waterfall

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Waterfall of a stream in Australia
Waterfall in the Auerbachtal in Bavaria

A waterfall is a section of flowing water ( river , brook ) where the flow, due to the formation of the rock bedrock , at least partially changes into free fall.

In the variety of shapes, the classic free, vertical fall is rather the exception. Most of the time there are sliding sections in the drop section, which are often transformed into stepped steps by forming pools . Depending on the steepness of the valley step , this can result in stair-like cascades or long series of several waterfalls.

Typical features of waterfalls

Rhine Falls , the largest waterfall in Europe in terms of volume flow

A typical waterfall combines the following features:

  • Significantly increased gradient to at least 100 percent (45 °; so the vertical component is larger than the horizontal)
  • Decay of the body of water and its partial detachment from the subsurface
  • Splash and white water are predominant (color effect due to light reflections at the air-water interfaces )
  • characteristic noise development
  • a microclimatic environment of its own

In the case of waterfalls, different sections can be distinguished:

  • Beginning of the fall section: possible transition area to the actual waterfall (see rapids )
  • Head zone: Area of ​​the waterfall above the fall zone, where the water changes from flowing through shooting into falling
  • Fall edge: possible clearly definable point in the head zone of the waterfall, where the water immediately changes from flowing to falling
  • Fall zone: Area of ​​the waterfall between the head and impact zone, where the water falls either freely, cascading or shooting (sliding)
  • Impact zone: Area of ​​the waterfall below the fall zone, where the falling, shooting or atomized water impacts and collects again to form a body of water (characteristics: wetness or high humidity, restricted vegetation)
  • Gump : mostly existing stilling basin in the impact zone of the waterfall with strong deep erosion
  • Outlet of the fall section - possible transition area to the normal watercourse, like a rapids with scouring .

A waterfall is a place of particularly active nature. Depending on its size, the water has different effects on its surroundings. The process structure of a waterfall can be described using, among other things

  • the energy turnover (water flow × height of fall)
  • the flow and friction processes (for example cavitation or ionization of the air ( ball electricity , colloquially called "waterfall electricity "))
  • the scour formation at the foot of the waterfall
  • the increased frost blasting on rocks in the spray area
  • the wind effect of the waterfall winds, a local wind system (radial wind), triggered by the downward movement of the falling water
  • the increased humidity

The natural occurrence of falling water is mainly the subject of research in physics (e.g. fluid mechanics ) and also in hydrology ; The history of its formation, i.e. the changes in the waterfall over time and its regularity, are the subject of geomorphology .

Concept and delimitation

Waterfall-like fountains ( Grugapark , Essen )

The general language , somewhat fuzzy term has lower limits for several characteristics of waterfalls:

  • if the altitude is too low, one speaks only of cataract ,
  • with too little gradient of rapids and
  • in the case of insufficient water flow from droplets or trickle falls. - See also the term veil fall in some places.

There are further delimitations for artificial waterfalls:

  • In the case of exclusive pumping, it is more a question of special well systems.
  • In the case of exclusively technical-functional design (chutes at dams , weirs ) the term waterfall is also not or no longer in use (see below for special cases ).

Conceptual special cases:

  • In the case of slope canals, sections flowing down the slope like a stream were referred to as waterfalls (example: upper part of the Nabental waterfall in the Harz Mountains).
  • The technical mill term waterfall was used to describe the gradient of the water that was concentrated on the weir and the mill wheel.
  • Sea Waterfall : Casual language game, refers to the situation in a short river between lakes.
  • Submarine waterfall : casual language game, refers to falling ocean currents, driven by differences in gravity caused by temperature or salinity .

An example of the difficult demarcation between waterfalls and rapids is the Sarpsfossen in Norway, which before the construction of the power plant had a drop of around 18 meters over a distance of a good 40 meters. Today only the lower natural fall section with a height of 12 meters is left. If you wanted to see it as a waterfall, as is customary in Norway, it would have been Europe's most powerful waterfall before the power plant was built with an average water flow of 577 m³ / s before Dettifoss and the Rhine Falls.

