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| Titel |
A water availability and low-flow analysis of the Tagliamento River discharge in Italy under changing climate conditions |
| VerfasserIn |
L. N. Gunawardhana, S. Kazama |
| 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 ; 16, no. 3 ; Nr. 16, no. 3 (2012-03-30), S.1033-1045 |
| Datensatznummer |
250013226
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| Publikation (Nr.) |
 copernicus.org/hess-16-1033-2012.pdf |
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| Zusammenfassung |
| This study estimated the effects of projected variations in precipitation
and temperature on snowfall-snowmelt processes and subsequent river
discharge variations in the Tagliamento River in Italy. A lumped-parameter,
non-linear, rainfall-runoff model with 10 general circulation model (GCM)
scenarios was used. Spatial and temporal changes in snow cover were assessed
using 15 high-quality Landsat images. The 7Q10 low-flow probability
distribution approximated by the Log-Pearson type III distribution function
was used to examine river discharge variations with respect to climate
extremes in the future. On average, the results obtained for 10 scenarios
indicate a consistent warming rate for all time periods, which may increase
the maximum and minimum temperatures by 2.3 °C (0.6–3.7 °C) and 2.7 °C (1.0–4.0 °C), respectively, by the end of the 21st century
compared to the present climate. Consequently, the exponential rate of frost
day decrease for 1 °C winter warming in lower-elevation areas is
approximately three-fold (262%) higher than that in higher-elevation
areas, revealing that snowfall in lower-elevation areas will be more
vulnerable under a changing climate. In spite of the relatively minor
changes in annual precipitation (−17.4 ~ 1.7% compared to the average
of the baseline (1991–2010) period), snowfall will likely decrease by
48–67% during the 2080–2099 time period. The mean river discharges are
projected to decrease in all seasons, except winter. The low-flow analysis
indicated that while the magnitude of the minimum river discharge will
increase (e.g. a 25% increase in the 7Q10 estimations for the winter
season in the 2080–2099 time period), the number of annual average low-flow
events will also increase (e.g. 16 and 15 more days during the spring and
summer seasons, respectively, in the 2080–2099 time period compared to the
average during the baseline period), leading to a future with a highly
variable river discharge. Moreover, a consistent shift in river discharge
timing would eventually cause snowmelt-generated river discharge to occur
approximately 12 days earlier during the 2080–2099 time period compared to
the baseline climate. These results are expected to raise the concern of
policy makers, leading to the development of new water management strategies
in the Tagliamento River basin to cope with changing climate conditions. |
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