1. The frequency, severity and causes
of extreme droughts in the
Winnipeg River basin
Scott St. George
Geological Survey of Canada

2. 2003

7. geosciences

8. EARTH SCIENCES RANKINGS
1. California Institute of Technology
2. Massachusetts Institute of Technology
3. Stanford University
4. University of California - Berkeley
5. Columbia University
6. University of Michigan
7. Pennsylvania State University
8. University of Arizona
9. Harvard University
10. University of Texas - Austin
US News and World Report, 2006

9. 2008

12. The frequency, severity and causes
of extreme droughts in the
Winnipeg River basin
Scott St. George
Geological Survey of Canada

13. FU N DI N G A GE NCI ES
Manitoba Hydro
Manitoba Geological Survey
Natural Resources Canada
National Science and Engineering Council of Canada
Prairie Adaptation Research Collaborative

14. WINNIPEG RIVER STREAMFLOW

17. South Saskatchewan River at Saskatoon
relative change
in summer flow
Schindler and Donahue, 2006, PNAS

20. LOW HIGH
HIGH LOW
St. George, 2007, Journal of Hydrology

21. trends

22. Annual discharge since 1924

23. Annual discharge since 1924
+ 58%
NO TREND
+ 52%
+ 46%
NO TREND
NO TREND
NO TREND
NO TREND

24. “
For monthly and annual
average flow based on
adjusted disaggregated flow
data, upward trends are
detected for the entire period
from 1912 to 2006.
Liu, 2007

25. Winnipeg River
≠ Saskatchewan River
Western Hudson Bay
Canadian Prairies

26. 1892

27. what happened
before that?

28. paleoclimatology
the study of the Earth’s climate prior to the
period of instrumental measurements

31. R ECO R D S F RO M ANCIEN T TR EES

38. never trust
one tree

39. 975
trees

40. 286,420
tree rings

42. Photograph courtesy Kurt Kipfmueller

43. 1783

45. 755 m3/s
847 m3/s
809 m3/s
770 m3/s
823 m3/s
787 m3/s
901 m3/s
3

46. TREE R I N G S A N D P R A IRI E DRO UG HT

47. Martin-Philippe Girardin
Canadian Forest Service
Greg Pederson
United States Geological Survey
Glen MacDonald David Sauchyn Emma Watson
UCLA University of Regina Environment Canada
Erik Nielsen Jacques Tardif
Manitoba Geological Survey University of Winnipeg

48. 2,860
trees

49. Prairie tree-ring network

50. 755 m3/s
847 m3/s
809 m3/s
770 m3/s
823 m3/s
787 m3/s
901 m3/s
3

52. CLIMATE
direct
HYDROLOGY

53. CLIMATE
direct direct
PROXIES HYDROLOGY

54. CLIMATE
direct direct
PROXIES HYDROLOGY
indirect

56. “ This
must
be
voodoo. ”
Anonymous water
manager

57. How good are
drought records from
tree rings?

58. geography matters

59. Prairie tree-ring network

60. Palmer
Drought
Severity
Index

61. 10 southern Alberta 3
2
5
1
Ringwidth
PDSI
0 0
-1
-5
-2
-3
-10
1900 1920 1940 1960 1980 2000
St. George et al., (accepted), Journal of Climate
Year (A.D.)

62. 10 southern Alberta 3
2
5
1
Ringwidth
PDSI
0 0
-1
-5
r = 0.62 -2
-3
-10
1900 1920 1940 1960 1980 2000
St. George et al., (accepted), Journal of Climate
Year (A.D.)

63. northwestern Ontario 3
6
2
4
1
Ringwidth
2
PDSI
0 0
-2 -1
-4 r = 0.40
-2
-6
-3
1900 1920 1940 1960 1980 2000
St. George et al., (accepted), Journal of Climate Year (A.D.) 59

64. 755 m3/s
847 m3/s
809 m3/s
770 m3/s
823 m3/s
787 m3/s
901 m3/s
3

66. How bad has
drought been?

67. ‘Now’ ‘Then’
(AD 1900 - present) (AD 1500 - 1900)

69. 1783

70. How bad has
drought been?

71. 1910

73. 1720s

74. How bad has
drought been?

75. more persistent
more severe eds
ter sh
me wa
in so

77. 73

78. 74

79. P R O D U C T S AND APPLICATIONS

80. data

82. WORLD
D ATA C E N T E R f o r
PA L E O C L I M AT O L O G Y

83. Publications

84. Scott St. George
Streamflow in the Winnipeg
River basin, Canada: trends,
extremes and climate linkages
Journal of Hydrology 332, 396-411, 2007

85. Scott St. George, Dave Meko and Mike Evans
Regional tree growth and
inferred summer climate in
the Winnipeg River basin,
Canada since AD 1783
Quaternary Research 70, 158-172, 2008

86. Scott St. George, Dave Meko, Martin Girardin, Erik
Nielsen, Greg Pederson, Dave Sauchyn, Jac Tardif,
and Emma Watson
The tree-ring record of
summer drought in the
Canadian Prairies
Journal of Climate, in press

89. does the past
really matter?

92. 3
main
applications

93. climate change
YOU CAN TOUCH

94. BENCHMARKS
for recent events and trends

95. starting points for
‘paleo’ scenarios
91

96. VIC BAKER
UNIVERSITY OF ARIZONA

97. “ HAPPEN AGAIN
Common sense holds that what has really happened
CAN
VIC BAKER
UNIVERSITY OF ARIZONA

98. F U TURE DI REC TION S

99. Prairie tree-ring network

100. northwestern Ontario 3
6
2
4
1
Ringwidth
2
PDSI
0 0
-2 -1
-4 r = 0.40
-2
-6
-3
1900 1920 1940 1960 1980 2000
St. George et al., (accepted), Journal of Climate Year (A.D.) 95

101. Can we do
better ?

102. drought
f ring width

103. drought
f ring width
ring chemistry

104. drought
f ring width
ring chemistry
ring density

106. CLIMATE
direct direct
PROXIES HYDROLOGY
indirect

107. HYDROLOGY

111. ?
climate change
geological

113. The frequency, severity and causes
of extreme droughts in the
Winnipeg River basin
Scott St. George
Geological Survey of Canada