Aqueduct (water supply)
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An aqueduct is a
Etymology
The word aqueduct is derived from the Latin words aqua (water) and ductus (led or guided).
Ancient aqueducts
Although particularly associated with the Romans, aqueducts were devised much earlier in Greece, the
Crete
Although particularly associated with the
Deccan
The Indian subcontinent is believed to have some of the earliest aqueducts. Evidence can be found at the sites of present-day
Oman
In
There are three types of falaj:
- Daudi (داوودية) with underground aqueducts
- Ghaili (الغيلية ) requiring a dam to collect the water
- Aini (العينية ) whose source is a water spring
These enabled large scale agriculture to flourish in a dry land environment.
Persia
In
- taps into subterranean water in a manner that delivers water to the surface without the need for pumping. The water drains relied on gravity, with the destination lower than the source, which is typically an upland aquifer.
- allows water to be transported long distances in hot dry climates without losing a large proportion of the source water to seepage and evaporation.
Petra, Jordan
Throughout
Greece
On the island of Samos, the Tunnel of Eupalinos was built during the reign of Polycrates (538–522 BC). It is considered an underground aqueduct and brought fresh water to Pythagoreion for roughly a thousand years.
Roman
Roman aqueducts were built in all parts of the Roman Empire, from Germany to Africa, and especially in the city of Rome, where they totalled over 415 kilometres (258 mi). The aqueducts supplied fresh water to public baths and for drinking water, in large cities across the empire, and set a standard of engineering that was not surpassed for more than a thousand years. Bridges, built in stone with multiple arches, were a distinctive feature of Roman aqueducts and hence the term aqueduct is often applied specifically to a bridge for carrying water.[1]
South America
Near the Peruvian town of Nazca, an ancient pre-Columbian system of aqueducts called Puquios were built and are still in use today. They were made of intricately placed stones, a construction material widely used by the Nazca culture. The time period in which they were constructed is still debated, but some evidence supports circa A.D. 540–552, in response to drought periods in the region.[6]
The Guayabo National Monument of Costa Rica, a park covering the largest archaeological site in the country, contains a system of aqueducts. The complex network of uncovered and covered aqueducts still functions well.[7] The aqueducts are constructed from rounded river stones, which are mostly made of volcanic rock.[8] The civilization that constructed the aqueduct system remains a mystery to archaeologists; it is suspected that Guayabo's aqueducts sat at a point of ancient cultural confluence between Aztecs, Mayans, and Incas.
North America
When Europeans saw the
Sri Lanka
Extensive usage of elaborate aqueducts have been found to have been used in ancient Sri Lanka. The best example is the Yoda Ela or Jaya Ganga, an 87 kilometres (54 mi) long water canal carrying excess water between two artificial reservoirs with a gradient of 10 to 20 cm per kilometer during the fifth century AD. However, the ancient engineering methods in calculating the exact elevation between the two reservoirs and the exact gradient of the canal to such fine precision had been lost with the fall of the civilization in 13th Century.[9]
Modern aqueducts
The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. (July 2012) |
Modern aqueducts are a central part of many countries' water distribution infrastructure.
The United States' aqueducts are some of the world's largest. The
An aqueduct in New Zealand, "the Oamaru Borough Race", was constructed in the late 19th century to deliver water (and water-power) about 50 km from the Waitaki River at Kurow to the coastal town of Oamaru.
In Spain, the Tagus-Segura Water Transfer system of aqueducts opened in 1979 and transports water 286 kilometres (178 mi) from north to south.[10]
In China, the South–North Water Transfer Project aims to connect the Yangtze River basin to Beijing through three separate systems. The project will reuse part of the Grand Canal of China.
Design
Open channels
The simplest aqueducts are small ditches cut into the earth. Much larger channels may be used in modern aqueducts, for instance the Central Arizona Project uses 7.3 m (24 ft) wide channels.[11] A major factor in the design of all open channels is its gradient. A higher gradient allows a smaller channel to carry the same amount of water as a larger channel with a lower gradient, but increases the potential of the water to damage the aqueduct's structure. A typical Roman aqueduct had a gradient of about 1:4800.[12]
Artificial rills
A constructed functional rill is a small canal or aqueduct of stone, brick, concrete, or other lining material, usually rectilinear in cross section, for water transportation from a source such as a river, spring, reservoir, qanat
Rills were traditionally used in
Rills are also used for aesthetic purposes in landscape design. Rills are used as narrow channels of water inset into the pavement of a garden, as linear water features, and often tiled and part of a fountain design.
The historical origins are from
Tunnels
Aqueducts sometimes run for some or all of their path through tunnels constructed underground. A version of this common in North Africa and Central Asia that has vertical wells at regular intervals is called a qanat. One historic example found in Syria, the Qanat Firaun, extends over 100 kilometers.[13]
Pipes
Modern aqueducts may also make extensive use of pipelines. Pipelines are useful for transporting water over long distances when it needs to move over hills, or where open channels are poor choices due to considerations of evaporation, freezing, pollution, or environmental impact. They can also be used to carry treated water.
Uses
Historically, agricultural societies have constructed aqueducts to irrigate crops. Archimedes invented the water screw to raise water for use in irrigation of croplands.