Origin and types

In general, a flowing water has the tendency to weaken gradient breaks and to develop a balanced longitudinal profile through retreating erosion and through its dragging load (transport of sand, gravel, etc.). This tendency opposes the formation of waterfalls, so that fall steps are only formed and maintained under special circumstances. There are two main types of case levels with subgroups:

  • Fall levels, which are caused by the flow dynamics of the body of water itself or to a large extent
Examples of destructive waterfalls formed by erosion processes
  • Waterfalls are particularly common in places where something that can be easily cleared follows beneath resilient rock . When the water crosses into the area where the softer rock spreads, an initial scouring creates a step with a gump and finally the undercutting of the harder rock. Over time, the rock breaks over this cavity. As a result, the position of the waterfall shifts upstream over time. This forming process is also called “retrograde erosion”. The most famous example is Niagara Falls . Many small cases of this type can be found, for example, in the south-west of Germany . The situation is similar in most cases in Iceland , where basalt ceilings act as fall builders.
Why a waterfall moves backwards as a result of scouring
  • Even in almost homogeneous rock such as granite or porphyry , ponds can form elegant cascade stairs over steps with pools, such as the Sieben Bütten . This also applies to cave waterfalls and one of their special forms, the glacier mills .
Examples of constructive waterfalls formed by mineral precipitation
  • Fall levels that are already given without any significant contribution from the flowing water
Examples of increasing or regenerating fall levels:
  • Waterfalls cascading down over the terrain of active faults. This can also include glacier mills that tumble down crevasses.
  • Waterfalls that plunge over surf cliffs into the sea ('bridal veil' near Seixal on Madeira , Kiel waterfall on Rügen )
  • Waterfalls from tributaries that cannot follow the stronger deep erosion of the receiving water and therefore fall down an estuary (Raumünzach waterfall in the Murgtal , waterfall of the Bornichbach on the Middle Rhine )
  • Waterfalls from tributaries, which flow over inclined slopes of receiving waters and therefore tumble down an estuary (Tannegger waterfall in the Wutach Gorge )
Examples of given, non-regenerating fall levels:
  • Valley steps , which were created by ice age glaciers (sometimes very high waterfalls, sometimes almost without their own reshaping of the rock step, sometimes with gorge or cascade formation )
  • Change from resistant to easily clearable rock or exposed change to loose material like at the Rhine Falls
  • Transversal fault joints with easily evacuated broken rock (Great Ravennafall in Höllental ) or large fissures (important factor in the detailed formation of falls, for example in the Triberg waterfalls )
  • Natural shortening of valley windings (mostly constriction of bound meanders or similar: shortening a tributary directly to the main river). Examples: Cirque de Navacelles in the Cevennes , Schischemklamm near Rottweil
  • Artificial abbreviations of watercourses (use of hydropower, flood protection, often only anticipation of expected natural development). Examples: Waterfalls of Coo and Elzbach waterfall near Pyrmont.
  • Returns from artificial feed lines to former hydropower plants (natural further formation of closed anthropogenic terrain forms). Examples: Spiegel Valley Waterfall in the Harz Mountains , Blauenthal Waterfall in the Ore Mountains
  • Artificial slope breaks through stone quarries in valley floors (natural further formation of closed anthropogenic terrain forms). Examples: Krenkinger waterfall in the Steina valley , Laubach falls in the Neandertal
  • Artificial waterfalls designed as such. Examples: Radau waterfall ; Waterfalls in the Bergpark Wilhelmshöhe in Kassel

There are numerous transitional and mixed forms between these types. For example, rounded longitudinal profiles of steep steps often occur in relief embossed in a glacial manner. Hanging valleys (side valley that flows high above the floor of a glacier-shaped trough valley) can very gradually merge into the wall of a trough valley and this in turn into the broad valley floor. The scouring only leads to a pronounced impact zone or a cascade-like sequence of steps in the head zone of the fall in the course of further deformation by the waterfall.

