Waterfall

Lore & Background

Humans have had a distinct relationship with waterfalls since prehistory, traveling to see them, exploring and naming them. Waterfalls are religious sites in many cultures. Since the 18th century, they have received increased attention as tourist destinations, sources of hydropower, and particularly since the mid-20th century as subjects of research.

Reader's Guide

Waterfalls can be formed in several ways, but the most common method is that a river courses over a top layer of resistant bedrock before falling onto softer rock, which erodes faster, leading to an increasingly high fall. Natural waterfalls are commonly formed in the upper course of a river where lakes flow into valleys in steep mountains. A waterfall is generally defined as a point in a river where water flows over a steep drop that is close to or directly vertical. Some sources use a minimum height of 20 ft, while others define it as at least five feet high. There are various types including cascade, cataract, ledge, block, curtain, plunge, punchbowl, chute, fan, horsetail, ribbon, segmented, slide, tiered, and veil, among others.

Did You Know?

• Waterfalls can present formidable barriers to navigation along rivers.
• Waterfalls create a small microclimate characterized by cooler temperatures and higher humidity than the surrounding region.
• Some waterfalls are ephemeral and only flow after rain or significant snowmelt.
• Underwater waterfalls can form where cold, denser water overflows a cataract and sinks below warmer water.