Abstract

The Arctic is warming rapidly. Changing seasonal freezing and thawing cycles of the soil are expected to affect river run-off substantially, but how soil frost influences river run-off at catchment scales is still largely unknown. We hypothesize that soil frost alters flow paths and therefore affects storage-discharge relations in subarctic catchments. To test this hypothesis, we used an approach that combines meteorological records and recession analysis. We studied streamflow data (1986-2015) of Abiskojokka, a river that drains a mountainous catchment (560 km(2)) in the north of Sweden (68 degrees latitude). Recessions were separated into frost periods (spring) and nofrost periods (summer) and then compared. We observed a significant difference between recessions of the two periods: During spring, discharge was linearly related to storage, whereas storage-discharge relationships in summer were less linear. An analysis of explanatory factors showed that after winters with cold soil temperatures and low snowpack, storage-discharge relations approached linearity. On the other hand, relatively warm winter soil conditions resulted in storage-discharge relationships that were less linear. Even in summer, relatively cold antecedent winter soils and low snowpack levels had a propagating effect on streamflow. This could be an indication that soil frost controls recharge of deep groundwater flow paths, which affects storage-discharge relationships in summer. We interpret these findings as evidence for soil frost to have an important control over river run-off dynamics. To our knowledge, this is the first study showing significant catchment-integrated effects of soil frost on this spatiotemporal scale.

Keywords

Arctic; hydrology; permafrost; recession analysis; snowmelt; soil frost; thawing; warming

Published in

Hydrological Processes
2019, Volume: 33, number: 9, pages: 1304-1316

SLU Authors

• Ploum, Stefan W

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Laudon, Hjalmar

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Oceanography, Hydrology, Water Resources


Publication identifier

DOI: https://doi.org/10.1002/hyp.13401

Permanent link to this page (URI)

https://res.slu.se/id/publ/100459