Persian qanats and Roman aqueducts

A short explanation and a comparissonby W.D. Schram MSc

Overview

Introduction on Roman aqueductsIntroduction about Persian qanatsSpecial topicsComparison

Persian qanats and Roman aqueducts

Aqueducts: basic elements


Aqueducts: tunnel

Note: a masonry channel

inside a tunnel (Cave de Curé, Gier aqueduct, Lyon, France)


Aqueducts: bridges

The world known aqueduct bridge Pont du Gard, part of the aqueduct (50 km) of Nimes (France).

Also represented on a banknote of 5 euro


Aqueducts: arcade

Two (!) aqueduct channels (70 and 88 km long, mainly subterranean) on top of a series of arches (Rome, Italy)


The Roman empire


Aqueducts: some 750


Aqueducts: the usersLocal fountain (Gerasa, Jordan)

Baths (reconstruction)(Xanten, Germany)


Aqueducts: examples

Tunnel and pipes Akcay tunnel(550 BCE) (Side, Turkey) (Samos, Greece)

Water distribution(Pompeii, Italy)


Qanats: basic elements


Qanats: channel and shaftsQanat shaft (near Yazd) Shaft tops


Qanats: from the air

Persepolis


Qanats: the users Place to scoop water Water distribution


Qanats: works of artQanat bridge (Kharanaq, Yazd)

Ice house(Yazd)


Qanats: distribution worldwide


Qanats: distribution 1


Qanats: distribution 2Tehran (ca 1960 CE) Isfahan (1942 CE)


Qanats: distribution 3Tafilalt (Maroc) Qanats in Syria


Qanats: in Europe 1Madrid (Spain) = Madjira = place of qanats

Near Selb and Asch (Germany)


Qanats: in Europe 2The qanat of Walferdange (Luxemburg) with stepped channel and access shafts


Qanats: construction

Muqanni Clay rings for reinforcements


Storage Water storage site Entrance


CoolingWind towers Technique


Ice house Meybod Cross-section


Subterrenean damDam in a qanat (Vazvan) Cross-section


Subterranean water mill

Horizontal water wheel


Comparison 1Element Iranian qanat Roman aqueduct

Climate Mainly in arid regions In arid and semi-arid regions

Source Aquifer River, spring or dam (by exception: well or aquifer)

Place in the landscape

100% subterranean 20% above ground (arcades, substructions)

Construction Shafts every 50 – 100m plus connecting channel

Masonry channel (or pipe), sometimes in qanat construction (shaft every 35 – 70 m)

Course Straight line Sinuous, following the contour lines

Works of art Exceptional: subterranean dams

Bridges, tunnels, arcades, siphonsPersian qanats and Roman aqueducts


Users Public and farmers (private houses, bath houses?)

Public and bathhouses. Also: houses, farmers, ornamental fountains (grainmills)

Distribution Channels and sluices; for irrigation timesharing

Distribution stations plus lead pipes inside the towns

Status Utilitarian / lifeline Additional to other sources (wells, rainwater); luxury (Baths); showcase (Show of pride and power)

Builders Well paid specialists Slave specialist, contractors, sometimes support from the military

Ownership Coorperative ( 10 – 250 p)

Town councilPersian qanats and Roman aqueducts


Finance Members of the cooperation

Local meacenas, the emperor, twon council

Surplus water (only in winter): ? To flush the sewers and toilets, fullers

Storage Local in modest volumes

No, only behind some large bath houses (e.g. Rome)

Basics: - cross-section - typical length - typical discharge - typical depth - typical fall

0,6 – 1,2 m10 km2.000 m3/day10 – 50 m0,07 – 0,1 %

0,6 – 1,2 m20 km20.000 m3/day5 m0,1 – 0,5 %


Conclusions

Although there are similarities, qanats are quite different from roman aqueducts

Most striking: the difference in the sourcesqanat(s) are often the only source of waterRoman aqueducts are all out of use


Problems ?!Tehran (2009 CE)Nonius Datus (150

CE) (Saldae, Algeria)


Usefull websites

The International Center on Qanats and Historic Hydraulic Structures (ICQHS) in Yazd: http://www.icqhs.org/English/Default.aspx

The Water Museum in Yazd is part of the ICQHSYoutube film about qanats:

http://www.youtube.com/watch?v=ieBVMOPRYJ0


Thank you Wilke Schram

Persian qanats and Roman aqueducts

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