Isotopic investigation of runoff generation in a glacierized catchment in northern Sweden
2014 (English)In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 28, no 3, 1383-1398 p.Article in journal (Refereed) Published
In this study, summer rainfall contributions to streamflow were quantified in the sub-arctic, 30% glacierized Tarfala (21.7km(2)) catchment in northern Sweden for two non-consecutive summer sampling seasons (2004 and 2011). We used two-component hydrograph separation along with isotope ratios (O-18 and D) of rainwater and daily streamwater samplings to estimate relative fraction and uncertainties (because of laboratory instrumentation, temporal variability and spatial gradients) of source water contributions. We hypothesized that the glacier influence on how rainfall becomes runoff is temporally variable and largely dependent on a combination of the timing of decreasing snow cover on glaciers and the relative moisture storage condition within the catchment. The results indicate that the majority of storm runoff was dominated by pre-event water. However, the average event water contribution during storm events differed slightly between both years with 11% reached in 2004 and 22% in 2011. Event water contributions to runoff generally increased over 2011 the sampling season in both the main stream of Tarfala catchment and in the two pro-glacial streams that drain Storglaciaren (the largest glacier in Tarfala catchment covering 2.9km(2)). We credit both the inter-annual and intra-annual differences in event water contributions to large rainfall events late in the summer melt season, low glacier snow cover and elevated soil moisture due to large antecedent precipitation. Together amplification of these two mechanisms under a warming climate might influence the timing and magnitude of floods, the sediment budget and nutrient cycling in glacierized catchments.
Place, publisher, year, edition, pages
2014. Vol. 28, no 3, 1383-1398 p.
isotopic hydrograph separation, glacierized catchments, event water contribution, uncertainty estimation
Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:su:diva-100651DOI: 10.1002/hyp.9668ISI: 000329352400078OAI: oai:DiVA.org:su-100651DiVA: diva2:696334
Swedish Society of Anthropology and Geography; Ax:son Johnsons foundation 2014-02-132014-02-102014-02-13Bibliographically approved