How Waterfalls are Classified
There are many different systems for the classification of waterfalls. After examining a number of these and desiring to keep it simple, we have settled on the following system because it is quite relevant to the geology of the Niagara Escarpment and the waterfalls along the escarpment.
If you look at the various websites that feature waterfalls along the Niagara Escarpment, you will see a variety of different classifications. It's not that any of these classifications are wrong, it's just that the classification is based on different criteria. Unfortunately not everyone states these criteria
We have settled on the two criteria listed below: the size and shape of the waterfall and the rock formation of the falls. These two seem to fit very well with the waterfalls found along the escarpment on Southern Ontario although a broader system would be needed to go beyond this area.
1) Classification based on the size and shape of the waterfall
- Ribbon - The height of the waterfall is notably greater than the crest width
- Classical - The height and crest are nearly equal in size
- Curtain - The width is notably greater than the height
- Plunge - The water plunges over a cliff face created when a hard layer of horizontal bedrock is above softer eroding rock below. The water descends vertically with little contact with the surface.
- Terraced - Unlike plunge waterfalls, terraced falls do not have a prominent hard rock layer at the top. The water drops in a series of distinct steps or falls.
- Cascade - The bedrock under a cascade tends to be more irregular than the plunge or terraced falls classification.
- Complex - A waterfall which includes features of more than one type of waterfall. It could plunge from the top and then halfway down, cascade the rest of the way. This is a type of catch-all phrase for more difficult to classify falls.
2) Classification based on the rock formation of the falls
As a result most of our names for the types of the waterfalls are compound terms that take in account both criteria. So you will see names like "curtain plunge" or "ribbon cascade". Sometimes a complex falls can be better described by taking two terms from the rock formation such as "complex cascade".