The Canadian Prairies are Canada’s most significant dryland area and regional drought has an enormous impact on agricultural and energy production and the reliability of public water supplies. Many water managers are turning to tree rings and other natural indicators to expand their perspective on regional hydrology.
Prepared for the Department of Geography, University of Lethbridge, April 3, 2009.
10. Past dynamics ! Future behavior
PRESENT
PAST FUTURE
Precipitation Drought risks
Discharge Sustainable yield
Lake level Flood hazards
Soil moisture
11. stationarity
A stationary time series is free of trends, shifts
or periodicity, and has statistical parameters that
remain constant through time.
12. Christopher Milly, Julio Betancourt, Malin Falkenmark, Robert
Hirsch, Zbigniew Kundzewicz, Dennis Lettenmaier, Ronald Stouffer
Stationarity is dead: whither
water management?
Science 319, 573-574, 2008
13.
14. South Saskatchewan River at Saskatoon
relative change
in summer flow
Schindler and Donahue, 2006, PNAS
15. Annual discharge since 1924
+ 58%
NO TREND
+ 52%
+ 46%
NO TREND
NO TREND
NO TREND
NO TREND
St. George, Journal of Hydrology, 2007
17. 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
24. TREES AS BIOLOGICAL ARCHIVES
How can records from the annual growth rings of trees be
1 interpreted as indicators of past environmental change?
25. TREES AS BIOLOGICAL ARCHIVES
How can records from the annual growth rings of trees be
1 interpreted as indicators of past environmental change?
PRAIRIE DROUGHTS SINCE AD 1500
What tree rings tell us about severity, persistance and
2 dynamics of past droughts on the Prairies.
30. The trees composing the forest rejoice
and lament with its successes and failures
and carry year by year something of its
story in their annual rings.
A.E. DOUGLASS
36. North American
Tree-Ring
Chronologies
Western species
Ponderosa pine
Douglas-fir
Big cone douglas-fir
High elevation conifer
Mountain Hemlock
Other conifer
Eastern species
White oak group
Hemlock
Baldcypress
Tulip poplar
Overcup oak
Northern red oak
Courtesy David Stahle
37.
38.
39. MEXICO
UNITED STATES
Sonora
Arizona
Baja California
California
Colorado
New Mexico
Nevada
Utah
Wyoming
42. Colorado River Basin Water Management
National Academy of Sciences, 2007
“... studies of past climate...[reveal] many periods
when streamflow was lower than at any time
in the past 100 years of recorded flows. ”
55. Martin-Philippe Girardin
Canadian Forest Service
Greg Pederson
United States Geological Survey
David Sauchyn
Glen MacDonald Emma Watson
University of Regina
UCLA Environment Canada
Erik Nielsen Jacques Tardif
Manitoba Geological Survey University of Winnipeg
60. earlywood latewood
cessation of growth
Photograph: Kevin Anchukaitis
61. “ The growth of trees is undoubtably controlled
more by the movement of water than by the
movement of any other single substance.”
HAL FRITTS
TREE RINGS AND CLIMATE
90. “ The grass in this arid soil, always so scanty, was
now actually swept away by the buffalo, who,
assisted by the locusts had left the country as
bare as if it had been overrun by fire; even at
the edge of Sage Creek we could obtain but very
”
little water for our horses.
JOHN PALLISER, 1859
89
99. Janice Lough and Hal Fritts
The Southern Oscillation and tree rings: 1600 - 1961
Journal of Applied Meteorology 24, 1985
Roseanne D’Arrigo and Gordon Jacoby
A thousand year record of northwestern New
Mexico winter precipitation reconstructed from tree
rings and its relation to El Niño and the Southern
Oscillation
The Holocene 1, 1991
David Stahle and collaborators
Experimental dendroclimatic reconstruction of the
Southern Oscillation
Bulletin of the American Meteorological Society 79, 1998
100. ENSO and Prairie tree rings
correlation with CTI
St. George et al., (2009), Journal of Climate