View source for Turpan Depression

{{Short description|Fault-bounded trough in the Tian Shan mountain range}}
{{coord|42.78|N|89.34|E|display=title}}
{{Chinese
|title=Turpan Depression
|pic=Turpan Depression, nestled at the foot of China’s Bogda Mountains.jpg
|picsize=250px
|piccap=The Turpan Depression, nestled at the foot of China's [[Bogda Shan|Bogda Shan Mountains]].
|s=吐鲁番盆地
|t=吐魯番盆地
|p=Tǔlǔfán Péndì
|uig=تۇرپان ئويمانلىقى|uly=''Turpan Oymanliqi''|usy=Турпан Ойманлиқи
}}

The '''Turpan Depression''' or '''Turfan Depression''', is a [[fault (geology)|fault]]-bounded trough located around and south of the city-[[oasis]] of [[Turpan]], in the [[Xinjiang|Xinjiang Autonomous Region]] in far [[Western China]], about {{convert|150|km}} southeast of the regional capital [[Ürümqi]]. It includes [[Lake Ayding]], {{convert|−154|m|0}}, the [[List of places on land with elevations below sea level|second or third lowest]] [[Depression (geology)|depression]] on [[Earth]].<ref>
After the [[Jordan valley]] (−430 m) and equal to the [[Afar Depression]] within the accuracy of reported measurements (−155 m to −153 m).
{{cite web
|url=http://www.nasa.gov/multimedia/imagegallery/image_feature_533.html
|title=NASA - Bogda Mountains
|publisher=www.nasa.gov
|access-date=2009-10-09
}}</ref> 
By some measures, it is also the hottest and driest area in China during the summer.<ref>{{cite news|url=http://www.shanghaidaily.com/sp/article/2010/201004/20100405/article_433203.htm|publisher=Shanghai Daily|title=If you can stand the heat, then the Turpan Basin is the place to be|date=April 5, 2010|url-status=dead|archive-url=https://web.archive.org/web/20100407094332/http://www.shanghaidaily.com/sp/article/2010/201004/20100405/article_433203.htm|archive-date=April 7, 2010}}</ref>

==Geology and relief==
The Turpan Basin is a fault-bounded trough located in the eastern part of the [[Tian Shan]]. It covers an area of {{convert|50000|km2}}. The surrounding mountain ranges are: the central Tian Shan in the west, the [[Bogda Shan]] in the north-west, the Haerlike Shan in the north-west, and the Jueluotage Shan in the south. Beyond the surrounding mountain ranges lie the [[Dzungaria|Junggar Basin]] in the north and the [[Tarim Basin]] in the south.

Some geographers also use the term Turpan-Hami Basin, which is understood as including the Turpan Depression along with the [[Hami Depression]] (located to the east of the Turpan Depression, and to the southwest of the city of [[Hami City|Hami]]) and the Liaodong Uplift separating the two depressions. A source using this terminology gave the area of the Turpan Depression proper as {{convert|28600|km2|abbr=on}}, that of the Hami Depression as {{convert|19300|km2|abbr=on}}, and for the entire Turpan-Hami Basin, as {{convert|48000|km2|abbr=on}}.<ref name=uranium>{{citation
|first=Franz J.|last=Dahlkamp |isbn=978-3-540-78557-6 |title=Uranium Deposits of the World: Asia |publisher= Springer
|url= https://books.google.com/books?id=ShzwRGs5mDYC&pg=PA40 |pages=40–41 |date=2009-09-16 }}</ref>

[[Image:Turpan-flaming-mountains-camellos-d01.jpg|thumb|250px|Basin scene near [[Flaming Mountains]]]]

The Turpan Basin formed in a [[shear zone]] during the [[Lopingian|Late Permian]] due to motion between the [[East European craton|East European]] and the [[Angaran craton]]. It was subsequently deformed by the collision of the [[Indian Plate]] and [[Eurasian Plate]] in the [[Cenozoic]]. In the latter deformation, a thrust fault belt running from east to west, the [[Flaming Mountains]], was formed in the center of the basin. The Flaming Mountains are {{convert|98|km|abbr=on}} long and {{convert|9|km|abbr=on}} wide; the highest peak reaches an elevation of {{convert|831.7|m|abbr=on}} above sea level. The Turfan volcano is located near Turpan.

Also in the center of the basin lies the [[Ayding Lake]] (Moonlight Lake) which has an elevation of {{convert|154.5|m|abbr=on}} below sea level, the [[List of elevation extremes by country|sixth lowest exposed elevation on the Earth's land surface]]. It is the lowest surface point in China.

The Shihongtan [[uranium]] ore deposit is located at the southwestern margin of the Turpan Depression, some {{convert|35|km|abbr=on}} south-southwest from Turpan City.<ref name=uranium/>

==History of human settlement==
[[Image:Turpan-gaochang-d12.jpg|thumb|250px|Ruins of Gaochang]]
The ancient city of [[Gaochang]] was a key point on the ancient [[Silk Road]] and dates back to the 1st century BC. It was burnt down in wars in the 14th century. The [[Bezeklik Thousand Buddha Caves]], which are located in the [[Flaming Mountains]]' [[Mutou Valley]], about {{convert|30|km|abbr=on}} east of the city of Turpan, have been hewn into the rock from the [[Tang dynasty]]–era up to the time of the [[Yuan dynasty]] (13th century). The caves are famous for their murals, which can still be found in about 40 of the 77 known caves. The desert climate has favored preservation of the content of the [[Astana Cemetery|Astana-Karakhoja ancient tombs]], which are located about 6&nbsp;km from the ancient city of Gaochang. The tombs are the burial place for nobles, officials, and others who were interred there from the times of the [[Jin dynasty (265–420)|Western Jin dynasty]] until the middle of the Tang dynasty era.

