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Titel |
Role of glaciers in watershed hydrology: a preliminary study of a "Himalayan catchment" |
VerfasserIn |
R. J. Thayyen, J. T. Gergan |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 4, no. 1 ; Nr. 4, no. 1 (2010-02-09), S.115-128 |
Datensatznummer |
250001549
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Publikation (Nr.) |
copernicus.org/tc-4-115-2010.pdf |
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Zusammenfassung |
A large number of Himalayan glacier catchments are under the influence of
humid climate with snowfall in winter (November–April) and south-west
monsoon in summer (June–September) dominating the regional hydrology. Such
catchments are defined as "Himalayan catchment", where the glacier meltwater
contributes to the river flow during the period of annual high flows
produced by the monsoon. The winter snow dominated Alpine catchments of the
Kashmir and Karakoram region and cold-arid regions of the Ladakh mountain
range are the other major glacio-hydrological regimes identified in the
region. Factors influencing the river flow variations in a "Himalayan
catchment" were studied in a micro-scale glacier catchment in the
Garhwal Himalaya, covering an area of 77.8 km2. Three hydrometric
stations were established at different altitudes along the Din Gad stream
and discharge was monitored during the summer ablation period from 1998 to
2004, with an exception in 2002. These data have been analysed along with
winter/summer precipitation, temperature and mass balance data of the
Dokriani glacier to study the role of glacier and precipitation in
determining runoff variations along the stream continuum from the glacier
snout to 2360 m a.s.l. The study shows that the inter-annual runoff
variation in a "Himalayan catchment" is linked with precipitation rather
than mass balance changes of the glacier. This study also indicates that the
warming induced an initial increase of glacier runoff and subsequent decline
as suggested by the IPCC (2007) is restricted to the glacier
degradation-derived component in a precipitation dominant Himalayan
catchment and cannot be translated as river flow response. The preliminary
assessment suggests that the "Himalayan catchment" could experience higher
river flows and positive glacier mass balance regime together in association
with strong monsoon. The important role of glaciers in this precipitation
dominant system is to augment stream runoff during the years of low summer
discharge. This paper intends to highlight the importance of creating
credible knowledge on the Himalayan cryospheric processes to develop a more
representative global view on river flow response to cryospheric changes and
locally sustainable water resources management strategies. |
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