Waterfall

A waterfall is a section of a stream ( river, stream ) at which the flow through the formation of the rock subsoil, at least partially merges due in free fall.

In the variety of the forms of classical free vertical fall is rather the exception. Mostly there are sliding sections in the drop section, which are often deformed by the formation of pools in stage paragraphs. Depending on the steepness of the valley slopes can it step-like cascade or far constant sequences of several waterfalls occur.

Typical features of waterfalls

An ideal-typical waterfall combines the following features:

• Significantly increased gap at least 100 percent (45 °, so that the vertical component is greater than the horizontal )
• Decay of the water body and its partial detachment from the substrate
• Spray and white water are predominant ( color effect by light reflections at interfaces air - water)
• Characteristic noise
• A micro- climatic environment in his own right

With waterfalls, various sections can be distinguished:

• Beginning of the fall distance: possible transitional area to the actual waterfall ( cf. rapids )
• Head zone: the area of the waterfall above the fall zone, where the water goes from flowing over the shooting into traps
• Case edge: possible clearly defined place in the top zone of the waterfall, where the water from flowing directly into the traps changes
• Falls area of the waterfall between the head and the impact zone where the water either free, cascade or shooting ( sliding): fall zone
• Impact zone: the area of the waterfall below the fall zone, where the falling, shooting or atomized water and bouncing back to a body of water collects (features: moisture or high humidity, limited vegetation)
• Outlet of the drop section - possible transition region to the normal watercourse, stream quickly like with erosions.

A waterfall is a place particularly active events in nature. Depending on the size of the water acts differently strong one on its environment. The process structure of a waterfall can be described using, among other

• Of energy turnover ( water management × height of fall )
• ( called, for example, cavitation, or air ionization ( Balloelektrizität, colloquially "waterfall electricity" ) ) of the flow and friction processes
• The scour at the base of the falls
• The increased frost damage on rocks in Gischtbereich
• The wind effect the waterfall winch, a local wind system (radial wind ) caused by the downward movement of the falling water
• The increased humidity

The natural occurrence of the falling water is predominantly subject of research in physics (eg fluid mechanics ) and hydrology; shaping the story, so the changes of the waterfall over time and their regularities, are the subject of geomorphology.

Concept and definition

The general language, somewhat vague term has on several features of waterfalls limitations:

• At too low a level one speaks only of cataracts,
• At too shallow of rapids and
• In case of low water levels of drop veils or Rieselfällen.

Further selections can be found at artificial waterfalls:

• When used exclusively pumping operation, it is rather special fountain area.
• In exclusively technical- functional design ( shot gutters used in dams, weirs ), the term waterfall is also not or no longer used (see below for special cases).

Conceptual special cases:

• In slope channels like a stream flowing sections were HANGAB as a waterfall called (example: upper part of the hub Taler waterfall in the resin).
• With the mill technical term waterfall which focused on the military and on the water wheel slope of the water body has been designated.
• Sea Waterfall: Casual language game, refers to situation in a short river between lakes
• Undersea waterfall: Casual language game refers to falling sea currents

Origin and Types

Generally, a river has a tendency to weaken by headward erosion and its towing freight ( transport of sand, gravel, etc. ) gradient fractions and form a balanced longitudinal profile. This trend is contrary to the form of waterfalls, so as to form and maintain case levels only in special circumstances. There can be two main types of case levels differ with subgroups:

• Case levels, which are themselves caused or significantly influenced by the flow dynamics of the water body with limited

• Waterfalls form very often where under tough rock slightly ausräumbares follows. At the crossing of the water in the area where the softer rock crosses out, arises from an initial scouring stage with a Gumpe and finally the undermining of the harder rock. Over this cavity breaks with time after the rock. The location of the waterfall moves upstream by the passage of time. This shaping process is called also " headward erosion ". The most famous example is the Niagara Falls. Very many small cases of this kind can be found, for example, in the South German cuesta. Similarly, in most cases, Islands, where basalt act as Fallbildner.

• In almost homogeneous rocks such as granite or porphyry may result from scour through stages with pools shapely cascade stairs forms such as the Seven handmade paper. This also applies to cave waterfalls and one of its special form, the potholes.

