 |
| Titel |
Contribution of snow and glacier melt to discharge for highly glacierised catchments in Norway |
| VerfasserIn |
M. Engelhardt, T. V. Schuler, L. M. Andreassen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 18, no. 2 ; Nr. 18, no. 2 (2014-02-10), S.511-523 |
| Datensatznummer |
250120274
|
| Publikation (Nr.) |
 copernicus.org/hess-18-511-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Glacierised catchments show a discharge regime that is strongly influenced by
snow and glacier meltwaters. In this study, we modelled the mass balance and
discharge rates for three highly glacierised catchments (>50% glacier
cover) in western Norway over the period 1961–2012. The spatial pattern of
the catchments follows a gradient in climate continentality from west to
east. The model input were gridded temperature and precipitation values from
seNorge (http://senorge.no) which are available at daily
resolution. The model accounted for accumulation of snow, transformation of
snow to firn and ice, evaporation and melt. Calibration and validation were
performed for each catchment based on measurements of seasonal glacier mass
balances and daily discharge rates, as additional validation data served
daily melt rates from sonic rangers located in the ablation zones of two of
the glaciers. The discharge sources snowmelt, glacier melt and rain were
analysed with respect to spatial variations and temporal evolution. Model
simulations reveal an increase in the relative contribution from glacier melt
to total discharge for the three catchments from less than 10% in the
early 1990s to 15–30% in the late 2000s. The decline in precipitation by
10–20% in the same period was therefore overcompensated, resulting in an
increase in annual discharge by 5–20%. Annual discharge sums and annual
glacier melt are most strongly correlated with annual and winter
precipitation at the most maritime glacier and, with increased climate
continentality, variations in both glacier melt contribution and annual
discharge are becoming more strongly correlated with variations in summer
temperatures. Therefore, glaciers in more continental climates are
especially vulnerable to decrease in
both annual and summer discharge with continued rise in summer temperatures
and subsequent decrease in glacier extent. This may lead to significant
changes to the discharge regime, with increase during spring but decline
later in the year, especially for catchments in less maritime climate
conditions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|