Falls

Falls is a term that can refer to natural waterfalls or to the act of falling. In geography, a waterfall is a point in a river or stream where the water drops vertically or over a resistant rock layer, often forming a pool at the base. The term also appears in place names and in discussions of safety and injury.

Formation and geology: Waterfalls form where a river crosses layers of rock with differing resistance to erosion, or where a river drops into a zone of more resistant rock. Over time, erosion undercuts the lip, causing the water to plunge. Tectonic uplift and river capture can create new falls.

Classification and examples: Waterfalls are classified by shape, planform, and movement. Common types include plunge (water free-falls vertically), horsetail (water maintains contact with bedrock), cascade (water descends over a series of steps), and tiered or multi-step falls. Notable examples include Niagara Falls on the US-Canada border, Victoria Falls on the border of Zambia and Zimbabwe, Iguazu Falls on the Argentina-Brazil border, and Angel Falls in Venezuela, the highest uninterrupted waterfall.

Falls as injuries and safety: An accidental fall is a common cause of injury, particularly among older adults and in workplaces. Risk factors include balance impairment, hazards, and slippery surfaces. Prevention includes physical activity to improve strength and balance, home safety measures, use of assistive devices, and appropriate footwear.