Icy waterfall on a rock face in the Rhön

Well-known waterfalls

Particularly high waterfalls
  • The greatest water gradient on earth is under water; on the Denmark Strait , the sea water flows down 600 meters below sea ​​level to 4000 meters.
  • The Salto Ángel in southeastern Venezuela plunges 978 meters from the table mountain Auyan-Tepui ; this makes it the highest single waterfall on earth. After the atomized water has collected again to form a river, it falls again over a steep step in the forest. Both falls together have a height of almost 1200 m (a few years ago a double fall with a total height of 1250 meters was discovered in southeastern Venezuela, which falls from the remote Marahuaca tepui).
  • The five-tiered Tugela Falls are located in the Royal Natal National Park in the South African province of KwaZulu-Natal and have a total height of 948 meters.
  • For a while after its discovery, the Peruvian gocta was considered the third highest waterfall on earth at 771 meters (double fall).
  • The three-part Yosemite Falls are located in Yosemite National Park and are known as the highest waterfalls in North America with a total height of 739 m.
Particularly wide waterfalls
  • The Iguazú Falls in South America, on the Iguazú River on the border between Brazil and Argentina , height: 72 m, mean flow: 1740 m³ / s, spread over a falling edge of 2700 meters in length.
  • The Victoria Falls of the Zambezi , between Zimbabwe and Zambia , form the largest "water curtain" in the world in February and March with a width of 1708 m and a fall height of 99 m. The mean flow rate is 1090 m³ / s, maximum approx. 9100 m³ / s.
  • The partly cataract-like Khone Falls of the Mekong form a fall front of around ten kilometers in length, divided by large islands.
Waterfalls particularly rich in water
  • The Khone Falls of the Mekong, with their fronts of around ten kilometers in length, divided by large islands.
  • The Dry Falls in Washington state are 5600 m wide and 120 m high and during the Missoula floods carried ten times the discharge of all rivers today. This makes them the largest known waterfalls in the history of the earth.
  • The Guaira Falls or Sete Quedas Falls of the Paraná were considered to be the largest waterfalls on earth by their volume until they were flooded in 1982 by the dammed water of the Itaipú Dam. A little later, the Brazilian government had it partially blown up to facilitate navigation on the reservoir. Any renaturation has thus been made impossible.
  • The Niagara Falls between the USA and Canada, height: up to 59 m, average flow: approx. 6000 m³ / s, are the water-richest falls in North America.
  • The Salto Pará of the Río Caura (tributary of the Orinoco ) is not only one of the widest waterfalls in the world with a drop edge that is interrupted several times and is a total of 64 meters high and around 5 kilometers long, but also one of the richest in water at around 3500 m³ / s.
  • The Cachoeira de Paulo Afonso of the Rio São Francisco falls 81 meters deep into a ravine with a water flow of around 2830 m³ / s (strong water withdrawal by a hydropower plant).
Waterfalls in Germany, Austria and Switzerland
  • In the Triberg waterfalls , the Gutach falls over two drop stairs of approx. 10 m and approx. 85 m height (with seven steps) into the Triberg valley basin. It is Germany's most famous waterfall, although with a total of 163 m it is not, as traditionally attested, its highest.
  • The Röthbachfall in Berchtesgadener Land am Obersee (near Königssee ) is the highest waterfall in Germany with a total height of 470 m and a pure drop height of 380 m, although visible from afar, it is difficult to reach.
  • The Krimml Waterfalls , a series of massive river waterfalls 140, 100 and 140 meters high, are considered the highest waterfalls in Austria.
  • The Mürrenbachfall with a height of 417 m, the highest waterfall in Switzerland.
  • The Serenbach Falls on Lake Walen are a three-stage cascade with a total of 585 m drop height, with the middle waterfall at 305 m being the second highest waterfall in Switzerland.
  • The Rhine Falls near Neuhausen in Switzerland are , next to Dettifoss in Iceland, the largest waterfall in Europe, height: around 22 m, mean flow: 373 m³ / s (mean flow in summer: approx. 700 m³ / s).
  • The 297-meter-high, free-tumbling Staubbach Falls has received numerous literary awards and has become known in particular through Johann Wolfgang von Goethe .
  • The Reichenbach Falls in Switzerland are a series of seven steps with a total height of 250 meters. They were best known through a scene in the final battle between Arthur Conan Doyle's fictional characters Sherlock Holmes and Professor Moriarty.
  • The Engstligen Falls near Adelboden have a total of around 370 m drop height with two main steps.
Well-known waterfalls in Europe
  • The Dettifoss of Jökulsá á Fjöllum , Iceland is next to the Rhine Falls, the largest waterfall in Europe, height: 44 m, mean flow rate: 193 m³ / s.
  • The Tännforsen in Sweden is only a little smaller . Depending on the season, 400 to over 750 m³ / s of water from Lake Tännsjön plunge 37 m deep into Lake Östra Noren.
  • The Gavarnie Falls in the Pyrenees are the highest waterfall in France with a drop of 422 m and are often referred to as the second highest waterfall in Europe.
  • The Vøringsfossen is a 183 m high waterfall in the Hardangervidda in Norway, directly on the Oslo – Bergen road.
Cataracts and rapids named as waterfall

