scholarly journals Debris flow hazard in the Canadian Rocky Mountains: observations on the geomorphology of montane fans and a methodology for the identification of debris flow hazard on fans in geologically similar northern upland areas

1987 ◽  
Author(s):  
L E Jackson
Keyword(s):  
Debris Flow ◽  
Rocky Mountains ◽  
Canadian Rocky Mountains ◽  
Debris Flow Hazard

Unusual disturbance: forest change following a catastrophic debris flow in the Canadian Rocky Mountains

2006 ◽  
Vol 36 (9) ◽  
pp. 2204-2215 ◽  
Author(s):  
Stewart B Rood
Keyword(s):  
Debris Flow ◽  
Populus Tremuloides ◽  
Rocky Mountains ◽  
Forest Type ◽  
Populus Trichocarpa ◽  
Heavy Rain ◽  
Extreme Weather Events ◽  
Canadian Rocky Mountains ◽  
Forest Change ◽  
Riparian Tree

Trees are often well adapted to periodic physical disturbances such as fires or floods. However, I investigated forest response to an extremely unusual disturbance event. Following heavy rain in June 1995 a catastrophic debris flow from Vimy Peak in the Canadian Rocky Mountains terminated as an alluvial debris fan that plowed through a trembling aspen (Populus tremuloides Michx.) grove. I analyzed the site over a decade to monitor forest response and determine whether there would be recolonization to the prior forest type. In contrast to my expectation, aspen recolonization did not occur; instead, black cottonwoods (Populus trichocarpa Torr. & Gray) colonized the site. These originated from seedlings and not through clonal propagation, and by 2004, black cottonwoods composed 99% of the saplings and were typically 0.6–1.4 m tall with a density of about 1/m2. The debris fan dramatically changed the physical environment, which partly resembled a floodplain depositional zone and was colonized by the regionally dominant riparian tree. I propose the concept of foreign disturbance to recognize an unusual disturbance that an organism would very rarely experience and thus to which it is unlikely to be adapted. In this example the disturbance produced an abrupt transition to an alternative forest type and this response may provide insight into forest response to other unusual disturbances, such as extreme weather events, that might increase with climate change.

Process and discharge estimation in ephemeral channels, Canadian Rocky Mountains

1984 ◽  
Vol 21 (9) ◽  
pp. 1050-1060 ◽  
Author(s):  
Joseph R. Desloges ◽  
James S. Gardner
Keyword(s):  
Debris Flow ◽  
Rocky Mountains ◽  
Canadian Rocky Mountains ◽  
Alluvial Channels ◽  
Channel Processes ◽  
Cross Sectional ◽  
Ephemeral Channels ◽  
Multiple Process ◽  
Instantaneous Discharge ◽  
Discharge Estimation

Process determinations and discharge estimates are made for 10 steep alpine channels in the Front and Main ranges of the southern Canadian Rocky Mountains. The catchments, which range in size from 0.17 to 1.13 km2, are sufficiently small that their runoff patterns are dominantly ephemeral and are characterized by processes that include water floods, debris flows, and snow avalanches.Longitudinal and cross-sectional channel profiles demonstrate the importance of bedrock control and the influence of one or more dominant processes. Debris flow channels have been partially scoured by water floods, and avalanche and debris flow sediments are noted in modified alluvial channels. The distribution and sorting of sediments support the multiple-process origin of specific channels or channel reaches.The discrimination of channel processes is essential for estimates of channel discharge. Slope/area and competence methods employed in fluvially dominated reaches of the 10 channels yield maximum instantaneous discharge estimates of between 1.1 and 12.2 m3 s−1. These discharges are generally not representative of the potential volumes of water and sediment released from the channels because of augmentation by both debris flow and avalanche processes. The design of roads and railways traversing these channels requires consideration of a range of processes of varying magnitudes.

Late Pleistocene subaerial debris-flow facies of the Bow Valley, near Banff, Canadian Rocky Mountains

Sedimentology ◽  
1988 ◽  
Vol 35 (3) ◽  
pp. 465-480 ◽  
Author(s):  
NICHOLAS EYLES ◽  
CAROLYN H. EYLES ◽  
A. MARSHALL McCABE
Keyword(s):  
Debris Flow ◽  
Late Pleistocene ◽  
Rocky Mountains ◽  
Canadian Rocky Mountains

Wildfires in the southern Canadian Rocky Mountains and their relationship to mid-tropospheric anomalies

1993 ◽  
Vol 23 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
E.A. Johnson ◽  
D.R. Wowchuk
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Large Scale ◽  
Fire Frequency ◽  
Fuel Moisture ◽  
Large Fire ◽  
Canadian Rocky Mountains ◽  
Area Burned ◽  
Upper Level ◽  
Moisture Conditions

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

Canadian Rocky Mountains

1903 ◽  
Vol 21 (6) ◽  
pp. 685
Author(s):  
J. Norman Collie
Keyword(s):  
Rocky Mountains ◽  
Canadian Rocky Mountains
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