Another use for aqueducts is to supply large cities with drinking water. They also help drought-prone areas with water supply. Some of the Roman aqueducts still supply water to Rome today. In California, United States, three large aqueducts supply water over hundreds of miles to the Los Angeles area. Two are from the Owens River area, and a third is from the Colorado River.
In modern civil engineering projects, detailed study and analysis of open-channel flow is commonly required to support flood control, irrigation systems, and large water supply systems when an aqueduct rather than a pipeline is the preferred solution.
In the past, aqueducts often had channels made of earth or other porous materials but significant amounts of water are lost through such unlined aqueducts. As water gets increasingly scarce, these canals are being lined with concrete, polymers, or impermeable soil. In some cases, a new aqueduct is built alongside the old one because it cannot be shut down during construction.
See also
- Acequia
- Zanja
- Qanat
- Earthquake engineering
- Goldfields Water Supply Scheme
- Leat
- List of aqueducts
- List of canal aqueducts in the United Kingdom
- List of Roman aqueduct bridges
- Navigable aqueduct
- Pipeline– some used to carry water
- Roman architecture
- Roman engineering
- Sanitation in Ancient Rome
- Water resources
Notes
- ^ a b c "Aqueduct". Britannica (CD ed.). 2000.
- ^ Jacobsen, Thorkild; Lloyd, Seton (1935), Sennacherib's Aqueduct at Jerwan (PDF), University of Chicago Press, Oriental Institute Publication 24
- ^ Says, Alessiobrugnoli (23 July 2019). "Advanced water management and pioneer hydraulic technology in Minoan Crete (Bronze Age)". Novo Scriptorium. Retrieved 30 January 2022.
- ISBN 9788120601253.
- ^ Remini, B.; Kechard, R.; Achour, B. (2014-12-01). "THE COLLECTING OF GROUNDWATER BY THE QANATS: A MILLENNIUM TECHNIQUE DECAYING". Larhyss Journal (20): 259–277.
- ^ Zurich Puquios revised (PDF), U Mass
- ISBN 9781569756966.
- .
- ^ "Sri Lanka Tourism - the Official Website of Sri Lanka Tourisms".
- ^ Claver, José Manuel (27 October 2015). "El río que nos une" (Opinion). El Pais. Retrieved 8 February 2016.
- ^ "Request Rejected".
- ^ Mays, L. (Editor), Ancient Water Technologies, Springer, 2010. p. 119
- ^ Schulz, Matthias (11 March 2009). "Rome's Tremendous Tunnel: The Ancient World's Longest Underground Aqueduct". Spiegel Online.
References
- Sextus Julius Frontinus, De Aquaeductu Urbis Romae (On the water management of the city of Rome), Translated by R. H. Rodgers, 2003, University of Vermont
- Chanson, H. (2002). Certains Aspects de la Conception hydrauliques des Aqueducs Romains. ('Some Aspect on the Hydraulic Design of Roman Aqueducts.') Journal La Houille Blanche, No. 6/7, pp. 43–57 (ISSN 0018-6368)
- Chanson, H. (2008). "The Hydraulics of Roman Aqueducts: What do we know? Why should we learn?" in Proceedings of World Environmental and Water Resources Congress 2008 Ahupua'a, ASCE-EWRI Education, Research and History Symposium, Hawaii, USA, Invited Keynote lecture, 13–16 May, R.W. Badcock Jr and R. Walton Eds., 16 pages (ISBN 978-0-7844-0976-3)
Further reading
- Aicher, Peter J. 1995. Guide to the aqueducts of ancient Rome. Wauconda, IL: Bolchazy-Carducci.
- Beltrán Lloris, Francisco. 2006. "An irrigation decree from Roman Spain: The Lex Rivi Hiberiensis." Journal of Roman Studies 96: 147–97.
- Bruun, Christer. 1991. The water supply of ancient Rome: A study of Roman imperial administration. Helsinki: Societas Scientiarum Fennica.
- Coulton, J. J. 1987. "Roman aqueducts in Asia Minor." In Roman architecture in the Greek world. Edited by Sarah Macready and Frederick Hugh Thompson, 72–84. London: Society of Antiquaries.
- Frankel, R. 2002. "The Hellenistic aqueduct of Akko-Ptolemais." Journal of Roman Archaeology (Supplementary Studies) 46: 82–87.
- Grewe, Klaus. 2008. "Tunnels and canals." In The Oxford handbook of engineering and technology in the classical world. Edited by John Peter Oleson, 319–36. Oxford: Oxford Univ. Press.
- Hodge, A. Trevor. 1992. Roman aqueducts and water supply. London: Duckworth.
- Lewis, Michael Jonathan Taunton. 2001. Surveying instruments of Greece and Rome. Cambridge, UK, and New York: Cambridge Univ. Press.
- Wilson, Andrew I. 1999. "Deliveries extra urbem: Aqueducts and the countryside." Journal of Roman Archaeology 12: 314–32.
- --. 2008. "Hydraulic engineering and water supply." In The Oxford handbook of engineering and technology in the classical world. Edited by John Peter Oleson, 337–68. Oxford: Oxford Univ. Press.