Differences between Persian qanats and Roman aqueducts A

Differences between Persian qanats and Roman aqueducts A short explanation and a comparisson by W. D. Schram MSc

Overview Introduction on Roman aqueducts Introduction about Persian qanats Comparison An example Differences Persian qanats and Roman aqueducts

Aqueducts: definition An aqueduct is a channel or pipeline to transport water over a greater distance, from a water source to its destination: often a city, sometimes a farm, factory or mill; there the water is distributed. Differences Persian qanats and Roman aqueducts

Aqueducts: basic elements Differences Persian qanats and Roman aqueducts

Aqueducts: tunnels A masonry channel inside a tunnel (Cave de Curé, Gier aqueduct, Lyon, France) Differences Persian qanats and Roman aqueducts

Aqueducts: bridges One of the bridges in an aqueduct of Perge (Turkey), fully covered with calcareous deposits Differences Persian qanats and Roman aqueducts

Aqueducts: arcade Two aqueduct channels (70 and 88 km long, mainly subterranean) on top of a series of arches (Rome, Italy) Differences Persian qanats and Roman aqueducts

Aqueducts: the users Local fountain (Gerasa, Jordan) Baths (reconstruction) (Xanten, Germany) Differences Persian qanats and Roman aqueducts

Roman aqueducts: some 1500 Differences Persian qanats and Roman aqueducts

Qanats: definition A qanat is a combination of - an infiltration gallery or mother well that collects water from an aquifer, and - an underground tunnel, connecting a series of vertical shafts, to transport water by gravity to the surface for direct consumption and / or irrigation. Differences Persian qanats and Roman aqueducts

Qanats: basic elements Differences Persian qanats and Roman aqueducts

Qanats: construction Muqanni Clay rings for reinforcements Differences Persian qanats and Roman aqueducts

Qanats: from the air Persepolis Differences Persian qanats and Roman aqueducts

Qanats: channel and shafts Qanat shaft (near Yazd) Shaft tops Differences Persian qanats and Roman aqueducts

Qanats: bridge One of the few qanat bridges. This one is from Kharanaq. Differences Persian qanats and Roman aqueducts

Qanats: distribution in Iran Differences Persian qanats and Roman aqueducts

Qanats: distribution worldwide Differences Persian qanats and Roman aqueducts

Qanats: in Europe ? ? A water supply system in Walferdange (Luxemburg) with a stepped channel and access shafts Differences Persian qanats and Roman aqueducts

Qanats: the users Place to scoop water Water distribution Differences Persian qanats and Roman aqueducts

Side step: water storage Water storage site Entrance Differences Persian qanats and Roman aqueducts

Comparison 1: Physical Geography Element Persian qanat Roman aqueduct 1 a. Character of the terrain Alluvial fans in mountainous areas From mountainous to almost flat area’s 1 b. Climate Mainly in arid regions Semi-arid and wet area’s 1 c. Source Mother well(s) in an aquifer External spring, river, lake; by exception a well or aquifer 1 d. Type of source Delayed delivery Mainly instant delivery 1 e. Place in the landscape 100% subterranean Some 20% above ground Differences Persian qanats and Roman aqueducts

Comparison 2: Technology Element Persian qanat Roman aqueduct 2 a. Construction Subterranean channel with shafts Masonry channel or pipe, sometimes with manholes 2 b. Builders Paid specialists / specialists Slave specialists, contractors, sometimes military personnel 2 c. Course Almost straight line Sinuous, following the countour lines 2 d. Works of art By exception (bridges, subterrenean dams and mills) Bridges, tunnels, arcades, siphons 2 e. Distribution Sluice gates, timesharing systems Castellae divisoria 2 f. Storage Only local, with modelst volumes No, behind some large bath houses 2 g. Surplus water Reused in other qanats at lower level Flushing sewers and public toilets, fullers Differences Persian qanats and Roman aqueducts

Comparison 3: Societal Element Persian qanat Roman aqueduct 3 a. Users Farmers and general public. By exception in private housing for cooling General public use and bathhouses. By exception industry, private individuals and farmers 3 b. Ownership In cooperation (10 – 250 individuals). Sometimes rich individuals Public bodies, town councils 3 c. Finance Members of the cooperation Locan maecenas, emporer, town council 3 d. Status within society The only water source, essential for life, utilitarian Additional to existing sources, luxury, showcase of pride and power 3 e. Present status Many still in use Almost all out of use, some reconstructed Differences Persian qanats and Roman aqueducts

Example: Hadrian’s aqueduct in Athens Differences Persian qanats and Roman aqueducts

Example The major factor applied to Hadrian’s aqueduct Element As with qanats H aq Source Aquifer(s) + Course Straight - See the map Users General public and farmers +/- General public and baths - City council Ownership Cooperation Status The only source of water Remarks Additionally to existing wells and springs Differences Persian qanats and Roman aqueducts

Conclusions Hadrian’s work had some elements in common with a typical qanat, but it was an aqueduct 2. In general: Although there are some similarities, qanats and aqueducts are quite different water supply systems 1. Why is this important? There is enough misunderstanding of the word qanat. Differences Persian qanats and Roman aqueducts

Problems ? ! Nonius Datus (150 CE) (Saldae, Algeria) Tehran (2009 CE) Differences Persian qanats and Roman aqueducts