A mechanism for raising or lowering ships in a river that has rapids or waterfalls is called dam and lock system. It is a special kind of dam system.
A lock is the mechanism for raising and lowering ships in a river that has rapids or waterfalls. Locks are used to make navigation an easier task.
That's called an accidental sign.
There are no waterfalls on the river Thames.
A step like series of waterfalls are called a cataract
A Botanist is a person who studies plants but also studies waterfalls.
Potamophobia - Is the fear of running water. There isn't one specifically for waterfalls.
precipitatiopn
Rapids
Dk
Fall Line
Fall Line
waterfalls