The Slope Retreat Model of L.C. King is one of those topics in Geomorphology that UPSC loves to test because it sits right at the intersection of Davis, Penck, and modern slope evolution theories. Many aspirants confuse it with Penck’s slope replacement model or Davis’ cycle of erosion. Let’s fix that clearly.
Contents
- 1 What Is L.C. King’s Model?
- 2 Inspiration Behind L.C. King’s Model
- 3 Core Concept: Parallel Slope Retreat (Backwasting)
- 4 Key Elements of L.C. King’s Landscape
- 5 Stages of L.C. King’s Cycle of Pediplanation
- 6 Climatic Uniformitarianism: A Unique Idea
- 7 L.C. King vs Davis vs Penck (Quick Recall)
- 8 Why This Model Is Important for UPSC
- 9 Check out our GS Geography Course – Click Here
- 10 FAQs
What Is L.C. King’s Model?
L.C. King proposed the slope retreat or backwasting model, mainly applicable to savanna, arid, and semi-arid regions.
This model is also known as:
- Epigene Cycle
- Cycle of Pediplanation
- Savanna Cycle of Erosion
- (sometimes) Arid / Semi-arid Cycle
👉 In UPSC answers, always mention “cycle of pediplanation” to signal conceptual clarity.
Inspiration Behind L.C. King’s Model
King did not reject earlier theories outright. Instead, he selectively borrowed from them.
From William Morris Davis
- Concept of cycle and time as a factor
- Youth–Mature–Senile stages
- Normal cycle of erosion
- Initial rapid upliftment followed by erosion
- Crustal stability and unidirectional development
👉 Difference:
- Davis’ normal cycle → humid temperate regions
- King’s normal cycle → savanna / semi-arid South Africa
From Walther Penck
- Importance of slope evolution
- Idea that slope change occurs from the base upward, not top-down
- Recognition of uplift (though subdued in King’s model)
However, King rejects Penck’s slope replacement and instead argues for parallel slope retreat.
Core Concept: Parallel Slope Retreat (Backwasting)
The most defining feature of L.C. King’s model is parallel retreat of slopes.
What does this mean?
- Slope angle remains constant
- Slope length remains constant
- Slopes retreat horizontally backward, not by becoming gentler
This happens due to:
- Presence of steep vertical scarp faces
- Strong river erosion and basal sapping
👉 This is why the model is also called the backwasting model.
Key Elements of L.C. King’s Landscape
According to King, any landscape under this model has three essential elements:
- Vertical Scarp Face
- Absolutely critical
- King clearly states: without scarps, his model cannot operate
- Pediment
- Gently sloping, almost flat surface at the foothills
- Formed by lateral erosion and slope retreat
- Inselbergs
- Residual hills standing above pediments
- Unlike Davis’ monadnocks, inselbergs appear early, not only at the senile stage
Stages of L.C. King’s Cycle of Pediplanation
Like Davis, King also talks about three stages, but with important differences.
1. Youthful Stage
- Dominant vertical river erosion
- Formation of nick points
- Initial development of small pediments
- Inselbergs appear early
2. Mature Stage
- Vertical erosion declines
- Lateral erosion dominates
- Valleys widen
- Pediments expand
- Inselbergs begin to reduce in size
3. Senile Stage
- Landscape becomes extensively flattened
- Formation of a wide pediplain
- Inselbergs are almost eliminated
👉 End product is pediplanation, not peneplanation.
Climatic Uniformitarianism: A Unique Idea
One controversial idea proposed by King is climatic uniformitarianism.
- King argues that similar landforms develop under all climates
- Climate only affects the rate, not the type, of landform development
- This directly contradicts Penck, who stressed climatic control
UPSC often tests this as a criticism of King’s model.
L.C. King vs Davis vs Penck (Quick Recall)
| Aspect | Davis | Penck | L.C. King |
|---|---|---|---|
| Role of time | Very important | Secondary | Important |
| Climate | Uniform | Climatically controlled | Climatic uniformitarianism |
| Slope change | Downwearing | Slope replacement | Parallel slope retreat |
| End product | Peneplain | No fixed end | Pediplain |
| Region | Humid temperate | Variable | Savanna / semi-arid |
Why This Model Is Important for UPSC
Frequently asked in Geography Optional
- Ideal for comparative questions
- Rich in technical terms (scarp, pediment, pediplanation)
- Easy to score with well-labeled diagrams
Check out our GS Geography Course – Click Here
FAQs
- #LCKingSlopeRetreatModel: What is L.C. King’s slope retreat or backwasting model in geomorphology?
- #PediplanationCycleUPSC: Why is L.C. King’s model called the cycle of pediplanation?
- #ParallelSlopeRetreat: How is parallel slope retreat different from Penck’s slope replacement model?
- #SavannaCycleOfErosion: What are the stages of L.C. King’s savanna cycle of erosion?
