Abstract
Modification of the hydrological cycle and, subsequently, of other global cycles is expected in Arctic watersheds owing to global change. Future climate scenarios imply widespread permafrost degradation caused by an increase in air temperature, and the expected effect on permafrost hydrology is immense. This study aims at analyzing, and quantifying the daily water transfer in the largest Arctic river system, the Yenisei River in central Siberia, Russia, partially underlain by permafrost. The semi-distributed SWAT (Soil and Water Assessment Tool) hydrological model has been calibrated and validated at a daily time step in historical discharge simulations for the 2003–2014 period. The model parameters have been adjusted to embrace the hydrological features of permafrost. SWAT is shown capable to estimate water fluxes at a daily time step, especially during unfrozen periods, once are considered specific climatic and soils conditions adapted to a permafrost watershed. The model simulates average annual contribution to runoff of 263 millimeters per year (mm yr−1) distributed as 152 mm yr−1 (58%) of surface runoff, 103 mm yr−1 (39%) of lateral flow and 8 mm yr−1 (3%) of return flow from the aquifer. These results are integrated on a reduced basin area downstream from large dams and are closer to observations than previous modeling exercises.
Highlights
Ongoing climate change became consensual through a plethora of studies [1]
We have shown the importance of modeling at a daily time step in Arctic watersheds to collect more information on the hydrological behavior of those basins
The objectives of this paper have been to better analyze water fluxes and pathways in Arctic rivers and produce a performing model adapted to permafrost soils
Summary
Ongoing climate change became consensual through a plethora of studies [1]. This global warming is important at high latitudes because of the Arctic amplification effect [2]. Significant alteration of the hydrological cycle and, subsequently, in other global cycles is expected in Arctic watersheds [3,4,5,6]. Arctic hydrology is poorly understood, and largely understudied, compared to lower and mid–latitudes [7,8]. Arctic catchments are genuinely remote areas, where data acquisition is complicated by natural conditions, logistics and societal issues. Field studies are scarce and these data, for the Russian territory, are virtually unexposed to a wider international audience [9]
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