F.5 GCE AS-level - Unit 1.3c - Plenary

Which of the following landform features can be found in the upper course of rivers?

• Waterfalls

• Floodplain

• Plunge pools

• Levees

• Gorges

Which of the following conditions may lead to the formation of waterfalls?

• Two layers of rock with different levels of resistance

• • Water flowing over a plateau edge

• Water flowing over a coastal cliff

• Water flowing over a hanging valley

• Water flowing over a fault scarp

Reorder the following statements to explain the formation of waterfalls.

• Water flows over a step in the river’s profile and erodes vertically downwards through hydraulic action and abrasion.

• Undercutting occurs, creating an overhang of rock. Water spills over the overhang, eroding a deep plunge pool through cavitation.

• Undercutting continues until the overhang is unsupported and collapses.

• This process is repeated over and over, and the waterfall retreats upstream, leaving behind a steep-sided gorge.

• The collapsed material is eroded through attrition and transported downstream, and also increases the abrasion of the plunge pool.

Which of the following descriptions about the landform feature showing in the photos are correct?

• The pool formed at the bottom is called a 'plunge pool'.

• When waterfalls retreat, gorges will be formed.

• Vertical cliffs can be found.

• Large body of water can be found.

• Abrasion and hydraulic action can be found.

Put the correct label in the diagram.

a

b

c

d

g

Overhang

Traction

Suspension

Abrasion

More resistant rock

Attrition

Solution

Hydraulic action

Less resistant rock