WATERFALL

A waterfall is a place where water flows over a vertical drop or a series of steep drops in the course of a stream or river. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf.
Alexander von Humboldt (1820s) “Father of Modern Geography” Humboldt was mostly marking waterfalls on maps for river navigation purposes.

Oscar von Engeln (1930s) Published “Geomorphology: systematic and regional”, this book had a whole chapter devoted to waterfalls, and is one of the earliest examples of published works on waterfalls.

R. W. Young (1980s) Wrote “Waterfalls: form and process” this work made waterfalls a much more serious topic for research for modern Geoscientists

Types:
Ledge waterfall: Water descends vertically over a vertical cliff, maintaining partial contact with the bedrock.[11]
Block/Sheet: Water descends from a relatively wide stream or river.[5][11]
Classical: Ledge waterfalls where fall height is nearly equal to stream width, forming a vertical square shape.[5]
Curtain: Ledge waterfalls which descend over a height larger than the width of falling water stream.[5]
Plunge: Fast moving water descends vertically, losing complete contact with the bedrock surface.[11] The contact is typically lost due to horizontal thrust of the water before it falls. It always starts from a narrow stream.
Punchbowl: Water descends in a constricted form and then spreads out in a wider pool.[11]
Horsetail: Descending water maintains contact with bedrock most of the time.[11]
Slide: Water glides down maintaining continuous contact.[11]
Ribbon: Water descends over a long narrow strip.[11]
Chute: A large quantity of water forced through a narrow, vertical passage.[11]
Fan: Water spreads horizontally as it descends while remaining in contact with bedrock.[11]
Cascade: Water descends a series of rock steps.[5][11]
Tiered/Multi-step/Staircase: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool.[11]
Cataract: A large, powerful waterfall.[11]
Segmented: Distinctly separate flows of water form as it descends.[11]
Frozen: Any waterfall which has some element of ice or snow.[11]
Moulin: A moulin is a waterfall in a glacier