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| Titel |
Geometric dependency of Tibetan lakes on glacial runoff |
| VerfasserIn |
V. H. Phan, R. C. Lindenbergh, M. Menenti |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-21), S.4061-4077 |
| Datensatznummer |
250085964
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| Publikation (Nr.) |
 copernicus.org/hess-17-4061-2013.pdf |
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| Zusammenfassung |
| The Tibetan Plateau is an essential source of water for Southeast Asia. The
runoff from its ~34 000 glaciers, which occupy an area of
~50 000 km2, feeds Tibetan lakes and major Asian rivers
like the Indus and Brahmaputra. Reported glacial shrinkage likely has an impact
on the runoff. Unfortunately, accurate quantification of glacial changes is
difficult over the high-relief Tibetan Plateau. However, it has recently
been shown that it is possible to directly assess water level changes of a
significant number of the ~900 Tibetan lakes with an area
over 1 km2. This paper exploits different remote sensing products to
create drainage links between Tibetan glaciers, lakes and rivers. The
results allow us to differentiate between lakes with and without outlet. In
addition, we introduce the notion of geometric dependency of a lake on
glacial runoff, defined as the ratio between the total area of glaciers
draining into a lake and the total area of the lake catchment. We determined
these dependencies for all ~900 sufficiently large Tibetan
lakes. To do so, we combined three remote sensing products: the CAREERI
glacier mask product, a lake mask product based on the MODIS MOD44W water
product and the HydroSHEDS river network product derived from Shuttle Radar
Topography Mission (SRTM) elevation data. Using a drainage network analysis,
we determined all drainage links between glaciers and lakes. The results
show that 25.3% of the total glacier area directly drains into one of 244
Tibetan lakes. The results also give the geometric dependency of each lake
on glacial runoff. For example, there are ten lakes with direct glacial
runoff from at least 240 km2 of glacier. Three case studies, including
one of the well-studied Nam Tso Lake, demonstrate how the geometric
dependency of a lake on glacial runoff can be directly linked to
hydrological processes. |
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