Slides supporting a presentation at the University of Stockholm's Department of Physical Geography and Quaternary Geology.
Canada is rightly considered a water-rich nation, but persistent drought is still a leading source of risk to agriculture and energy production, particularly in the dry western interior. During the 20th century, the Canadian Prairies were less affected by decadal-scale shifts in hydroclimate than other places in North America, but the relative brevity of instrumental records makes it difficult to evaluate the potential duration and geographic scope of severe drought. Tree-ring and other proxy records show that that parts of the the Canadian Prairies experienced, relatively recently, summer droughts that were more intense and more long lasting than those observed in instrumental records. These past droughts serve as alternative worst-case scenarios that water managers can use to evaluate the resilience of their systems to conditions outside their personal or institutional experience. Comparing regional tree-ring records against the broader North American network also indicates that studies investigating the patterns and mechanisms of past drought across the continent need to consider the potential effects of seasonality biases in paleoclimate proxies.
5. Renewable water resources, by country
Brazil
Russia
Canada
USA
China
India
Columbia
Peru
Zaire
0 2,000 4,000 6,000
km3/y
Source: Shiklomanov and Rodda, 2003
17. Past dynamics ➜ Future behavior
PRESENT
PAST FUTURE
Precipitation Drought risks
Discharge Sustainable yield
Lake level Flood hazards
Soil moisture
18.
19. DECADAL VARIABILITY AND PRAIRIE WATER
How important is decadal-to-multidecadal variability to the
1 hydroclimate of western Canada and North America?
20. DECADAL VARIABILITY AND PRAIRIE WATER
How important is decadal-to-multidecadal variability to the
1 hydroclimate of western Canada and North America?
PRAIRIE DROUGHTS SINCE AD 1500
What tree rings tell us about severity, persistance and
2 dynamics of past droughts on the Prairies.
35. CLIMATE HISTORY OF CANADA
Younger Demise of Laurentide
Dryas Ice Sheet
20 16 12 8 4 0
THOUSANDS OF
YEARS AGO
Final Drainage
of Lake Agassiz
LAST GLACIAL MODERN
MAXIMUM OBSERVATIONS
39. MEGADROUGHT
intensity at least equivalent to modern multiyear droughts
duration longer than the several years to decade thereof
Seager et al., Journal of Climate, 2008
40.
41. Martin-Philippe Girardin
Canadian Forest Service
Greg Pederson
United States Geological Survey
David Sauchyn
Glen MacDonald Emma Watson
UCLA University of Regina Environment Canada
Erik Nielsen Jacques Tardif
Manitoba Geological Survey University of Winnipeg
56. southern Alberta
10
3
2
5
1
Ringwidth
PDSI
0 0
-1
-5
-2
-3
-10
1900 1920 1940 1960 1980 2000
Year (A.D.)
St. George et al., Journal of Climate, 2009
57. southern Alberta
10
3
2
5
1
Ringwidth
PDSI
0 0
-1
-5
r = 0.62 -2
-3
-10
1900 1920 1940 1960 1980 2000
Year (A.D.)
St. George et al., Journal of Climate, 2009
58. Drought history - western Prairies
PDSI
6
4 observations
2
0
-2
tree rings
-4
-6
1500 1600 1700 1800 1900 2000
Year (AD)
St. George et al., Journal of Climate, 2009
59. MEGADROUGHT
intensity at least equivalent to modern multiyear droughts
duration longer than the several years to decade thereof
Seager et al., Journal of Climate, 2008
60. 58 oN
1718 - 1722
56 oN
54 oN
52 oN
50 oN
48 oN
oW
90
114 oW oW
96
o o
108 W 102 W
Ringwidth anomaly
(deviations)
−2 −1 0 1 2
-2 0 +2
64. Drought history - eastern Prairies
PDSI
4
observations
2
0
-2
tree rings
-4
1500 1600 1700 1800 1900 2000
Year (AD)
St. George et al., Journal of Climate, 2009
76. “ This
must
be
voodoo.”
Anonymous
water manager
77.
78.
79. davidstahle edwardcook malcolmcleveland matttherrel
davidmeko henrigrissino-mayer emmawatson brianluckman
Tree-ring data document
16th century megadrought
over North America
EOS 81, p121, 2000
80. davidstahle edwardcook malcolmcleveland matttherrel
davidmeko henrigrissino-mayer emmawatson brianluckman
Tree-ring data document
16th century megadrought
over North America
but not Canada
EOS 81, p121, 2000
81.
82. 100%
MORE CERTAIN
Woodhouse et al., 2006
Meko et al., 2001
80% Upper Colorado River
Sacramento River
Meko et al., 2007
Colorado River
Woodhouse, 2007
Middle Boulder Creek
60% Case and MacDonald, 2003
explained
Saskatchewan River
Beriault and Sauchyn, 2006
Churchill River
Bonin and Burn, 2005
variance Athabasca River
40%
Gedalof et al., 2007
Watson and Luckman, 2005
Columbia River
Bow River
20%
LESS CERTAIN
0%
Canada USA
84. Medicine Hat, Alberta
25 80
20
15 60
Precipitation mm)
Temperature (°C)
10
5 40
0
-5 20
-10
0
-15
Jan Mar May Jul Sep Nov
Source: Environment Canada, Adjusted Historical Canadian Climate Data, 1895 – 2006