Several so-called waterfalls can only be addressed as cataracts or rapids . Are known:

  • The Inga Falls are a 40 m high cataract stretch of almost ten kilometers in the course of the rapids, also known as Livingstone Falls, in which the Congo crosses the Lower Guinea Sill. With an average water flow of 41,000 m³ / s, they are by far the most important cataracts on earth.
  • The Boyoma Falls of the Lualaba , upper reaches of the Congo ( Democratic Republic of the Congo ) are a sequence of 7 cataracts up to 5 m in height, in which the river loses 60 m in height over a length of around 100 km (annual discharge: 17,000 m³ / s).

Ecological aspects

Waterfalls represent an obstacle for fish species migrating upstream, which can be overcome by species adapted to them (e.g. salmon ). That is why the Saynbach waterfall , for example , was eliminated in November 2008. In some places fish ladders are built to overcome smaller, especially artificially created, waterfalls and barrages .

In climatic areas with longer dry phases, island-like, humid habitats may have developed in the vicinity of larger waterfalls ; The area around the Victoria Falls is particularly known for this .

Cultural landscape aspects

Typical waterfall names

The names of waterfalls often refer to similar features and anomalies such as the dynamics of movement, the lighting effects and sounds or local myths. Conversely, the area can also be named after the waterfall. In the following, name examples are broken down according to typical references. Only references to the respective river, valley or nearby place are excluded.

Describing the movement and shape of the fall

  • Drommeler Sprötz (Eifel)
  • Geltenschuss (Switzerland)
  • Casting from Veringendorf (Swabian Alb)
  • Hochfall (Bavarian Forest)
  • Hoher Gießel (Swabian Alb)
  • Kühseich (Swabian layers; "Kuh-Pissstrahl")
  • Pfersag waterfall (Franconian Alb; pronounced "Pfersaach", meaning "horse piss jet")
  • Pisciadú (Dolomites; Ladin: "waterfall")
  • Pissevache (Rhone Valley; "cow piss ray")
  • Scheuche (Eichsfeld)
  • Schleierfalls (Alpine Foreland)
  • Seven fountains (South Tyrol)
  • Strahlbrusch (Southern Black Forest)
  • Stroll (Rothaar Mountains; "Pissstrahl", also called "Cold Spring")
  • Wasserbaum (Leinebergland)

Emphasizing or onomatopoeic the sound of the fall

  • Augrabies (South Africa; Khoisan / San: (Aukoerebis) "place of roaring noise")
  • Doos (Franconian Alb)
  • Elsachbröller (Swabian Alb)
  • Sounding waterfall (Franconian Alb)
  • The Rausch (Eifel)
  • Ruschbachfall (Southern Black Forest)
  • Thusfall (Fichtel Mountains)

Alluding to the spray and light effect

Describing or naming the topography

  • Bodekessel (Harz)
  • Büstenlochfall (Northern Black Forest)
  • Hangloch waterfall (southern Black Forest; Todtnauer waterfall)
  • Hollow stone (Swabian layers)
  • Höll waterfalls (southern Black Forest)
  • Hukou ( yellow river ; "pourer", "bottle neck")
  • Kammerloch Waterfalls (Northern Black Forest)
  • Cascade Gorge (Rhön)
  • Kiel waterfall (Rügen; Kiel: ridge in the tallow above)
  • Nineteen holes (Lahn-Taunus)
  • Ravennafall (Black Forest; reference to French "Ravin" for gorge)
  • Rissfalls (Vogtland; crack as a name for a slope canal)
  • Crack hole cases
  • Röllchen (Thuringian Forest; "Rillchen" for the small gorge)
  • Seven handmade paper (Black Forest; Allerheiligen waterfalls )
  • Steinerne Renne (Harz)
  • Stone Gully (Alpine Foreland)
  • Growing brook (Swabian layer levels)