• Waterfalls that build up due to carbonate precipitation at first small incline levels ( local pressure drop at the edge case ) gradually. The terrace edges of travertine ( tufa also called ) can reach up to 100 m altitude, particularly abundant in karst areas. Examples are the Plitvice lakes, the Urach waterfall or, as the largest of these waterfalls, the Huangguoshu waterfall in China. Also at the Stone -gutters waterfalls can form.

• Case levels that are already given without significant intervention of the watercourse

• Waterfalls, cascading over terrain stages active faults. For this one can also include potholes, rush down the crevasses.
• Waterfalls that cascade down the cliff into the sea surf ( ' Bridal Veil ' at Seixal in Madeira, Kiel waterfall on Rügen)
• Waterfalls of tributary streams that can not follow the stronger low erosion of the receiving water and therefore a mouth step down plunge ( Raumünzacher waterfall in the Murg valley, Waterfall of Bornichbaches the Middle Rhine )
• Waterfalls of tributary streams that flow through the baffle slopes of receiving waters and therefore a mouth step down plunge ( Tannegg waterfall in the Wutachschlucht )

• Levels of the valley caused by glacial glacier ( sometimes very high waterfalls, sometimes almost without his own reshaping of the rock step, sometimes with gorge or cascading )
• Change from resistant to easy ausräumbarem rock or exposed to exchange loose materials such as the Rhine Falls
• Transverse end warp joints with easy ausräumbarem fractured rock ( Big Ravenna case in the Hell Valley ) or large clefts ( important factor in the case of Detailausformung stages, for example in the Triberg Waterfalls )
• Natural abbreviate Talwindungen (mostly pinch- bound meanders or similar: abbreviation of a side stream directly to the main flow). Examples: Cirque de Navacelles in the Cevennes, Schlichemklamm in Rottweil
• Artificial abbreviations of watercourses ( hydropower, flood protection, often only anticipation of expected natural development). Examples: Waterfalls of Coo and Elzbach waterfall near Pyrmont.
• Recoiling from artificial feeds to former hydroelectric power plants ( natural extension forming closed anthropogenic landforms ). Examples: Spiegelthaler waterfall in the Harz Mountains, Blue Thaler waterfall in the Ore Mountains
• Artificial gradient fractions by quarries in valley bottoms ( natural extension forming closed anthropogenic landforms ). Examples: Krenkinger waterfall in the valley of Steina, Laubachfälle in the Neander Valley
• As such, designed artificial waterfalls. Examples: Radau waterfall; Waterfalls in the mountain park of Kassel Wilhelm

Between these types there are numerous transitional and mixed forms. For example, come in glaziär embossed relief often before rounded longitudinal sections of steep steps. Hanging valleys ( valley, which on the bottom of a glacier shaped trough valley opens high) can gradually pass into the wall of a trough valley, which in turn wide to the valley floor. The cratering leads only in the course of further rejuvenation by the waterfall to a pronounced impact zone or in a cascade-like sequence of stages in the head zone of the case.

Known Waterfalls

• The Angel Falls in southeastern Venezuela crashes from Table Mountain Auyán - Tepui 978 feet in depth; making it the highest single waterfall in the world. After the atomized water has collected back to a river, it rushes over a steep cliff in the forest again into the depths. Both cases have together even almost 1200 m drop height ( Some years ago, even a double case was discovered with an overall height of 1250 meters in the southeast of Venezuela, which rushes from the remote Marahuaca - Tepui ).
• The five -stage 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.
• The Peruvian Gocta was some time after its discovery a few years ago with 771 meters height (double case ) as the third highest waterfall in the world.
• The three-piece Yosemite Falls located in Yosemite National Park and are designated with a total height of 739 m as the highest waterfalls in North America.

• The Iguazu Falls in South America, the Iguazu River on the border between Brazil and Argentina, height: 72 m, Medium flow: 1740 m³ / s, spread over an edge case of 2700 meters in length.
• The Victoria Falls of the Zambezi River between Zimbabwe and Zambia, form in February and March the largest " water curtain " of the world with a width of 1708 m and a height of 99 m. The mean flow rate is 1090 m³ / s, a maximum of approximately 9100 m³ / s
• The part only cataract -like Khone Falls of the Mekong form a split by large islands case front of about ten kilometers in length.

