How was Niagara falls formed?
The formation of Niagara falls began at the end of the ice age. Large, heavy flows of water were released from the melting ice, these flows of water then drained into what is now known as the Niagara river. About 12,000 years ago the water plunged over the edge of the Niagara escarpment (a escarpment is a long, steep slope).
Hydrolic action and abrasion also took part in making Niagara falls. They are used when the water is very powerful and contains lots of energy this picks up other materials and goes into deposition.
Positive effects of tourism.
negative effects on tourism.