The main components of a waterfall are water and a drop in height.
The way that the drop in height occurs provides the shape or style to the waterfall, some are cascades, or a series of steps where water is running out and over from one layer to the next. Some are in the form of a curtain, where the water comes over a flat piece of rock or some rocks at about the same height and has a sudden drop providing a curtain like effect. Spouts are where you have a flow of water coming out of a single trough or groove over a drop and can give an arc effect in some cases. Varying from the bubbling brook down a hillside to the massive falls like Niagara, there are many forms it can take.
Cascading Waterfall at Aysgarth Falls, Yorkshire
Sudden drops occur where the top layer of rock is harder than the layer below, and this softer under layer cuts back more, and the formation of a plunge pool under it, often causing the weaker soft rocks to collapse.
Waterfalls can be picturesque without being spectacular or large, perhaps involving the setting, while many listed as particularly large are difficult to both see and to photograph and when you do are uninteresting.
So while we may like to classify waterfalls in many ways and perhaps look at some as the largest by one classification or another, we should also look at the opportunities presented by others, including small ones we come across that may not be on maps and if seasonal may not have been photographed before or documented anywhere.
In addition to the waterfalls we find in nature, we also find some made by man, ether as the result of other work, for example maintaining the water level in a river or canal, or as an attraction or other feature.
When we have a sudden storm, and particularly when there are flash floods, temporary or unusual waterfalls may be formed that exist for only a short period, like some within mountain ranges such as the Brecon Beacons in Wales. While in many valleys, and woodlands we may find streams or rivers with their waterfalls that are only present after heavy rain.
Classifying and Identifying
Another way waterfalls are measured is by height, and you find many waterfalls in each country each said to be the highest in the country. This occurs as there are a number of ways to measure them, including the largest single fall, and total height of the combined steps. In some places several waterfalls close together may be treated as separate and in others as a part of the same falls. Many are groups of falls.
A third way some waterfalls are measured is by their width. Like with the height you can get a difference in opinions as to the method of measuring width, especially when there is more than one fall, so for example Niagara Falls has 3 elements - the Horseshoe or Canadian Fall, the American Falls and a smaller one in between, and you could measure the set from one side to the other, or measure the component parts and add them together missing the sections in between.
There is no grading system according to how well you can see or photograph them and no complete index or directory of all waterfalls. There are several websites that have partial indexes, often of the more major falls with other examples from some or all countries, usually without any more information than a name.
The naming of waterfalls is also problematic, some have a number of names, perhaps after the river, the gorge, the nearest village or town, or a local name. In some cases they will have both an English and local language name. Some you will come across, when travelling, are named after the first European to document them, and some then renamed by Governments or other bodies. The only way often to identify if it is the same or a different waterfall is from the map or grid reference.
We could also list them in many other ways including:-
But the most impotent list to each of us, is which are we gong to photograph and when.
Spout Waterfall as found at Hardraw Force, Yorkshire
See Also the Waterfalls Section for more articles on waterfalls and how to photograph them as well as links to listings of them by country and individual locations guides.