Rivers – True or false

Waterfalls typically form in the upper course of a river where hard rock overlays soft rock. The river erodes the soft rock more easily, creating a steep drop. Over time, the waterfall erodes the soft rock beneath the hard rock, forming an overhang that eventually collapses. This cycle causes the waterfall to move upstream, leaving a gorge behind.

Where are true waterfalls typically formed?

• In the upper course of a river

• At the river delta

• In the middle course of a river

• In the lower course of a river

What causes the steep drop in the riverbed at a waterfall?

• The river changes direction

• The river deposits sediment

• The river erodes the soft rock more easily

• The river erodes the hard rock more easily

What happens to the overhang formed by the waterfall?

• It collapses under its own weight

• It turns into a bridge

• It moves downstream

• It becomes stronger over time

How does the waterfall affect the landscape over time?

• It creates a lake

• It forms a steep-sided gorge

• It creates a desert

• It flattens the terrain

What is the result of the waterfall moving upstream?

• The river becomes wider

• The river becomes shallower

• A gorge is left behind

• A mountain is formed