The modern city of [[Turpan]] has a population of 242,000, of whom 71% are [[Uyghurs|Uyghur]].<ref name=xinjiang/> For water, the city relies on wells and traditional ''[[karez]]'' (meaning "well" in the local [[Uyghur language]]).<ref name=xinjiang>{{cite book|editor=S. Frederick Starr|title=Xinjiang: China's Muslim Borderland: China's Muslim Borderland|page=266|publisher=[[Routledge]]}}</ref>

==Climate==
The Turpan Basin has a harsh, continental [[desert climate]] (Koppen ''BWk'') in which the precipitation is far less than the potential evaporation. At Turpan City, July is the hottest month with a 24-hour average temperature of {{convert|32.2|C|1}} and January the coldest with a 24-hour average temperature of {{convert|−7.6|C|1}}. Monthly rainfall is highest in June, at {{convert|2.9|mm}} and lowest in February and April, at {{convert|0.5|mm|abbr=on}}. The annual average precipitation is only {{convert|15.7|mm|abbr=on}}, falling on only 13 days per year. In contrast to this, the potential annual evaporation rate reaches {{convert|3000|mm|abbr=on}}.{{citation needed|date=February 2013}} Because of its climate, the area is sometimes counted as one of the ''Furnaces of China'', although the locations included under this heading vary.

{{Turpan weatherbox}}

==Vegetation and agriculture==
[[File:Txu-oclc-6654394-nk-45-3rd-ed.jpg|left|thumb|Map including the Turfan Depression (labeled as T'U-LU-FAN P'EN-TI) (1975)]]
[[Image:Turpan-calles-d01.jpg|thumb|250px|Qingnian Lu, a [[Turpan]] city street shaded by grapevine [[Trellis (architecture)|trellises]] in China's [[Grape Valley]]]]
On the shores of [[Ayding Lake|Aydingkol Lake]], reeds, [[tamarix|tamarisks]], [[Haloxylon|saxauls]], as well as other shrubs and weeds can be found. Away from sources of water, the Turpan Basin is not covered by vegetation. Consequently, agriculture is limited to oasis and depends on a sophisticated irrigation system known as the ''[[Turpan water system|Karez System]]''. The irrigation water comes from the surrounding mountain ranges, in particular from the annual melting of the snow. The Karez System consists of wells, underground channels, ground canals, and small reservoirs, which use the natural slope of the terrain to sustain the water flow and guide the water right to the plants while minimizing evaporation all along the way. The historical record of the system extends back to the [[Han dynasty]]. The number of Karez systems in the area is slightly below one thousand and the total length of the canals is about {{convert|5000|km|abbr=on}} in length. The Karez System is therefore considered one of the three great ancient projects in China along with the [[Great Wall of China|Great Wall]] and the [[Grand Canal (China)|Grand Canal]]. Recently, development of groundwater through tubewells has led to a general fall in water tables, and many karez systems have failed. Farming in the Turpan Basin is particularly famous for its fruit. Because of the dry and hot conditions, the fruits grown in the depression have very high concentrations of sugar. They are traditionally processed by drying in open drying barns. The cultivated fruit include: [[Morus (plant)|mulberry]], [[peach]], [[apricot]], [[apple]], [[pomegranate]], [[pear]], [[ficus|fig]], [[walnut]], as well as [[grape]]s, [[watermelon]]s and [[true melon]]s. Among the fruit, the grapes stand out: more than 100 varieties of grape are cultivated in the area and it accounts for 90% of China's seedless grape crop. Other specialty agricultural products of the region are Donghu [[Hami melon]]s and [[Gossypium hirsutum|long-staple cotton]].

==Sources==
* {{cite journal |last1= Lei |first1= Shao |first2= Karl |last2= Statteggerb |last3= Wenhou |first3= Lic |first4= Bernd J. |last4= Haupt |date= 1999 |title= Depositional style and subsidence history of the Turpan Basin (NW China) |journal= Sedimentary Geology |volume= 128 |issue= 1–2 |pages= 155–169 |doi= 10.1016/S0037-0738(99)00066-4 |bibcode= 1999SedG..128..155S }}
* {{cite journal |last1= Allen |first1= M.B. |last2= Sengör |first2= A.M.C. |last3= Natal'in |first3= B.A. |date= 1995 |title= Junggar, Turpan and Alakol basins as Late Permian to Early Triassic extensional structures in a sinistral shear zone in the Altaid orogenic collage, Central Asia |journal= Journal of the Geological Society |volume= 152 |issue= 2 |pages= 327–338 |doi= 10.1144/gsjgs.152.2.0327 |url= http://jgs.geoscienceworld.org/content/152/2/327 |bibcode= 1995JGSoc.152..327A |s2cid= 128482060 |url-access= subscription }}

==Notes==
{{Reflist}}

==External links==
* [http://www.worldclimate.com Climate data]

{{Xinjiang topics}}
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[[Category:Turpan]]
[[Category:Landforms of China]]
[[Category:Depressions (geology)]]
[[Category:Landforms of Xinjiang]]