A contour canal is an artificially-dug navigable
canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface fl ...
which closely follows the
contour line
A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional gra ...
of the land it traverses in order to avoid costly engineering works such as boring a
tunnel
A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...
through higher ground, building an embankment over lower ground, or constructing a
canal lock
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water lev ...
(or series of locks) to change the level of the canal. Because of this, these canals are characterised by their meandering course.
In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
, many of the canals built in the period from 1770 to 1800 were contour canals - for example, the
Oxford Canal
The Oxford Canal is a narrowboat canal in central England linking the City of Oxford with the Coventry Canal at Hawkesbury (just north of Coventry and south of Bedworth) via Banbury and Rugby. Completed in 1790, it connects to the River Tha ...
. Later canals tended to be much straighter and more direct - a good example is the
Shropshire Union Canal engineered by
Thomas Telford
Thomas Telford FRS, FRSE, (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotla ...
.
See also
*
Canals of the United Kingdom
The canals of the United Kingdom are a major part of the network of inland waterways in the United Kingdom. They have a varied history, from use for irrigation and transport, through becoming the focus of the Industrial Revolution, to today's r ...
*
Lingqu Canal
The Lingqu () is a canal in Xing'an County, near Guilin, in the northwestern corner of Guangxi, China. It connects the Xiang River (which flows north into the Yangtze) with the Li River (which flows south into the Gui River and Xijiang), ...
- the oldest contour canal in the world
Notes
References
*Day, Lance and Ian McNeil. (1996). ''Biographical Dictionary of the History of Technology''. New York: Routledge. {{ISBN, 0-415-06042-7.
Canals