Turfan water system
Encyclopedia
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, is a qanat
Qanat
A qanāt is a water management system used to provide a reliable supply of water for human settlements and irrigation in hot, arid and semi-arid climates...
system adapted by the Turpan people. The Chinese claim the karez system as one of the three greatest water projects of China, linking it with the Dujiangyan Irrigation System
Dujiangyan Irrigation System
Dujiangyan is an irrigation infrastructure built in 256 BC during the Warring States Period of China by the Kingdom of Qin. It is located in the Min River in Sichuan province, China, near the capital Chengdu. It is still in use today to irrigate over 5,300 square kilometers of land in the region...
and the Grand Canal. The karezes are a Persian invention
The word karez means "well" in the local Uyghur language
Uyghur language
Uyghur , formerly known as Eastern Turk, is a Turkic language with 8 to 11 million speakers, spoken primarily by the Uyghur people in the Xinjiang Uyghur Autonomous Region of Western China. Significant communities of Uyghur-speakers are located in Kazakhstan and Uzbekistan, and various other...
. Turpan has the Turpan Water Museum (a Protected Area of the People's Republic of China) dedicated to demonstrating its karez water system, as well as exhibiting other historical artifacts.
Turpan's well system was crucial in Turpan's development as an important oasis stopover
Oasis
In geography, an oasis or cienega is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source...
on the ancient Silk Road
Silk Road
The Silk Road or Silk Route refers to a historical network of interlinking trade routes across the Afro-Eurasian landmass that connected East, South, and Western Asia with the Mediterranean and European world, as well as parts of North and East Africa...
skirting the barren and hostile Taklamakan Desert. Turpan owes its prosperity to the water provided by its karez well system.
Description
Horizontal plane
In geometry, physics, astronomy, geography, and related sciences, a plane is said to be horizontal at a given point if it is perpendicular to the gradient of the gravity field at that point— in other words, if apparent gravity makes a plumb bob hang perpendicular to the plane at that point.In...
series of vertically dug well
Water well
A water well is an excavation or structure created in the ground by digging, driving, boring or drilling to access groundwater in underground aquifers. The well water is drawn by an electric submersible pump, a trash pump, a vertical turbine pump, a handpump or a mechanical pump...
s that are then linked by underground water canal
Canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...
s to collect water from the watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
surface runoff
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
from the base of the Tian Shan Mountains
Tian Shan
The Tian Shan , also spelled Tien Shan, is a large mountain system located in Central Asia. The highest peak in the Tian Shan is Victory Peak , ....
and the nearby Flaming Mountains
Flaming Mountains
The Flaming Mountains or Gaochang Mountains are barren, eroded, red sandstone hills in Tian Shan Mountain range, Xinjiang, China. They lie near the northern rim of the Taklamakan Desert and east of the city of Turpan...
. The canals channel the water to the surface, taking advantage of the current provided by the gravity of the downward slope of the Turpan Depression. The canals are mostly underground to reduce water evaporation
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....
.
The system has wells, dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s and underground canals built to store the water and control the amount of water flow. Vertical wells are dug at various points to tap into the groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
flowing down sloping land from the source, the mountain runoff
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
. The water is then channeled through underground canals dug from the bottom of one well to the next well and then to the desired destination, Turpan's irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
system. This irrigation system of special connected wells originated during the Han Dynasty
Han Dynasty
The Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...
(206 BCE – 24 CE).
In Xinjiang
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...
, the greatest number of karez wells are in the Turpan Depression, where today there remain over 1100 karez wells and channels having a total length of over 5000 kilometres (3,106.9 mi). The local geography makes karez wells practical for agricultural irrigation and other uses. Turpan is located in the second deepest geographical depression
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
in the world, with over 4000 km² (1,544.4 sq mi) of land below sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
and with soil that forms a sturdy basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
. Water naturally flows down from the nearby mountains during the rainy season in an underground current to the low depression basin under the desert. The Turpan summer is very hot and dry with periods of wind and blowing sand. The water from the underground channels provides a stable water source year round, independent of season.
Importance
Camel train
A camel train is a series of camels carrying goods or passengers in a group as part of a regular or semi-regular service between two points. Although they rarely travelled faster than the walking speed of a man, camels' ability to handle harsh conditions made camel trains a vital part of...
on the Silk Route resting there near a route skirting the Taklamakan Desert. The caravans included merchant trader
Merchant
A merchant is a businessperson who trades in commodities that were produced by others, in order to earn a profit.Merchants can be one of two types:# A wholesale merchant operates in the chain between producer and retail merchant...
s and missionaries
Missionary
A missionary is a member of a religious group sent into an area to do evangelism or ministries of service, such as education, literacy, social justice, health care and economic development. The word "mission" originates from 1598 when the Jesuits sent members abroad, derived from the Latin...
with their armed escorts, animals including camels, sometimes numbering into the thousands, along with camel drivers, agents and other personnel, all of whom might stay for a week or more. The caravans needed pastures for their animals, resting facilities, trading bazaar
Bazaar
A bazaar , Cypriot Greek: pantopoula) is a permanent merchandising area, marketplace, or street of shops where goods and services are exchanged or sold. The term is sometimes also used to refer to the "network of merchants, bankers and craftsmen" who work that area...
s for conducting business, and replenishment of food and water.
