QUAESTIONES GEOGRAPHICAE 39(1) • 2020 WATERFALLS: FORMS, DISTRIBUTION, PROCESSES AND RATES OF RECESSION ANDREW S. GOUDIE School of Geography, Centre for the Environment, University of Oxford, Oxford, United Kingdom Manuscript received: December 15, 2019 Revised version: February 2, 2020 GOUDIE A. S., 2020. Waterfalls: forms, distribution, processes and rates of recession. Quaestiones Geographicae 39(1), Bo- gucki Wydawnictwo Naukowe, Poznań, pp. 59–77. 8 figs, 3 tables. ABSTRACT: A waterfall is a very steep (commonly nearly vertical) fall of some magnitude in a river course. Waterfalls are widespread fluvial landforms that have been described from many parts of the world. Thirty-eight World Heritage Properties include waterfalls in their designation. In addition, some waterfalls are actual or potential geomorphosites. Waterfalls occur in almost all climatic environments, though they are particularly common in formerly glaciated areas. They occur on a huge diversity of rock types, although in general, they do not form persistent or large falls on soft or unconsolidated rocks. Waterfalls also occur in a wide range of geomorphological settings: glaciated areas, areas of ac- tive tectonism, areas of sea-cliff retreat and sea-level change, great escarpments on passive margins, basins with river capture, rifted and faulted areas and areas that have been subjected to megaflooding. Multiple processes account for waterfall retreat and varying rates of recession. Although the greatest interest has been in rates of waterfall recession, there are examples of waterfalls that prograde as a result of tufa deposition. KEY WORDS: waterfalls, caprock, knickpoints, plunge pools, tufa Corresponding author: Andrew Goudie,
[email protected] Introduction distribution and rates of retreat.