Transcript Stream flow simulations on Lena basin

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 98195
E-mail: [email protected]
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Outline
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Background
2.
Model description
3.
Data sources
4.
Streamflow simulations
5.
Conclusion and discussion
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Background
1.
The importance of freshwater inflow to the
ocean systems .
2.
The unique features of arctic land-surface
hydrology.
3.
The potential effects of climate change on the
runoff of northern rivers.
4.
The need of appropriate hydrologic models for
runoff prediction from Pan-Arctic terrestrial
domain.
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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 macroscale hydrological model.
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Cold land processes
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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Data sources

Meteorological forcings
Daily time series (1979-1999) 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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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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Pan-Arctic Drainage Basins / mask file
Yukon
Mackenzie
Lena
Lena
Yenisei
Ob
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Arctic river network over 100km grid system
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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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Model Soil Parameters
Basin
Lena
Yenesei
Yukon
Ob
Mackenzie
Infiltration parameter
bi
0.5
0.5
0.5
0.05~0.1
0.1
Top layer depth (m)
0.05~0.1
0.1
0.1
0.5
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
0.2~0.3
1
1
Soil
parameter
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Lena
Aldan at Verhoyanski Perevoz (Area:696000.00 km2)
Lena at Kusur (Area:2430000.00 km2)
Observed
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Mean monthly hydrograph (1979-1999)
Lena at Kusur
Simulated
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Yenisei
Nizhnyaya Tunguska at Bol’shoy
Porog, Yenisei (Area: 447000.00 km2)
Mean monthly hydrograph (1979-1990)
Yenisei at Igarka (Area: 2440000.00 km2)
Mean monthly hydrograph (1979-1998)
Observed
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Simulated
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Ob
Ob at Prokhorkino (Area: 738000.00 km2)
Ob at Salekhard (Area: 2430000.00 km2)
Observed
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Mean monthly hydrograph (1979-1994)
Mean monthly hydrograph (1979-1998)
Simulated
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Mackenzie
Mackenzie at Arctic Red River (Area: 738000.00 km2)
Mean monthly hydrograph (1979-1991)
Yukon
Yukon R NR Stevens Village AK (Area:508417.50 km2)
Observed
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Yukon R NR Stevens Village AK
Simulated
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Indigirka
Yana
Indigirka at Vorontsovo, Lena (Area: 305000.00 km2)
Yana at Ubileinaya, Lena (Area: 224000.00 km2)
Observed
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Simulated
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Mean number of days with snow
1980-1999
1980-1989
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1990-1999
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Fraction of area covered by snow
Lena
Ob
Observed
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Simulated
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Mean monthly fraction of area covered by snow
Lena
Lena
Mackenzie
Mackenzie
Ob
Ob
Yenisei
Yenisei
Yukon
Yukon
1980-1989
1990-1999
Observed
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Simulated
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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 1999. 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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Thank you!
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