a short explanation and a comparisson by w.d. schram msc
TRANSCRIPT
Overview
Introduction on Roman aqueductsIntroduction about Persian qanatsComparison 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: 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 usersLocal fountain (Gerasa, Jordan)
Baths (reconstruction)(Xanten, Germany)
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: construction
Muqanni Clay rings for reinforcements
Differences Persian qanats and Roman aqueducts
Qanats: channel and shaftsQanat 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: 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
Comparison 1: Physical Geography
Element Persian qanat Roman aqueduct
1a. Character of the terrain
Alluvial fans in mountainous areas
From mountainous to almost flat area’s
1b. Climate Mainly in arid regions Semi-arid and wet area’s
1c. Source Mother well(s) in an aquifer
External spring, river, lake; by exception a well or aquifer
1d. Type of source Delayed delivery Mainly instant delivery
1e. Place in the landscape
100% subterranean Some 20% above ground
Differences Persian qanats and Roman aqueducts
Comparison 2: TechnologyElement Persian qanat Roman aqueduct
2a. Construction Subterranean channel with shafts
Masonry channel or pipe, sometimes with manholes
2b. Builders Paid specialists / specialists Slave specialists, contractors, sometimes military personnel
2c. Course Almost straight line Sinuous, following the countour lines
2d. Works of art By exception (bridges, subterrenean dams and mills)
Bridges, tunnels, arcades, siphons
2e. Distribution Sluice gates, timesharing systems
Castellae divisoria
2f. Storage Only local, with modelst volumes No, behind some large bath houses
2g. Surplus water
Reused in other qanats at lower level
Flushing sewers and public toilets, fullers
Differences Persian qanats and Roman aqueducts
Comparison 3: SocietalElement Persian qanat Roman aqueduct
3a. Users Farmers and general public. By exception in private housing for cooling
General public use and bath-houses. By exception industry, private individuals and farmers
3b. Ownership In cooperation (10 – 250 individuals). Sometimes rich individuals
Public bodies, town councils
3c. Finance Members of the cooperation Locan maecenas, emporer, town council
3d. Status within society
The only water source, essential for life, utilitarian
Additional to existing sources, luxury, showcase of pride and power
3e. Present status Many still in use Almost all out of use, some reconstructed
Differences Persian qanats and Roman aqueducts
ExampleThe major factor applied to Hadrian’s aqueduct
Differences Persian qanats and Roman aqueducts
Element As with qanats
H aq Remarks
Source Aquifer(s) +
Course Straight - See the map
Users General public and farmers
+/- General public and baths
Ownership
Cooperation - City council
Status The only source of water
- Additionally to existing wells and springs
Conclusions1. Hadrian’s work had some elements in common
with a typical qanat, but it was an aqueduct2. In general:
Although there are some similarities, qanats and aqueducts are quite different water supply systems
Why is this important?There is enough misunderstanding of the
word qanat. Differences Persian qanats and Roman aqueducts