final presentation to manitoba hydro

The frequency, severity and causes of extreme droughts in the

Winnipeg River basin

Scott St. GeorgeGeological Survey of Canada

2003

geosciences

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

EARTH SCIENCES RANKINGS

US News and World Report, 2006

2008

The frequency, severity and causes of extreme droughts in the

Winnipeg River basin

Scott St. GeorgeGeological Survey of Canada

FUNDING AGENCIES

Manitoba Hydro

Manitoba Geological Survey

Natural Resources Canada

National Science and Engineering Council of Canada

Prairie Adaptation Research Collaborative

WINNIPEG RIVER STREAMFLOW

relative change in summer flow

Schindler and Donahue, 2006, PNAS

South Saskatchewan River at Saskatoon

LOW

HIGH LOW

HIGH

St. George, 2007, Journal of Hydrology

trends

Annual discharge since 1924

Annual discharge since 1924

NO TREND

NO TREND

NO TREND

NO TRENDNO TREND

+ 46%

+ 52%

+ 58%

““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

Western Hudson Bay

Saskatchewan River≠Winnipeg River

Canadian Prairies

1892

what happened

before that?

paleoclimatologythe study of the Earth’s climate prior to the period of instrumental measurements

RECORDS FROM ANCIENT TREES

never trust one tree

975trees

286,420tree rings

Photograph courtesy Kurt Kipfmueller

1783

755 m3/s847 m3/s809 m3/s770 m3/s823 m3/s787 m3/s901 m3/s840 m3/s

TREE RINGS AND PRAIRIE DROUGHT

Martin-Philippe Girardin Canadian Forest Service

Greg Pederson United States Geological Survey

Erik Nielsen Manitoba Geological Survey

Emma WatsonEnvironment Canada

Glen MacDonaldUCLA

David Sauchyn University of Regina

Jacques Tardif University of Winnipeg

2,860trees

Prairie tree-ring network

755 m3/s847 m3/s809 m3/s770 m3/s823 m3/s787 m3/s901 m3/s840 m3/s

HYDROLOGY

CLIMATE

direct

HYDROLOGY

CLIMATE

direct

PROXIES

direct

HYDROLOGY

CLIMATE

direct

indirectPROXIES

direct

This must be

voodoo.Anonymous water

manager

“

”

How good are drought records from

tree rings?

geography matters

Prairie tree-ring network

PalmerDroughtSeverityIndex

1900 1920 1940 1960 1980 2000

Year (A.D.)

-10

-5

0

5

10PD

SI

-3

-2

-1

0

1

2

3

Rin

gwid

th

southern Alberta

St. George et al., (accepted), Journal of Climate

1900 1920 1940 1960 1980 2000

Year (A.D.)

-10

-5

0

5

10PD

SI

-3

-2

-1

0

1

2

3

Rin

gwid

th

r = 0.62

St. George et al., (accepted), Journal of Climate

southern Alberta

1900 1920 1940 1960 1980 2000

Year (A.D.)

-6

-4

-2

0

2

4

6

PD

SI

-3

-2

-1

0

1

2

3

Rin

gwid

th

59

northwestern Ontario

St. George et al., (accepted), Journal of Climate

r = 0.40

755 m3/s847 m3/s809 m3/s770 m3/s823 m3/s787 m3/s901 m3/s840 m3/s

How bad has drought been?

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

1783

How bad has drought been?

1910

1720s

How bad has drought been?

more persistentmore severe

in some watersheds

73

74

PRODUCTS AND APPLICATIONS

data

W O R L DD ATA C E N T E R f o rPA L E O C L I M AT O L O G Y

Publications

Scott St. George

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

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

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

does the past really matter?

3mainapplications

YOU CAN TOUCHclimate change

BENCHMARKSfor recent events and trends

91

‘paleo’ scenariosstarting points for

VIC BAKER UNIVERSITY OF ARIZONA

“Common sense holds that what has really happened

CAN HAPPEN AGAIN“

VIC BAKER UNIVERSITY OF ARIZONA

FUTURE DIRECTIONS

Prairie tree-ring network

1900 1920 1940 1960 1980 2000

Year (A.D.)

-6

-4

-2

0

2

4

6

PD

SI

-3

-2

-1

0

1

2

3

Rin

gwid

th

95

northwestern Ontario

St. George et al., (accepted), Journal of Climate

r = 0.40

Can we do

better?

ring widthfdrought

ring widthfdrought

ring chemistry

ring widthfdrought

ring chemistry

ring density

HYDROLOGY

CLIMATE

direct

indirectPROXIES

direct

HYDROLOGY

?climate changegeological

The frequency, severity and causes of extreme droughts in the

Winnipeg River basin

Scott St. GeorgeGeological Survey of Canada