Vannfalls

Vannfalls, commonly referred to as waterfalls, are features in rivers or streams where the water descends vertically or nearly so over a ledge or cliff. They form where a river encounters rock of differing resistance, or where relief changes due to uplift or erosion. Waterfalls vary widely in height, width, and volume.

Form and types: The appearance and behavior of a waterfall depend on rock type, slope, and flow. Common forms include plunge waterfalls, where water drops freely; horsetail waterfalls, where the flow maintains contact with the rock; cascades, which descend in a sequence of steps; punchbowl, tiered, and curtain falls.

Geomorphology and hydrology: Waterfalls erode at their base, forming plunge pools. Over time, undercutting and headward retreat move the lip upstream. Flow regimes—seasonal variation, rainfall, and snowmelt—shape the visible form and accessibility.

Ecology and human use: The mist and spray create localized habitats for mosses, ferns, and invertebrates. Waterfalls attract tourism and, in some places, provide hydroelectric power. They pose hazards such as slippery rocks, sudden floods, and rockfalls.

Notable examples: Angel Falls in Venezuela is often cited as the world’s tallest uninterrupted waterfall at about 979 meters. Niagara Falls (Canada–USA) is famous for its scale and power, with a height around 51 meters. Victoria Falls (Zambia–Zimbabwe) reaches about 108 meters. Iguazu Falls (Argentina–Brazil) comprises a large series of drops, and Yosemite Falls (United States) is one of North America’s tallest.