Using Modeling Tools to Better Understand Permafrost Hydrology

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.

A Guideline for Successful Calibration and Uncertainty Analysis for Soil and Water Assessment: A Review of Papers from the 2016 International SWAT Conference

“…6-Fabre et al [30] studied the effect of permafrost degradation as a result of increasing temperature in the largest Arctic river system: the Yenisei River in central Siberia, Russia. Once the climate data and soil conditions were adapted to a permafrost watershed, the calibration results showed SWAT was able to estimate water fluxes at a daily time step, especially during unfrozen periods.…”

Assessment of sediment and organic carbon exports into the Arctic ocean: The case of the Yenisei River basin

“…Importantly, both the SWAT model and the ArcSWAT interface are openesource and free, allowing reproducibility of the results once the input data are welledocumented (Olivera et al, 2006). The SWAT model has already been tested in Arctic systems (Krysanova and White, 2015;Hülsmann et al, 2015) and revealed its capability to accurately represent permafrost hydrology (Fabre et al, 2017). Theory and details of hydrological processes inte grated in SWAT model are available online in the SWAT docu mentation (http://swatmodel.tamu.edu/).…”

“…Numerous models have been used in past researches to simulate permafrost hydrology. (Fabre et al, 2017). The TOPMODEL, a surface runoff model, has shown its limits for small to the largest Arctic watersheds by omitting lateral and groundwater flow (Stieglitz et al, 2003;Finney et al, 2012).…”

“…The Soil and Water Assessment Tool (SWAT) has allowed us to cross all the obstacles revealed by the previous modeling efforts. Its capability to simulate water and sediment fluxes at a daily time step (Douglas Mankin et al, 2010;Krysanova and White, 2015) is an important advantage to detect the freshets in Arctic systems (Fabre et al, 2017) and it has already shown its potential to study daily organic carbon exports (Oeurng et al, 2011).…”

Permafrost Hydrology Research Domain: Process-Based Adjustment

“…Hydrological modelling strategies accounting for permafrost-specific processes should be developed or further enhanced for their better representation. The most promising approaches include: (1) Coupled water and heat balance models of various dimension and complexity, e.g., the 'zero-dimensional' model of Boike et al [22], PFLOTRAN [96], SUTRA 3.0 (aka SUTRA-ice) [97] and permaFOAM [98], to mention but a few; (2) an explicit two-dimensional heat transfer model with phase transitions, where water and heat fluxes are decoupled [99]; and (3) semi-distributed models with a simplistic permafrost description as an impermeable layer, and no heat transfer module [100,101].…”