 |
| Titel |
Climatic and geologic controls on suspended sediment flux in the Sutlej River Valley, western Himalaya |
| VerfasserIn |
H. Wulf, B. Bookhagen, D. Scherler |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 7 ; Nr. 16, no. 7 (2012-07-20), S.2193-2217 |
| Datensatznummer |
250013374
|
| Publikation (Nr.) |
 copernicus.org/hess-16-2193-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| The sediment flux through Himalayan rivers directly impacts water quality and
is important for sustaining agriculture as well as maintaining drinking-water
and hydropower generation. Despite the recent increase in demand for these
resources, little is known about the triggers and sources of extreme sediment
flux events, which lower water quality and account for extensive hydropower
reservoir filling and turbine abrasion. Here, we present a comprehensive
analysis of the spatiotemporal trends in suspended sediment flux based on
daily data during the past decade (2001–2009) from four sites along the
Sutlej River and from four of its main tributaries. In conjunction with
satellite data depicting rainfall and snow cover, air temperature and
earthquake records, and field observations, we infer climatic and geologic
controls of peak suspended sediment concentration (SSC) events. Our study
identifies three key findings: First, peak SSC events (≥ 99th SSC
percentile) coincide frequently (57–80%) with heavy rainstorms and
account for about 30% of the suspended sediment flux in the semi-arid to
arid interior of the orogen. Second, we observe an increase of suspended
sediment flux from the Tibetan Plateau to the Himalayan Front at mean annual
timescales. This sediment-flux gradient suggests that averaged, modern
erosion in the western Himalaya is most pronounced at frontal regions, which
are characterized by high monsoonal rainfall and thick soil cover. Third, in
seven of eight catchments, we find an anticlockwise hysteresis loop of annual
sediment flux variations with respect to river discharge, which appears to be
related to enhanced glacial sediment evacuation during late summer. Our
analysis emphasizes the importance of unconsolidated sediments in the
high-elevation sector that can easily be mobilized by hydrometeorological
events and higher glacial-meltwater contributions. In future climate change
scenarios, including continuous glacial retreat and more frequent monsoonal
rainstorms across the Himalaya, we expect an increase in peak SSC events,
which will decrease the water quality and impact hydropower generation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|