How river valley changes downstream

Question 1

upper course processes and landforms

Answer 1

• waterfalls
• potholes
• V-shaped valley
• River channel remains shallow & narrow
• not enough power to erode
• large angular boulders
• small discharge
• main form of transportation is traction

Question 2

middle course processes and landforms

Answer 2

• River has more energy due to tributaries & can erode laterally
• Gradient more gentle
• Wider & deeper river
• Can pick up lighter sediment ( saltation & suspension)
• Meanders creating floodplain
• Oxbow lakes
• Levees can build up either side of the river.

Question 3

meanders

Answer 3

• Outside bend –fast flowing abrasion & hydraulic action undercut bank & create river cliff
• Inside bend slower, material deposited, as more friction, slip-off slope.

Question 4

lower course processes and landforms

Answer 4

• Very wide
• Flat valley
• Large, deep channel
• Very small sediment ( suspension or solution)
• Floodplain
• Fast flowing, as channel smooth
• Deposition may take place
• Delta, river estuary at mouth, when speed reduced.