River Environments
How rivers shape the landscape
River processes: **Erosion** (wearing away) — hydraulic action, abrasion, attrition, solution. **Transportation** — traction (rolling), saltation (bouncing), suspension (carried), solution (dissolved). **Deposition** — river slows, drops its load.
Landforms: Upper course: V-shaped valleys, waterfalls. Middle: **meanders** (erosion outer bend, deposition inner). Lower: **oxbow lakes** (cut-off meanders), **floodplains**, **deltas**.
Flooding causes: Physical: heavy rain, snowmelt, impermeable rock. Human: deforestation, urbanisation, building on floodplains.
Management: **Hard engineering:** dams, embankments, channel straightening. **Soft engineering:** floodplain zoning, afforestation, flood warnings.
Key Points to Remember
- 1River processes
- 2River landforms
- 3Flooding causes and management
- 4Water supply issues
Pakistan Example
The Indus River — Pakistan's Lifeline and Flood Risk
The Indus supplies the world's largest irrigation system. But monsoon floods devastate provinces — the 2022 floods submerged one-third of Pakistan, affecting 33 million. Physical causes (monsoon rain, clay soils) combined with human causes (deforestation, floodplain settlement).
Quick Revision Infographic
Geography — Quick Revision
River Environments
Key Concepts
The Indus River — Pakistan's Lifeline and Flood Risk
The Indus supplies the world's largest irrigation system. But monsoon floods devastate provinces — the 2022 floods submerged one-third of Pakistan, affecting 33 million. Physical causes (monsoon rain, clay soils) combined with human causes (deforestation, floodplain settlement).