SELF IMPROVEMENT #004

This only helps Cheryuen and I but..

CHAPTER 6 GEOGRAPHY - RIVER AND COASTS (RIVER PROCESSES)

1. Erosion occurs when rocks and other materials are broken into smaller pieces, and moved downstream by the energy of the river.

• Hydraulic action: fast moving water loosens and dislodges rocks and soil from the river bed and banks
• Corrasion: rock fragments are dragged along by the flow of water, grinding against the river bed and banks
• Attrition: eroded materials in the river constantly collide and break into smaller pieces
• Solution: minerals in rocks dissolve carbonic acid in river due to acid rain

2. Transportation occurs when materials are carried downstream by the energy of the river.

• Traction: larger sized particles roll and slide along river bed
• Saltation: materials transported downstream by bouncing movement
• Suspension: fine particles carried along river without touching river bed
• Solution: dissolved materials transported downstream

3. Deposition occurs when load is deposited due to insufficient energy of the river.

Factors causing deposition

• Low precipitation
• Decrease in speed
• Shallow channel, increased friction
• Sudden increase in load
• Obstructed by plants or protruding bed rocks