Historical gardens · Horticulture · Sustainability

Water history in gardens – Qanats

The origin of word “qanat” comes from a Semitic word meaning “to dig”.

In ancient times, still a few thousand years ago, Persian started to build underground constructions of channels which allowed to transport water for long distances.

These constructions consisted of underground channels sloped gently down from mountains regions, from where the water was supported from aquifers. Along this channel, at intervals of 20-30 meters the vertical shafts were built to allow to remove the excavated material during construction and maintenance works as well as to provide proper ventilation. The outlets of such qanats were near villages, where the water was distributed to fields in open channels.

KW_qanat

If the underground channels passed through the loose soil, an additional reinforcing was required by the use of special rings.

The water in qanats was transported by use of gravity forces only, therefore there was no need for extra energy consumption and work. And by putting these channels underground, it allowed to reduce the water loss by evaporation.

The water flow in qanat is continuous and therefore there was a need for additional construction for storage of temporary excess of water (in form of cistern, reservoirs, etc).

According to historical records, first qanats were built in ancient Persia then followed by other countries and regions like Mesopotamia, Egypt, Afghanistan, Pakistan, Chinese oasis settlements of Turkistan, Iraq, Syria, Arabia and Yemen, than in Jordan, Syria, Mediterranean region (in ancient Rome – qanat-aqueduct system) as well as in other European countries. The spread of the implementation of qanats techniques were speeded up in the period of early Arab invasions, e.g. in North Africa, Spain and Sicily.

The constructions of qanats type were also discovered in New World, in Mexico, Peru and Chile.

In hot climate, the qanats could be used not only for water transportation but also for cooling. The passive cooling technique was used by the implementation of wind towers.

KW_wind tower and qanat

Some qanats used previously were abandoned due to the introduction of modern irrigation techniques (e.g. mechanically pumped wells), but some of them were abandoned only because of the water tables fall and drying up. But some qanats systems are still in the use at present time e.g. in parts of China, Afghanistan, Pakistan, Iran, Iraq, Oman, Saudi Arabia, Syria, Egypt, Algeria, and Morocco.

.

Some of historical qanats systems are enrolled on the UNESCO World Heritage List, for example:

  • Aflaj Irrigation Systems of Oman (Dakhiliya, Sharqiya and Batinah Regions) – the collection of Aflaj irrigation systems represents some 3,000 still functioning systems in Oman.
  • Al Ain, United Arab Emirates (Hafit, Hili, Bidaa Bint Saud and Oases Areas) – the presence of aflaj systems dating from the Iron Age has been authenticated, but they also include new additions to the system throughout later centuries.
  • Bahla, Oasis of Bahla, 25 km west of Nazwa, Oman.
  • Bam, Kerman Province, Iran – the existence of life in the oasis was based on the underground irrigation canals, of which Bam has preserved some of the earliest evidence in Iran.
  • Persian Qanats, Iran: Qasabeh Gonabad, Qanat of Baladeh, Qanat of Zarch, Hasam Abad-e Moshir Qanat, Ebrahim Abad Qanat, Qanat of Vazvan, Mozd Abad Qanat, Qanat of the Moon, Qanat of Gowhariz, Ghasem Abad, Akbar Abad
  • Serra de Tramuntana, Spain.

.

Qanat’s name in various countries:

  • falaj in Emirates and Oman,
  • foggara in the Sahara regions
  • karez in China  (oasis at Turpan, in northwestern China)
  • khettara in Morocco
  • qarez/ kārīz in Persian
  • Kahn in Balochistan (Iran)
  • acequia in Spanish
  • qanat in Iran and Turkish
  • kahriz/kəhriz  in Azerbaijan
  • kakuriz, chin-avulz or mayun are alternative names used in Asia and North Africa.

.

References:

  1. Hu W.J.,Zhang J.B., Liu Y.Q., 2012, The qanats of Xinjiang: historical development, characteristics and modern implications for environmental protection. Journal of Arid Land, 4(2): 211−220, doi: 10.3724/SP.J.1227.2012.00211
  2. http://whc.unesco.org
  3. Majdecki L., 2016. History of gardens
  4. Wengel T., 1987. The art of gardening through the ages.
  5. Wulff H.E., 1968, The Qanats of Iran, Scientific American, 94-105

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s