Turpan Karez (Kariz) Irrigation System — Turfan Depression
吐鲁番坎儿井 · Karez · Qanat Turfan · Turpan Water System
Han to Qing (2nd c. BCE – 19th c. CE)·Han Chinese, Turkic Uyghur, Gaochang Tokharian, Hui·🇨🇳 Xinjiang Uyghur Autonomous Region, Turpan Prefecture, China
About
About Turpan Karez (Kariz) Irrigation System — Turfan Depression
5,000-km aggregate qanat network tapping Tianshan snow-melt under the Flaming Mountains to irrigate the Turpan Depression oasis 154 m below sea level — lowest irrigation on earth. 5–35 L/s per karez by gravity alone at 3‰ grade. The depression's 3,200 hours sun and 50-m deep karez reservoirs create a 2,000-year oasis supporting 30,000 ha of grapes (world's largest raisin centre). The Karez Museum shows a live shaft cross-section.
Why it mattersLongest continuously operating qanat system globally merging Persian, Han and Uyghur technology at lowest terrestrial irrigation elevation.
Open questions
Mysteries & theories
Mysteries
- 01Whether Han karez predate Islamic Persian west-to-east diffusion (reverse route)
- 02How 3‰ grade held through shifting alluvial fans without perennial survey
Theories
- 01Silk Road technology transfer via captured Persian craftsmen after Han-Xiongnu war
- 02Oasis urbanism prerequisite for Gaochang city-state
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- Trad. 206 BCE Han (first wave); massive Gaochang 500–640 CE and Qing 17th c.
- Period
- Han to Qing (2nd c. BCE – 19th c. CE)
- Culture
- Han Chinese, Turkic Uyghur, Gaochang Tokharian, Hui
- Builders
- Han frontier engineers and Gaochang Uyghur karez masters (kariz jen)
- Purpose
- Gravity irrigation and oasis urbanism in rainless Turfan Depression (<16 mm/yr) avoiding evaporation by 90% underground
- Abandoned
- 616 karez still active; 1168 dry with water-table fall
- Rediscovered
- 1902 Aurel Stein maps; 1990s Xinjiang Water Ministry census
- Excavation
- Excavation ongoing
138 BCE
Zhang Qian reports Persian qanat to Han Wudi
500 CE
Gaochang excavates 30 km Desert Karez to Gaochang city
1785
Qing renovation after Dzungar war: 1,000 karez recorded
On the ground
Structures & features
42.9400° N · 89.1800° E · -80 m · 3 mapped features
Karez Museum Live Section
museum karezShaft 40 m deep with walkable 30-m tunnel and reservoir
42.9500° N · 89.1900° EMazar Karez Fan-Head
headworksHead shafts under Flaming Mountains at Tianshan toe
42.9700° N · 89.0500° EGaochang Ancient City Karez Feeder
urban karez3-km walled city feeder now dry moat karez channel
42.8556° N · 89.5280° E