Transcript 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
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: Technology
Element
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: Societal
Element
Persian qanat
Roman aqueduct
3a.
Users
Farmers and general public. By
exception in private housing for cooling
General public use and bathhouses. 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
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
Ownership Cooperation
-
City council
Status
-
Additionally to existing
wells and springs
The only source of
water
Remarks
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