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Research article - Peer-reviewed, 2023

Modelling Subarctic watershed dissolved organic carbon response to hydroclimatic regime

Sharma, S.; Futter, M. N.; Spence, C.; Venkiteswaran, J. J.; Whitfield, C. J.

Abstract

Shifts in hydroclimatic regimes associated with global climate change may impact freshwater availability and quality. In high latitudes of the northern hemisphere, where vast quantities of carbon are stored terrestrially, explaining landscape-scale carbon (C) budgets and associated pollutant transfer is necessary for understanding the impact of changing hydroclimatic regimes. We used a dynamic modelling approach to simulate streamflow, DOC concentration, and DOC export in a northern Canadian catchment that has undergone notable climate warming, and will continue to for the remainder of this century. The Integrated Catchment model for Carbon (INCA-C) was successfully calibrated to a multi-year period (2012-2016) that represents a range in hydrologic conditions. The model was subsequently run over 30-year periods representing baseline and two future climate scenarios. Average discharge is predicted to decrease under an elevated temperature scenario (22-27 % of baseline) but increase (116-175 % of baseline) under an elevated temperature and precipitation scenario. In the latter scenario the nival hydroclimatic regime is expected to shift to a com-bined nival and pluvial regime. Average DOC flux over 30 years is predicted to decrease (24-27 % of baseline) under the elevated temperature scenario, as higher DOC concentrations are offset by lower runoff. Under the elevated temperature and precipitation scenario, results suggest an increase in carbon export of 64-81 % above baseline. These increases are attributed to greater connectivity of the catchment. The largest increase in DOC export is expected to occur in early winter. These predicted changes in DOC export, particularly under a climate that is warmer and wetter could be part of larger eco-system change and warrant additional monitoring efforts in the region.

Keywords

Catchment; Climate change; Dissolved organic matter; Dynamic modelling; Hydroclimate

Published in

Science of the Total Environment
2023, Volume: 857, article number: 159382
Publisher: ELSEVIER

    Sustainable Development Goals

    SDG13 Climate action

    UKÄ Subject classification

    Climate Research
    Environmental Sciences
    Oceanography, Hydrology, Water Resources

    Publication identifier

    DOI: https://doi.org/10.1016/j.scitotenv.2022.159382

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/120964