Cossyimages Waterfall Collection
Waterfalls are commonly formed in the upper course of a river in steep mountains. Because of their landscape position, many waterfalls occur over bedrock fed by little contributing area, so may be ephemeral and flow only during rainstorms or significant snowmelt. The further downstream, the more perennial a waterfall can be. Waterfalls can have a wide range of widths and depths, and this diversity is part of what makes them such a charismatic and interesting natural phenomenon. Research into the diversity of natural waterfalls systematics has been carried out in recent years.