Cycle of erosion
Also called: Geographical cycle, Davisian cycle · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
The cycle of erosion is an idea given by W.M. Davis in 1899. He said that once a landmass is uplifted, rivers slowly wear it down through three stages: youth, maturity and old age. The look of a landscape depends on three things: its structure (the rocks and how they lie), the process at work and the stage it has reached. The cycle ends in a peneplain, an almost flat plain. A few hard-rock hills called monadnocks still stand on it. If the land is uplifted again, or the sea level falls, the river starts cutting down again. This is called rejuvenation, and it restarts the cycle.
Example
The Aravalli range in Rajasthan is one of the oldest mountain ranges in India. It has been worn into low, rounded and broken hills. It shows how a landscape moves towards old age over a very long time.
Don't confuse with
- Penck's model (1924): Davis said uplift comes first and erosion follows. Penck said uplift and erosion work at the same time, so the shape of a slope shows how fast the land is rising.
Related concepts
- Landform
- Youth stage
- Mature stage
- Old stage
- Peneplain
- Monadnock
- Sheet erosion
- Lateral and vertical erosion