Thalweg
Encyclopedia
Thalweg in geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

 and fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...

 geomorphology
Geomorphology
Geomorphology is the scientific study of landforms and the processes that shape them...

 signifies the deepest continuous inline within a valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

 or watercourse
Watercourse
A watercourse is any flowing body of water. These include rivers, streams, anabranches, and so forth.-See also:* physical geography* Environmental flow* Waterway* Hydrology* Wadi-External links:...

 system.

Hydrology

In hydrological
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...

 and fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...

 landforms, the thalweg is a line drawn to join the lowest points along the entire length of a stream bed
Stream bed
A stream bed is the channel bottom of a stream, river or creek; the physical confine of the normal water flow. The lateral confines or channel margins, during all but flood stage, are known as the stream banks or river banks. In fact, a flood occurs when a stream overflows its banks and flows onto...

 or valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

 in its downward slope, defining its deepest channel. The thalweg thus marks the natural direction (the profile) of a watercourse. The thalweg is almost always the line of fastest flow in any river.

The term is also sometimes used to refer to a subterranean stream that percolates under the surface and in the same general direction as the surface stream.

Real world application

Slowing stream bed erosion by taking advantage of a thalweg helps stabilize running water sources. Placing boulders along the thalweg in a running water source helps to protect the channels sedimentary erosion and deposit balance. In concurrence with the placement of boulders along a thalweg, the placement of boulders along an instream to form man-made sills also helps to slow the sedimentary erosion and deposit of running water sources. While in-turn keeping the esteem (Fishing, Local Wildlife, and Recreation) and natural resources of the running water source intact. The placement of boulders along a thalweg and the creation of instream sills help to aid the flow of water during late summer months when the flow rate drops, and helps to slow sedimentary erosion and deposit in the spring and fall months when the flow rates are high. This process of utilizing a thalweg to slow stream bed erosion was used in Meacham Creek, Umatilla, Oregon (1990).

Thalweg principle

The thalweg principle is the principle in which the boundary
Border
Borders define geographic boundaries of political entities or legal jurisdictions, such as governments, sovereign states, federated states and other subnational entities. Some borders—such as a state's internal administrative borders, or inter-state borders within the Schengen Area—are open and...

 between two political states separated by a watercourse is denoted as the thalweg of that watercourse, if those two states have agreed to use the thalweg definition. Various states have also defined their watercourse international boundaries by a median line, left bank, right bank, etc.

The precise drawing of river boundaries has been important on countless occasions; notable examples include the Shatt al-Arab (known as Arvand Rud in Iran) between Iraq and Iran, the Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

 in central Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, the Kasikili/Sedudu
Kasikili
Kasikili Island, or Sedudu Island , is an island in the Chobe River on the border between Namibia and Botswana, near the Botswanan town of Kasane. It was the subject of a territorial dispute between these countries, resolved by a 1999 decision of the International Court of Justice which ruled in...

 Island dispute between Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

 and Botswana
Botswana
Botswana, officially the Republic of Botswana , is a landlocked country located in Southern Africa. The citizens are referred to as "Batswana" . Formerly the British protectorate of Bechuanaland, Botswana adopted its new name after becoming independent within the Commonwealth on 30 September 1966...

, settled by the International Court of Justice
International Court of Justice
The International Court of Justice is the primary judicial organ of the United Nations. It is based in the Peace Palace in The Hague, Netherlands...

 in 1999 http://www.icj-cij.org/docket/index.php?case=98&p1=3&p2=1&p3=6&pr=318&search=%22botswana%22, and the 2004 dispute settlement under the UN Law of the Sea
Law of the sea
Law of the sea may refer to:* United Nations Convention on the Law of the Sea* Admiralty law* The Custom of the Sea...

 concerning the offshore boundary between Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

 and Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...

, in which the thalweg of the Courantyne River
Courantyne River
The Corentyne / Courantyne / Corantijn River is a river in northern South America in the country of Suriname, it is the longest river in the state. The river originates in the Acarai Mountains and flows northward for approximately between Guyana and Suriname, emptying into the Atlantic Ocean near...

 played a role in the ruling.

Etymology

Thalweg is an English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 loan word from German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

. The German word Thalweg (nowadays spelt Talweg) is a compound noun that is built from the German elements
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 Thal (since Duden
Konrad Duden
Konrad Alexander Friedrich Duden was a Gymnasium teacher who became a philologist. He founded the well-known German language dictionary bearing his name Duden.- Life :...

's orthography reform of 1901
German orthography
German orthography, although largely phonemic, shows many instances of spellings that are historic or analogous to other spellings rather than phonemic. The pronunciation of almost every word can be derived from its spelling, once the spelling rules are known, but the opposite is not generally the...

written Tal) meaning valley, and Weg, meaning way.

External links



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