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

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: 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 usersLocal 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 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: 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 storageWater storage site Entrance

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

Example:Hadrian’s aqueduct in Athens

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

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

CE) (Saldae, Algeria)

Differences Persian qanats and Roman aqueducts