Waterfalls are one of the beautiful sights we see. We enjoy swimming through the water and experience cool and fresh water on our skin or simply view it from afar and wonder how waterfalls are formed. The formation of waterfalls may be hard to understand but as we grasp on the facts on how such magnificence are formed, it would be easier for us to comprehend all about the geological processes involved with its formation.
There are various types of waterfalls. The types are classified according to the course of waterfalls, the amount or volume of water that falls through it and the complex processes on how they are formed. The most common types of waterfalls we have are the cascade and cataract waterfalls.
The cascade waterfalls are those kinds that are made because of lesser water volume and those that have more irregularities on the water surface. On the other hand, cataract waterfalls are those formed with more volume of water, resulting to rapids. Aside from those mentioned, other types of waterfalls are ledge, slide, parallel, staircase and combination waterfalls.
When a watercourse passes through a hard rock or a soft rock, this marks the beginning of the geological processes of waterfall formation. Since water is an erosive agent, the rocks underneath such watercourse will move and the rate of its movement depends upon the type of rock. It is observed that hard rock erode slowly while soft rock erodes in faster speed.
Because soft rock erodes faster than hard rock, what happens here is that it is further cut through the watercourse. After significant erosion of soft rock, the hard rock is then hanging over the edge, making the watercourse steeper as seen through its vertical flow of water. When the water steepens, a plunge or cascades and rapids are formed at the same time. Thus, this is how waterfalls are formed.
However, the process is not over yet. As the watercourse continue to fall, the waterfall gets taller and its plunge deeper. This happens as a result of further undercutting of soft rocks up to the point of time wherein hard rock gets unstable. The hard rock is then carried by the river due to high pressure and the formation processes continues until the watercourse becomes a rapid or stream once more.
Another known way of waterfall formation is through glaciers. When glaciers are eroded through traversing downstream, this leaves a large-sized valley when glaciers melt. Then, the same geological processes of waterfall formation apply with those stated above.