1. Streamflow Simulations of the Terrestrial Arctic Regime
Fengge Su, Jennifer C. Adam,
Laura C. Bowling and Dennis P. Lettenmaier
Department of Civil and Environmental Engineering
University of Washington, Seattle, WA
2018/11/9

2. Outline Background Model description Data sources
Streamflow simulations
Conclusion and discussion
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3. Background The importance of freshwater inflow to the ocean systems .
The unique features of arctic land-surface hydrology.
The potential effects of climate change on the runoff of northern rivers.
The need of appropriate hydrologic models for runoff prediction from Pan-Arctic terrestrial domain.
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4. Model description Model features:
multiple vegetation classes in each cell;
energy and water budget closure at each time step;
subgrid infiltration and runoff variability;
and non-linear baseflow generation.
The VIC (Liang et al, 1994;1996) model is a grid-based land surface scheme designed both for inclusion in GCMs, and for use as a stand-alone macro-scale hydrological model.
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5. Cold land processes in VIC
A two-layer energy balance snow model
(Storck et al, 1999)
A frozen soil/permafrost algorithm (Cherkauer et al, 1999; 2003, JGR)
A lakes and wetlands model
(Bowling et al, 2003,WRR)
A blowing snow model
(Bowling et al, 2003, in review)
All of these have been tested at points or catchments scale, but not
ever been applied over the entire Pan-Arctic domain .
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6. Daily time series (1979-1999) of precipitation, maximum
Data sources
Meteorological forcings
Daily time series ( ) of precipitation, maximum
temperature, minimum temperature, wind speed
Land surface characteristics
Soil parameters: from the FAO global soil map.
Land cover characterization: based on University of
Maryland 1-km global vegetation classifications.
Observed data
Discharge data : R-ActicNet V 3.0 (Lammers et al, 2001)
Snow cover extent: NOAA Northern Hemisphere
EASE-Grid Weekly Snow Cover and Sea Ice Extent
Version 2
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7. Streamflow simulations
Study area: Whole Pan-Arctic
Model version: VIC4.1.0 (Release data: 7/31/2003)
Model options: with full energy balance, frozen soil, lake model, and blowing snow
Model resolution: 100 km
Time step: 3-hour
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8. Pan-Arctic Drainage Basins / mask file
Yukon
Lena
Lena
Mackenzie
Yenisei Ob
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9. Arctic river network over 100km grid system
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10. Calibration
The most sensitive soil parameters in the model were infiltration capacity curve (bi), and upper and lower soil depths (d1, d2).
Calibration was performed manually and focused on matching the shape of the monthly hydrograph, and also based on the hydro-climatology of different basins, including surface air temperature, land cover, permafrost extent and runoff ratio.
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11. Infiltration parameter bi
Model Soil Parameters
Lena
Yenesei
Yukon Ob
Mackenzie
Infiltration parameter bi
0.5
0.05~0.1
0.1
Top layer depth (m)
0.1~0.5
Lower layer depth (m)
0.1 ~ 0.3
0.2 ~0.3
0.2~0.25
2.0~2.5
1.0~2.0
Bottom layer depth (m)
0.2 ~ 0.3
0.2~0.3 1
Basin
Soil parameter
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12. Lena Observed Simulated
Aldan at Verhoyanski Perevoz (Area: km2)
Mean monthly hydrograph ( )
Lena at Kusur (Area: km2)
Lena at Kusur
Observed
Simulated
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13. Yenisei Observed Simulated
Nizhnyaya Tunguska at Bol’shoy Porog, Yenisei (Area: km2)
Mean monthly hydrograph ( )
Yenisei at Igarka (Area: km2)
Mean monthly hydrograph ( )
Observed
Simulated
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14. Ob Observed Simulated Mean monthly hydrograph (1979-1994)
Ob at Prokhorkino (Area: km2)
Ob at Salekhard (Area: km2)
Mean monthly hydrograph ( )
Observed
Simulated
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15. Mackenzie Yukon Observed Simulated
Mackenzie at Arctic Red River (Area: km2)
Mean monthly hydrograph ( )
Yukon
Yukon R NR Stevens Village AK (Area: km2)
Yukon R NR Stevens Village AK
Observed
Simulated
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16. Indigirka Yana Observed Simulated
Indigirka at Vorontsovo, Lena (Area: km2)
Yana
Yana at Ubileinaya, Lena (Area: km2)
Observed
Simulated
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17. Mean number of days with snow
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18. Fraction of area covered by snow
Lena Ob
Observed
Simulated
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19. Mean monthly fraction of area covered by snow
Lena
Lena
Mackenzie
Mackenzie Ob Ob
Yenisei
Yenisei
Yukon
Yukon
Observed
Simulated
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20. Conclusion and discussion
The VIC model with the recent upgrades to its representation of cold land processes was used to simulate streamflow from the pan-Arctic land area from 1979 to The simulated results for the Arctic’s five largest basins show reasonable agreements with the observed values of discharge and snow cover extent.
We currently run the model over the entire Pan-Arctic domain to estimate the fresh water inflow to the Arctic ocean . The model is further validated in energy fluxes, snow water equivalent, and soil freezing/thawing depth using the observed data.
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21. Thank you!
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