Regina Archaeological Society

Published: March 15, 2016

Environmental and Archaeological Research Using
Trees Rings – Dave Sauchyn, U of R
Regina Archaeological Society, 15 March 2016
Vilupulli Church, Isla de Chiloé

 

The Principle of Crossdating
The outer growth of dead trees crossdates with inner portions of living trees living tree
dead wood
archeological wood
Timbers from Farwell’s Trading Post
For Parks Canada (Donalee Deck)
Results: The
timbers were
from trees
dating to 1715-
1853
Timbers from Fort Edmonton
For Royal Alberta Museum (Jack Brink)
Short (40 yrs) complacent
ring-width series
Long (174 yrs) sensitive
ring-width series
Note: final year often not preserved
sensitivity
Most likely harvesting dates of 30 timbers
early1920s:
construction
of the Walter
Barn
1820s:
relocation of
Ft Edmonton
1790s:
construction of
Ft Edmonton

Trees are part of the hydrological cycle

Kootenay Plains Index Chronology
641-2012

Semi-automated image analysis and measurement of tree rings
Calibration Curve, Bow River Model #2, 1525-2004
Bow River at Stoney Trail, Calgary
Mean Water Year Flow (m3/s) South Saskatchewan River
at Medicine Hat, 1108-2010
Cycles in the tree rings
“I found looking at the
tree-ring growth, that
there’s an approximate
60-year weather cycle in
this country, but 60 years
isn’t definite, it could be
70 years and it could be
even less, with weather
there’s nothing written in
stone.”
Reno Welsch, Upper Tennessee
Creek, Alberta, 04/09/2012
Pacific
Decadal
Oscillation
Cooking Lake, September 2008

El Niño remote impacts: Teleconnections
La Niña teleconnections have the opposite effect
Neelin, 2011. Climate Change and Climate Modeling, Cambridge UP
“In order to expand The
City’s understanding of
historical drought
conditions it is important
to reevaluate historical
drought using tree ring
analysis historically
conducted by the David
Sauchyn (University of
Saskatchewan [sic])”
Address Information Gaps:
1 departure from a 1961-90 baseline
Sustained Historical and Pre-Settlement Droughts, SSRB
0
2
4
6
8
10
12
14
16
1400
1425
1450
1475
1500
1525
1550
1575
1600
1625
1650
1675
1700
1725
1750
1775
1800
1825
1850
1875
1900
1925
1950
1975
2000
Annual Volume (1,000,000 cubic decameters)
Year
Recontructed natural annual flow
Alberta’s approx. share under apportionment
Allocations in Bow, Oldman and South Saskatchewan River Basins
Alberta consumption and and storage in a very wet year (1995)
Future Alberta consumption and storage in a very wet year (1995)
Alberta consumption and storage in a very dry year (2001)
Future Alberta consumption and storage in a very dry year (1949)
Reference
Axelson, Jodi N., David J. Sauchyn, and Jonathan Barichivich.
2009. New reconstructions of streamflow variability in the South
Saskatchewan River Basin from a network of tree ring
chronologies, Alberta, Canada. Water Resources Research 45.
Approx. storage capacity
(evaporation loss factored in)
Doug Ohrn, Alberta Environment
Since August 2006, the Alberta government no longer
accepts applications for new allocations of water in the
Oldman, Bow, and South Saskatchewan sub-basins.
“to inform future stages of planning of a
proposed oil sands mining project”
• EPCOR Water Canada provides water, wastewater, and
distribution services to more than 50 communities
• Traditional planning would consider flow characteristics of
the raw water streams as “knowns” in the system.
On May 2nd [1796] William Tomison wrote to James Swain
that furs could not be moved as
“there being no water in the river.”
A Dry Oasis: The Canadian Plains in late Prehistory
James Daschuk
•Climate change beginning in the mid-13th century triggered a largescale abandonment of cultivation and reorientation to large- scale bison
hunting in the grasslands from Texas to the Canadian border.
•The inhabitants of the dry landscape of western Saskatchewan and
Alberta developed a water management strategy that buffered them from
the effects of even long-term drought…. Beaver ponds purposely
maintained through non-exploitation served as dependable water sources
for groups even during periods of extended drought.
•During the most lengthy drought periods, when water could not be
maintained in tributaries, human, bison and beaver populations would
have all sought refuge along main channels of waterways.
.
Mean Water Year Flow (m3/s) South Saskatchewan River
at Medicine Hat, 1108-2010