erosion poses a severe environmental hazard. What is the correct sequential order of the stages in the development of a gully, from initial land disturbance to catastrophic collapse?
- 1Removal of protective vegetative cover through land clearing, road construction, or deforestation.
- 2Concentration of unhindered surface runoff carving micro-channels known as rills on bare slopes.
- 3Deepening and widening of rills into incised channels through continuous hydraulic scouring.
- 4Under-cutting of gully bases and groundwater seepage causing massive wall failure and land loss.
Cevap
The correct sequence begins with vegetation removal, followed by surface runoff forming micro-rills, which deepen into incised gullies, and culminates in massive sidewall collapse and severe structural land loss.
The erosion process follows a logical morpho-dynamic progression: human or natural land clearing first removes protective vegetation, allowing concentrated surface runoff to carve rills. Continuous concentrated water flow deepens these rills into gullies, which eventually undergo mass failure and sidewall slumping due to basal under-cutting and sub-surface seepage.
Adım Adım Çözüm
Anahtar Kavram
Stages of Gully Erosion Process
Tahmini Süre:1m 15s