Types of erosion

• What processes occur in a river?

  Erosion, transportation, and deposition
• How do the rates of erosion, transportation, and deposition change in a river?

  They change from the upper course to the lower course
• What is erosion in the context of rivers?

  • The process that wears away the river bed and banks
  • Breaks up rocks carried by the river
• What are the four types of erosion in rivers?

  Hydraulic action, abrasion, attrition, and solution
• What is hydraulic action?

  The sheer power of water smashing against river banks
• How does hydraulic action affect river banks?

  It compresses air in cracks, releasing it explosively
• What is abrasion in river erosion?

  When pebbles grind along the river bank and bed
• What occurs during attrition?

  Rocks carried by the river knock against each other
• What is solution in the context of river erosion?

  When water dissolves certain types of rocks, like limestone
• What is weathering?

  • The breaking down of rocks in situ
  • Caused by weather, plants, animals, and chemical processes
• How does weathering relate to river basins?

  It also breaks down rocks in river basins