Lhasa He

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Lhasa He
Gyi Qu / Kyi Chu
Data
location Tibet ( PR China )
River system Brahmaputra
Drain over Brahmaputra  → Indian Ocean
source in Nyainqêntanglha
Source height 5290  m
muzzle in the Brahmaputra coordinates: 29 ° 20 ′ 27 "  N , 90 ° 45 ′ 38"  E 29 ° 20 ′ 27 "  N , 90 ° 45 ′ 38"  O
Mouth height 3590  m
Height difference 1700 m
Bottom slope 4.3 ‰
length 395 km
Big cities Lhasa
Small towns Lhünzhub
Tibetan name
Tibetan script :
ལྷ་ ས་ གཙང་ པོ ། སྐྱིད་ ཆུ །
Wylie transliteration :
lha sa gtsang po,
skyid chu
Official transcription of the PRCh :
Lhasa Zangbo,
Gyi Qu
THDL transcription :
Lhasa Tsangpo,
Kyichu
Other spellings:
Lhasa River,
Kyi Chu
Chinese name
Traditional :
拉薩 河 、 吉 曲
Simplified :
拉萨 河 、 吉 曲
Pinyin :
Lāsà Hé, Jí Qǔ

The Lhasa He ( Tib .: lha sa gtsang po, Tibetan : ལྷ་ ས་ གཙང་ པོ , Chinese  拉薩 河  /  拉萨 河 , Pinyin Lāsà Hé ), also Gyi Qu or Kyi Chu ( Tib .: skyid chu, Tibetan : སྐྱིད ་ ཆུ ། ), is a northern inlet of the Yarlung Zangbo, the upper reaches of the Brahmaputra in Tibet , and rises in the Nyainqêntanglha Mountains in the Tibetan highlands.

The source of the Lhasa He is located at a strongly melting glacier gate at an altitude of 5290 m in the central Nyainqêntanglha Mountains, around 15 km southwest of the highest peak (7117 m), around 30 km north of Yangpacen , 15 km east of the Guring La pass (5972 m). The source was discovered by the Bremen geologist and glaciologist Dieter Ortlam on August 14, 1989 during geophysical-glaciological investigations.

The Lhasa River is around 395 km long. Significant tributaries are from the north the Damchu (Tib .: 'dam chu , Tibetan: འདམ་ ཆུ ། , Dāng Qǔ 当 曲 ), from the east the Miggi Chu and from the west the Tobing Chu. The Lhasa River flows east of Qüxü at an altitude of 3590 m below the Zangbo Bridge from Lhasa , after Gongkar Airport in the Yarlung Zangbo.

The river runs very winding along the places Lhünzhub (4065 m), Radreng Gömpa, Maizhokunggar (3750 m), Dagzê (3690 m), Lhasa (3650 m) and Qüxü (3590 m). The gradient from the source to the mouth is 1600 m, 1:25 or 4%; in the lower reaches from Maizhokunggar only 1% (with subglacial deepening). The catchment area of ​​the Lhasa River is about 26,000 km².

Through numerous documents - u. a. U-valleys, glacial pot fields and cascades in granite and Jurassic limestone far above the valley floor , from erratic blocks e.g. B. Jurassic limestone on granite west of Lhasa or granite and gneiss on Jurassic limestone on the Ganden summit (= Zhog Riwoqe, approx. 4500 m), from Roches moutonnées with glacier scratches or mirrors and windward / lee side - Moraines in the Gongkar-Lhasa-Yangpacen- Ganden area - a more than 2500 m thick Upper Pleistocene ice sheet can be derived in the valleys of the Lhasa River and the Yarlung Tsangpo. An exact age dating is still open for the time being (probably one of the last two cold ages).

literature

  • R. von Milleville (1987): South Central Tibet Route Map 1: 1 million - Edward Stanford Ltd., London.
  • D. Ortlam (1991): Hammer blow seismic investigations in the high mountains of northern Tibet. - Z. Geomorphologie, NF, 35.4: 385-399, 12 figs., 1 tab., Berlin / Stuttgart.

Footnotes

  1. ↑ Coordinates of the source: 90 ° 28 'E, 30 ° 19' N.
    According to Xīzàng dìmíng 西藏 地名 / bod ljongs sa ming བོད་ ལྗོངས་ ས་ མིང ། ( Tibetan place names ; Beijing, Zhōngguó Zàngxué chūbǎnshè 中国 藏 学 出版社 1995); ISBN 7-80057-284-6 , p. 306 the source of the Lhasa River is in the Lhari district of the Nagqu administrative district , in the moor in the east of the Midika basin ( smi di ka སྨི་ དི་ ཀ ། / Màidìkǎ 麦 地 卡 )