Thalweg
Encyclopedia : T : TH : THA : Thalweg
Thalweg (a German word compounded from Thal (nowadays spelled Tal), valley, and Weg, way) is a term adopted into English usage for geography and geomorphology. It signifies the line of greatest slope along the bottom of a valley, i.e. a line drawn through the lowest points of a valley in its downward slope. It thus marks the natural direction (the profile) of a watercourse.
The thalweg principle is the principle of determining national boundaries at the thalweg of a river separating two states. The precise drawing of river borders has been important on countless occasions; notable examples include the Arvandrud/Shatt al-Arab between Iraq and Iran, and the Danube in central Europe.
A thalweg in geology is a line representing the profile of a land surface, drawn as a series of cross-sections that crosses all contour lines at right angles.
The word thalweg is also used in hydrology. It refers to a line drawn to join the lowest points along the entire length of a streambed or valley. This is occasionally called a valley line. 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.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.