Some waterfalls form in mountain environments where the erosive water force is high and stream courses may be subject to sudden and catastrophic change. In such cases, the waterfall may not be the end product of many years of water action over a region, but rather the result of relatively sudden geological processes such as landslides, faults or volcanic action. In cold places in the winter snow will build up. And when summer come it melts and turns into a water fall

Formation

Streams become wider and more shallow just above waterfalls due to flowing over the rock shelf, and there is usually a deep pool just below the waterfall because of the kinetic energy of the water hitting the bottom.Waterfalls normally form in a rocky area due to erosion

Waterfalls can occur along the edge of glacial trough, whereby a stream or river flowing into a glacier continues to flow into a valley after the glacier has receded or melted. The large waterfalls in Yosemite Valley are examples of this phenomenon. The rivers are flowing from hanging valleys.

Classifying Waterfalls

Waterfalls are grouped into 10 broad classes based on the average volume of water present on the fall using a logarithmic scale. Class 10 waterfalls include Niagara Falls, Paulo Alfonso Falls and Khone Falls.

Classes of other well known waterfalls include; Victoria Falls and Kaieteur Falls (Class 9); Rhine Falls, Gullfoss and Sutherland Falls (Class 8); Angel Falls and Dettifoss (Class 7); Yosemite Falls and Lower Yellowstone Falls and Umphang Thee Lor Sue Water Fall Thailand (Class 6).

Types of waterfalls

• Block: Water descends from a relatively wide stream or river.
• Cascade: Water descends a series of rock steps.
• Cataract: A large, powerful waterfall.
• Fan: Water spreads horizontally as it descends while remaining in contact with bedrock.
• Horsetail: Descending water maintains some contact with bedrock.
• Plunge: Water descends vertically, losing contact with the bedrock surface.
• Punchbowl: Water descends in a constricted form, then spreads out in a wider pool.
• Segmented: Distinctly separate flows of water form as it descends.
• Tiered: Water drops in a series of distinct steps or falls.
• Multi-step: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool.