Published: October 31, 2003
Dave Sauchyn, Ph.D., P.Geo
Prairie Adaptation Research
Collaborative, U of R
Vulnerability to Landslide Risk and Climate
Change Workshop
Vancouver, October 31, 2003
Landslide Risk and Climate Change
in the Interior Plains
The Prairie Adaptation Research Collaborative
is a facilitative, interdisciplinary research
network established to understand the
potential impacts of climate change on the
Canadian Prairie Provinces and conduct
research necessary to develop appropriate
adaptation strategies.
www.parc.ca
Slumgullion earth flow, San Juan Mountains, Colorado
Front Ranges
Alberta Rockies
Arm River valley, Saskatchewan
Swift Current Creek valley, Saskatchewan
Pollen
zone
years
BP
Paleoclimate relative to
present
0
V present climate
cooler
3200
IV moister
4500
III drier and warmer
5100
II much drier and warmer
7700
I drier and warmer
9120
1750 1800 1850 1900 1950 2000
-300
-200
-100
0
100
1750 1800 1850 1900 1950 2000
-200
0
200
400
600
June – July Precipitation
Medicine Hat, Alberta, 1754-2001
August – July Precipitation,
Havre, Montana, 1727-2001
Departures From Median Precipitaton
Epoch Formation Thickness (m) Hydraulic
Conductivity
(m/day)
Oligocene Cypress Hills 15 – 76 100
Paleocene Ravenscrag 70 + 10-4
Upper Cretaceous Frenchman 3 – 45 + 10-1
Upper Cretaceous Battle 6 – 9 10-1
Upper Cretaceous Whitemud 10 – 14 10-1
Upper Cretaceous Eastend 21 – 37 10-1
Upper Cretaceous Bearpaw 285 – 305 10-5
Police Point Landslide
0.0
40.0
80.0
120.0
160.0
200.0
0.0
20.0
40.0
5 15 19 28 31 27 3
May June
erosion (cm)
deposition (cm)
precipitation (mm)
1996
2 6
July
The Eureka River landslide and dam, Peace River
Lowlands, Alberta
B.G.N. Miller and D.M. Cruden
Can. Geotech. J. Vol. 39, 2002
The Eureka River landslide of June 1990, at 50 Mm3
,
is one of the largest historical landslides on the
Interior Plains of Canada. It is one of seven large
translational landslides to have occurred in the Peace
River Lowlands within the last 65 years. Each
landslide occurred in Quaternary sediments deposited
within a preglacial valley. Each landslide formed a
dam. The landslide dam was over 20 m high, forming
a lake exceeding 8 km in length.
The 1939 landslide on the west wall of the
Montagneuse River valley, 1300 m long,
1400 m wide, and 80 m thick with a
volume of 76 x 106 m3, is the largest
historic rapid landslide on the Interior Plains of Canada. It
lasted about a minute, dammed the river, and formed a
reservoir 1.5 km long. The Montagneuse River was pushed
eastward. The main scarp has been substantially modified
by earth flows and slides. Landslides in the Montagneuse
River valley coincide with the Shaftesbury buried preglacial
channel of the Peace River. The surfaces of rupture of five
historic landslides in the Peace River Lowland follow clays
deposited in preglacial channels, confirming that these
deposits may be hazardous when eroded.
The 1939 Montagneuse River
landslide, Alberta
D.M. Cruden, Z-Y. Lu, and S. Thomson
Can. Geotech. J. Vol. 34, 1997
Thirty-five years of activity at the Lesueur landslide,
Edmonton, Alberta
D.M. Cruden, A.E. Peterson, S. Thomson, and P. Zabeti
Can. Geotech. J. 39: 266–278, 2002
The Lesueur landslide occurred on 3 September 1963
on the outside of a meander of the North
Saskatchewan River in northeast Edmonton. The
displaced volume was 0.76 Mm3 of Pleistocene
deposits and underlying Upper Cretaceous mudstones.
The trigger of the landslide is believed to be
accelerated erosion of the slope toe caused by
dumping of mine waste on the inside of the meander.
Surveys in 1964, 1971, 1992, 1995, 1997, and 1998
have documented continued slope movements.
North Saskatchewan River, Edmonton
1. Unexpected landslides at various locations
resulting from wet summer conditions.
2. Increased costs on various tendered construction
contracts.
3. Carry-over of various construction projects to
2001-02 fiscal year.
4. Increased winter gravel crushing and haul
5. Positions transferred.
Annual Report 1999 – 2000
Saskatchewan Highways and Transportation
Explanation of significant differences between
budget and actual:
Aridity (P/PET), 2050, CGCM2
Extreme precipitation events are likely to
become more frequent
50
55
60
65
70
75
80
85
90
95
Event recurrence time (Years)
Size of event (mm)
10 20 30 40 50 60 70 80
1985
2050
2090
Extreme Precipitation Events (Canada)
Extreme rainfalls in southern Saskatchewan
Buffalo Gap, May 30, 1961
• one-hour: 258 mm
Parkmanm, August 3-4, 1985
• six-hour: 267 mm
• 12-hour: 362 mm
• 24-hour: 381 mm
Vanguard, July 3, 2000
• eight-hour: 334-387 mm
Note: all data from bucket surveys