Thawing of Permafrost Peatland and
Hydrological Implications
Masaki Hayashi1, Bill Quinton2, Alastair McClymont1,
Larry Bentley1, Brendan Christensen1
1Geoscience,
University of Calgary
2Geography & Env. Studies, Wilfrid Laurier University
Prediction of Permafrost Thaw, 1990-2090
Scotty Creek
Hay River
Lowland
Model Assumptions
• Vertical energy transfer
• Large (50 km) grids
• No lateral flow of water
and energy
Reality (Scotty Creek)
pink: complete thawing
Zhang et al. (2008.lake
Geophys. Res.
Lett., 35: L02502)
peat plateau
isolated bog
connected bog
channel fen
1 km
Annual Total Basin Runoff near Ft. Simpson
precipitation (mm)
annual runoff (mm)
Four Rivers (150-1,900 km2), Similar Landcovers
400
300
200
Birch
Jean-Marie
Blackstone
Scotty
Runoff = Total flow / Drainage area
100
0
1970
1980
1990
2000
2010
Ft. Simpson precip.
600
400
200
0
1970
1980
1990
2000
2010
flat bog
peat plateau
channel fen
Peat Plateaus Have Permafrost Cores
channel fen
Water flows over
frozen peat.
bog
permafrost
Frost Table in Late August 2006
GS: ground surface
FT: frost table
relative elevation (m)
1
ground surf.
0.5
0.5 m
0
0.9 m
-0.5
frost table
-1
-1.5
0
10
20
30
distance from fen (m)
40
Differential Thawing by Conduction
0.5
ground srf.
zf
l (W m-1 K-1)
T = Ts
Qm
T=0
frost table
Conduction dominates heat flux.
Qm = lb (Ts – 0) / zf
0.4
0.3
0.2
0.1
Measured
de Vries Eqn.
0.4 0.5 0.6 0.7 0.8
lb : bulk thermal conductivity
water content
Wet spots thaw faster.
Hayashi et al. (2007, Hydrol. Proces. 21: 2610-2622)
2D Survey of Frost Table (FT)
June 12, 2006
ground
surf.
FT
• FT measured using FT probe on 0.25 m grids.
• Subsurface flow simulation: 15 mm of rain added.
Boussinesq equation is numerically solved.
Wright et al. (2009, Water Resour. Res. 45: W05414)
Electrical Resistivity Imaging (ERI)
fen
bog
0m
0m
5
fen
20
FT
plateau
40
permafrost
10
15
20
resistivity (W m)
60
bog
80
unfrozen peat
clay
102
103
104
ERI Line 1: Peat Plateau Transect
depression
20 m
0
2
30
40
50
60
4
0m
0m
5
fen
20
FT
plateau
40
permafrost
10
15
20
resistivity (W m)
60
bog
80
unfrozen peat
clay
102
103
104
ERI Line 2: Cross-Bog Transect
100m
fen
0m
0m
isolated bog
20
40
bog
60
80
5
10
15
20
clay
clay
sand lens
resistivity (W m)
102
103
104
Conceptual Model of Permafrost Thaw
peat plateau
1. Thinning of canopy.
 Increase in radiation
energy input.
2. Local thawing.
 Water-energy feedback
causes further thawing.
3. Wet condition prevents
trees from growing back.
 New bog forms.
unsaturated, thawed peat
saturated, thawed peat
saturated, frozen peat
1
2
preferential thaw
new bog
3
Delineation of Peat Plateau on Aerial Images
1977
200 m
Quinton et al. (2011, Hydrol. Proces., 25: 152)
Delineation of Peat Plateau on Aerial Images
2008
Peat Plateau Area
1977: 53%
2008: 43%
200 m
Quinton et al. (2011, Hydrol. Proces., 25: 152)
Changes Evident on the Ground
Aug. 2002
July 2010
Datalogger
Datalogger
Modelling Peat Plateau Runoff
Hydraulically
equivalent plateau
Drainage of groundwater controlled by:
- Radius
- Gradient
- Ksat distribution
- Frost-table depth
200 m
Similar to MESH, but the
moving FT is the challenge.
Coupled Permafrost-Hydrology Model
for Circular Peat Plateau
vertical transfer
lateral drainage
Northern Ecosystem
Soil Temperature
(NEST) model
Zhang et al. (2008)
Simple Fill and Spill
Hydrology (SFASH)
model
Wright et al. (2009)
frost table (m)
NEST-SFASH Preliminary Results
0
0.2
0.4
0.6
0.8
water flux (mm/d)
40
20
0
6
4
2
0
simulated
observed
J F M AM J J AS O N D J F M AM J J AS O N D
rain
2009
2010
snow melt
runoff
J F M AM J J AS O N D J F M AM J J AS O N D
2009
2010
L
L
L
L
L
L
L
L
Challenges and the Way Forward
1. Storage and flow of runoff water in the fen-bog
network  Basin-scale hydrological model.
2. Incorporate lateral thawing of permafrost in longterm model simulation (e.g. 50 years).
3. Ecology-hydrology feedback processes.
IP3 Legacy
1. Scotty Creek research basin
2. Close collaboration with the local First Nation.
3. WLU-Northwest Territories Partnership for
Research and Training (2010-2020, $10M project).
Acknowledgements
People
Nicole Wright, Laura Chasmer, Chris Hopkinson, Tyler
Veness, Rob Schincariol, and many others
Funding
IP3 Network
International Polar Year
Natural Sciences and Engineering Research Council
Canada Research Chair Program
Environment Canada Science Horizons Program
Logistical Support
Water Survey of Canada
Environment Canada (NWRI)
Liidlii Kue First Nations