Canal

From Wikipedia, the free encyclopedia

For other uses, see Canal (disambiguation).

Canals are man-made channels for water.

There are two main types of canals: irrigation canals, which are used for the delivery of water, and waterways, which are transportation canals used for passage of goods and people, often connected to (and sometimes connecting) existing lakes, rivers, or oceans.

This article deals primarily with artificial waterways (i.e. canals built primarily for transportation purposes).

1 Types of Artificial Waterways
2 Ancient canals
3 Cities on water
4 Industrial revolution
5 Modern uses
6 Gallery
7 Miscellaneous
8 Notes
9 Famous canals and lists
10 See also
11 External links

[edit] Types of Artificial Waterways

Some canals are part of a waterway which is not entirely artificial. This is usually where a river has been canalised : making it navigable by widening and deepening some parts (by dredging and/or weirs) and "cuts" around the weirs or other difficult sections. Smaller transportation canals can carry barges or narrowboats, while ship canals allow sea-going ships to travel from one sea or ocean to another, or to an inland port (eg Manchester Ship Canal, Caledonian Canal, Kiel Canal ).

The flight of 16 locks at Caen Hill on the Kennet and Avon Canal, Wiltshire, England

[edit] Ancient canals

The oldest-known canals were built in Mesopotamia circa 4000 BC. The Indus Valley Civilization in Pakistan and North India (from circa 2600 BC) had the first canal irrigation system in the world. The longest canal of ancient times was the Grand Canal of China. It is 1794 kilometers (1115 miles) long and was built to carry the Emperor Yang Guang between Beijing and Hangzhou. The project began in 605, although the oldest sections of the canal may have existed since circa 486 BC. Even in its narrowest urban sections it is rarely less than 30 m (100 ft) wide.

[edit] Cities on water

Canals are so deeply identified with Venice that many canal cities have been nicknamed "the Venice of..." The city is built on marshy islands, with wooden piles supporting the buildings, so that here it is not so much the waterways which are man-made, as the land. The islands have a long history of settlement, and by the 12th century Venice was a powerful city state.

Tourist boats, also known as canal-bus, in Amsterdam, Holland.

Amsterdam was built in a similar way, with buildings on wooden piles. The pace of draining of fenland and polder in the Low Countries quickened in the 14th century and canalization made the village of Amsterdam a port. It became a city around 1300.

Canal estates are a form of subdivision popular in cities like Miami, Florida and the Gold Coast, Queensland; the Gold Coast has over 700 km of residential canals. Wetlands are difficult areas upon which to build housing estates, so dredging part of the wetland down to a navigable channel provides fill to build up another part of the wetland above the flood level for houses. Land is built up in a finger pattern that provides a suburban street layout of waterfront housing blocks. This practice is not popular with environmentalists.

[edit] Industrial revolution

In Europe and then in the young United States, inland canals preceded the development of railroads during the earliest phase of the Industrial Revolution; some canals were later drained and used as railroad rights-of-way. Navigable canals reached into previously isolated areas and brought them in touch with the world economy. The Erie Canal, for instance, opened up a connection from the populated Northeast to the fertile Great Plains.

The Kennet and Avon Canal at Bathampton, near Bath, England

The oldest canal built for industrial purposes in North America is Mother Brook in Dedham, MA. It was constructed in 1639 to provide water power for mills. Lowell, Massachusetts, considered to be "The Cradle of the American Industrial Revolution," has 6 miles of canals, built from around 1790 to 1850, that provided waterpower and a means of transportation for the city.

Competition from the railway network made many canals obsolete for commercial transportation, and many fell into decay.

See also: History of the British canal system

[edit] Modern uses

A movement that began in Britain and France to use the early industrial canals for pleasure boats has spurred rehabilitation of stretches of historic canals.

Canals have found another use in the 21st century, as wayleaves for fibre optic telecommunications networks.

[edit] Gallery

Rio de la Verona: a rio or small canal in Venice	The Grand Canal of China at Suzhou	Amsterdam gracht (2007)	A picturesque stretch on the Calder and Hebble Navigation, England
The Pawtucket Canal during a flood of the Merrimack River at Lowell, Massachusetts	Map of Lowell's power canal system	The Miraflores Locks on the Panama Canal (2004)