- 2066 Bhadra (old course) · 2 marks
Landslide versus debris flow
Short answer
A landslide slides as a coherent mass along a distinct slip surface with low to moderate water content. A debris flow moves like a viscous fluid with very high water content, no distinct slip surface, and deposits as a lobate fan.
Differentiate between landslide and debris flow.
| Point | Landslide (slide) | Debris flow |
|---|---|---|
| Movement | Sliding as a mass along a slip surface | Flows like a viscous fluid |
| Material | Rock, soil or debris | Saturated mixture of water, soil, gravel and boulders |
| Water content | Low to moderate | Very high (above liquid limit) |
| Speed | Slow to rapid | Rapid to very rapid |
| Slope | Moderate to steep | Steep channels, deposit on the gentle fan |
| Slip surface | Distinct | No distinct surface; the whole mass deforms |
| Trigger | Rain, earthquake, cutting | Intense rainfall, flash floods, landslide dam |
| Deposit | Hummocky body | Lobate fan and levees |
✓ Answer checked by Claude Opus 5.5 (high effort)
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