• The Khone Falls of the Mekong with its split by large islands case front of about ten kilometers in length.
• The Dry Falls in Washington state are 5600 m wide and 120 m high and led ten times the runoff of all rivers existing today during the Missoula Floods. They are the largest known waterfalls in the Earth's history.
• The Guaira Falls or Sete Quedas cases of Paraná were considered the greatest according to their volume waterfalls on earth until they were flooded in 1982 by the dammed waters of the Itaipu Dam. A little later the Brazilian government let them blow up partially, so that the navigation was facilitated on the reservoir. Thus, any restoration has been made ​​impossible.
• The Niagara Falls between U.S. and Canada, Height: up to 59 m, Medium flow: 6000 m³ / s, the water-rich cases in North America are.
• The Salto Pará the Caura River ( tributary of the Orinoco ) has a number of interrupted case edge of a total of 64 meters in height and about 5 kilometers in length not only one of the widest waterfalls in the world, but with approximately 3500 m³ / s also one of the most water.
• The Cachoeira de Paulo Afonso of the São Francisco River plunges 81 meters into a gorge at a water flow of around 2830 m³ / s (severe dehydration through a hydroelectric power plant ).

• In the Triberg Waterfalls Gutach crashes on two case stairs of approximately 10 m and 85 m height ( seven steps) in the Triberg basin. It is Germany 's most famous waterfall, though not, as traditionally certified a total of 163 m, its highest.
• The Röthbachfall in Berchtesgaden on the Upper Lake ( near Koenigssee ) can be reached with about 470 m and 380 m total pure case is the tallest waterfall in Germany, though far visible, but difficult.
• The Krimml waterfalls, a consequence massive river waterfalls of 140, 100 and 140 meters above sea level, are the highest waterfalls in Austria.
• The Mürrenbach is with a height of 417 meters, the highest waterfall in Switzerland.
• The Serenbachfälle on Lake Walen is a three-stage cascade with a total of 585 m head, the middle waterfall with 305 meters is the second highest waterfall in Switzerland.
• The Rhine Falls in Neuhausen, Switzerland is next to the Dettifoss in Iceland is the largest waterfall in Europe, height: 22 m, Medium flow: 373 m³ / s (mean flow in summer: 700 m³ / s).
• The 297 -meter-high free swooping Staubbachfall has been frequently honored literary and became known especially by Johann Wolfgang von Goethe.
• The Reichenbach Falls in Switzerland are a series of seven stages with a total of 250 meters. They were known by a scene of the final battle between Arthur Conan Doyle's fictional characters Sherlock Holmes and Professor Moriarty.
• The Engstligen at Adelboden have two main steps in total to around 370 m drop height.

• The Dettifoss the Jökulsá Fjöllum, Iceland is next to the Rhine Falls largest waterfall in Europe, height: 44 m, average flow: 193 m³ / s
• The Tännforsen is only slightly smaller Vattenfallet in Sweden. Overthrow Depending on the season 400 to 750 m³ / s of water of the lake Tännsjön 37 m meters deep into the lake Östra Noren.
• The Gavarnie Falls in the Pyrenees with 422 m drop height of the tallest waterfall in France and are often dubbed as the second highest waterfall in Europe.
• The Vringsfossen is a 183 m high waterfall in the Hardangervidda in Norway, located directly on the street Oslo-Bergen.

Several so-called waterfalls are to speak only as cataract or rapids. Is known:

• The Inga Falls are a 40m-high cataract distance of about ten kilometers in the course of also Livingstone cases referred rapids, in which Congo crosses the low threshold Guinea. With a water channel in the middle of 39,000 m³ / s they are by far the most significant cataracts of the earth.
• The Boyoma Falls of the Lualaba, the headwaters of the Congo (Democratic Republic of Congo) are a series of seven cataracts up to 5 m height at which the flow 60 m height at around 100 km in length loses (annual runoff means: 17,000 m³ / s).

Ecological aspects

Waterfalls provide for upstream migrating fish species is an obstacle that can be ( eg salmon ) overcome by the adapted thereto species. To overcome smaller, especially artificial, waterfalls and dams fish in some ways be established.

Pictures

Waterfall in Caracol, Brazil

Boti Falls, Ghana Eastern Region, at low water, here are stilling basin and subsurface erosion can be clearly seen.

Waterfall in Africa

Atlantic: Madeira, North Coast ( "Bridal Veil " )

Blackwater Falls, West Virginia

Purakaunui Falls, New Zealand

Dettifoss, Northeast Iceland

Kreealmwasserfall in the Grossarl in Austria

Agua Azul, Chiapas