Noise as a property of the stilling basin

  • Brusekessel (Lennegebirge)
  • Donnerloch (Hunsrück)
  • Krai Woog Gumpen (southern Black Forest; "Schreitümpel")
  • Rauschkümpel (Hunsrück)

Fall events as a property of the stilling basin

  • Schiessentümpel (Luxembourgish Switzerland)

The fall and its movement as a property of the fall wall

  • Plästerlegge (Rothaargebirge; "Plätscherschiefer")
  • Schießlay (Eifel; Klidinger waterfall)
  • Tear layer (Eifel)
  • Tretstein (South Rhön, "Trätsch-Stein")
  • Dripping Stone (Thuringian Forest)
  • Water rocks (Schwarzatal, southern Black Forest)

Fall events as a characteristic of the stream or valley

  • Falling brook (Odenwald)
  • Föllbachfall
  • Sturzdobel (Wutach Gorge)

Alluding to frightening effects

  • Höllenloch (Lahntal, also called forester's stairs)
  • Teufelskessel (southern Black Forest)
  • Trou de Fer (La Réunion; aka Trou d'enfer: "Hellhole")

Referring to culture, legends and events

  • All Saints Falls (Northern Black Forest)
  • Barnafoss (Iceland; reference to drowned children)
  • Dragoon jump (Swabian Alb)
  • Waterfalls at the Edelfrauengrab (Northern Black Forest)
  • Förstertreppchen (Lahntal, also called Höllenloch)
  • Hinkelskret waterfall (Saarland; "chick hideout")
  • Catherine Falls (Lake Constance)
  • Mermaid pond (Rhön)
  • Tanzlay (Eifel)
  • Tatzelwurm (Bavarian Alps)
  • Teufelsbadstube (Franconian shift levels)
  • Teufelsmühle (Rhön)
  • Teufelsmühle (Northern Black Forest)
  • Tusculum (Southern Black Forest)

Alluding to the impact of the case

  • Trout jump (Swabian layers)
  • Growing brook (Swabian layers)

Toponyms of the area related to the waterfall

  • Pisciadú (Northern part of the Sella in the Dolomites, based on the Pisciadú of the same name, Ladin: "waterfall")
  • Semonkong (small town in Lesotho; "place of smoke", based on the Maletsunyane waterfall)
  • Stübenbach (reference to the Todtnauer waterfall, southern Black Forest)
  • Waterfall (village in North Rhine-Westphalia, based on the Plästerlegge)

photos

See also

literature

  • TW Noyes: The Worlds Great Waterfalls. In: National Geographic Magazine . No. 50, 1926, pp. 29-59.
  • Martin Schwarzbach : Icelandic waterfalls and a genetic system of waterfalls in general. In: Journal of Geomorphology. NF Vol. 11, 1967, ISSN  0372-8854 , pp. 377-417.
  • RW Young: Waterfalls, Form and Progress. In: Journal of Geomorphology. Supplement. NF Vol. 55, 1985, ISSN  0044-2798 , pp. 81-95.

Web links

Wiktionary: Waterfall  - explanations of meanings, word origins, synonyms, translations
Commons : Waterfall  - album with pictures, videos and audio files
Wikiquote: Waterfall  Quotes

Individual evidence

  1. ↑ Florian Spichtig, Christian Schwick: Mürrenbachfall. In: Waterfall.ch. Retrieved June 26, 2012 .
  2. ↑ a b Julia Slater: Waterfalls: Which is the tallest in the whole country? In: swissinfo.ch. March 1, 2010, accessed May 26, 2012 .
  3. ↑ Florian Spichtig, Christian Schwick: Serenbach Falls. In: Waterfall.ch. Retrieved June 26, 2012 .
  4. ↑ a b Florian Spichtig: Where the water falls , Geosciences actuel 2/2007 (PDF; 3.4 MB)
  5. ↑ Florian Spichtig, Christian Schwick: Staubbachfall. In: Waterfall.ch. Retrieved June 26, 2012 .