One man and his barrel (waterfalls) - see bottom of page
Formation of a waterfall:
Waterfalls occur near the start of the river where the rivers is running fastest.
There needs to be had rock overlying soft rock.
The soft rock is eroded more quickly as it is weaker than the hard rock.
The rocks swirl around at the base of the waterfall to create a plunge pool.
The waterfall continues to erode backwards to create a gorge
Some useful weblinks:
Video on how waterfalls are formed -
Video on waterfalls, plunge pool and potholes -
Why are rivers important?