Debris flow defenses in British Columbia

Author(s):  
Oldrich Hungr ◽  
G. C. Morgan ◽  
D. F. VanDine ◽  
D. R. Lister
Keyword(s):  
Geomorphology ◽  
2010 ◽  
Vol 114 (4) ◽  
pp. 601-613 ◽  
Author(s):  
R.H. Guthrie ◽  
A. Hockin ◽  
L. Colquhoun ◽  
T. Nagy ◽  
S.G. Evans ◽  
...  

Landslides ◽  
2020 ◽  
Vol 17 (4) ◽  
pp. 913-930 ◽  
Author(s):  
Pierre Friele ◽  
Tom H. Millard ◽  
Andrew Mitchell ◽  
Kate E. Allstadt ◽  
Brian Menounos ◽  
...  

AbstractTwo catastrophic landslides occurred in quick succession on 13 and 16 May 2019, from the north face of Joffre Peak, Cerise Creek, southern Coast Mountains, British Columbia. With headscarps at 2560 m and 2690 m elevation, both began as rock avalanches, rapidly transforming into debris flows along middle Cerise Creek, and finally into debris floods affecting the fan. Beyond the fan margin, a flood surge on Cayoosh Creek reached bankfull and attenuated rapidly downstream; only fine sediment reached Duffey Lake. The toe of the main debris flow deposit reached 4 km from the headscarp, with a travel angle of 0.28, while the debris flood phase reached the fan margin 5.9 km downstream, with a travel angle of 0.22. Photogrammetry indicates the source volume of each event is 2–3 Mm3, with combined volume of 5 Mm3. Lidar differencing, used to assess deposit volume, yielded a similar total result, although error in the depth estimate introduced large volume error masking the expected increase due to dilation and entrainment. The average velocity of the rock avalanche-debris flow phases, from seismic analysis, was ~ 25–30 m/s, and the velocity of the 16 May debris flood on the upper fan, from super-elevation and boulder sizes, was 5–10 m/s. The volume of debris deposited on the fan was ~ 104 m3, 2 orders of magnitude less than the avalanche/debris flow phases. Progressive glacier retreat and permafrost degradation were likely the conditioning factors; precursor rockfall activity was noted at least ~6 months previous; thus, the mountain was primed to fail. The 13 May landslide was apparently triggered by rapid snowmelt, with debuttressing triggering the 16 May event.


1985 ◽  
Vol 22 (10) ◽  
pp. 1492-1502 ◽  
Author(s):  
John J. Clague ◽  
S. G. Evans ◽  
Iain G. Blown

A very large debris flow of unusual origin occurred in the basin of Klattasine Creek (southern Coast Mountains, British Columbia) between June 1971 and September 1973. The flow was triggered by the sudden release of up to 1.7 × 106 m3 of water from a moraine-dammed lake at the head of a tributary of Klattasine Creek. Water escaping from the lake mobilized large quantities of unconsolidated sediment in the valley below and thus produced a debris flow that travelled in one or, more likely, several surges 8 km downvalley on an average gradient of 10° to the mouth of the stream. Here, the flow deposited a sheet of coarse bouldery debris up to about 20 m thick, which temporarily blocked Homathko River. Slumps, slides, and debris avalanches occurred on the walls of the valley both during and in years following the debris flow. Several secondary debris flows of relatively small size have swept down Klattasine Creek in the 12–14 years since Klattasine Lake drained.


2006 ◽  
Vol 43 (6) ◽  
pp. 679-689 ◽  
Author(s):  
K A Simpson ◽  
M Stasiuk ◽  
K Shimamura ◽  
J J Clague ◽  
P Friele

The Mount Meager volcanic complex in southern British Columbia is snow and ice covered and has steep glaciated and unstable slopes of hydrothermally altered volcanic deposits. Three large-volume (>108 m3) volcanic debris flow deposits derived from the Mount Meager volcanic complex have been identified. The volcanic debris flows travelled at least 30 km downstream from the volcanic complex and inundated now populated areas of Pemberton Valley. Clay content and mineralogy of the deposits indicate that the volcanic debris flows were clay-rich (5%–7% clay in the matrix) and derived from hydrothermally altered volcanic material. The youngest volcanic debris flow deposit is interpreted to be associated with the last known volcanic eruption, ~2360 calendar (cal) years BP. The other two debris flows may not have been directly associated with eruptions. Volcanic debris flow hazard inundation maps have been produced using the Geographic Information System (GIS)-based modelling program, LAHARZ. The maps provide estimates of the areas that would be inundated by future moderate to large-magnitude events. Given the available data, the probability of a volcanic debris flow reaching populated areas in Pemberton Valley is ~1 in 2400 years. Additional mapping in the source regions is necessary to determine if sufficient material remains on the volcanic edifice to generate future large-magnitude, clay-rich volcanic debris flows.


1984 ◽  
Vol 21 (3) ◽  
pp. 505-517 ◽  
Author(s):  
D. C. Martin ◽  
D. R. Piteau ◽  
R. A. Pearce ◽  
P. M. Hawley

On the evening of January 23, 1982 a debris flow having an estimated volume of 11 000 m3 occurred in a stream channel on the south slope of Mount Agassiz adjacent to the Mountain Institution of the Correctional Services of Canada. The debris flow was one of many that have contributed to the formation of a large debris fan at the base of the mountain. Debris flows, large rockfalls, and other events can be expected to occur intermittently as part of the ongoing natural erosional processes in steep mountainous terrain.The paper describes the site investigation and analyses carried out and the design and construction of remedial measures to control future debris flows and rockfalls. Remedial measures consisted of improvement of stability of two large rockfall blocks in the debris flow channel using grouted dowels. In addition, two berms and a containment basin were constructed on the debris fan to control future debris flows and rockfalls. Key words: debris flows, debris fan, rockfalls, rock anchors, dowels, containment basin, deflection berm.


1996 ◽  
Vol 33 (1) ◽  
pp. 123-139 ◽  
Author(s):  
Z Y Lu ◽  
D M Cruden

The 1963 landslide on Mount Cayley, British Columbia, began at the head of Dusty Creek, a small tributary of Turbid Creek, a major creek draining Mount Cayley, and terminated at the present confluence of Dusty and Turbid creeks. About 5 × 106 m3 of partially saturated, columnar-jointed dacite and weak pyroclastic rocks moved 2.4 km downstream. The depletion zone contained three separate blocks. The landslide deposits have distinct layers that can be traced back to similar bedrock units in the undisturbed material, which are three times thicker. The accumulation zone is divided by two gullys into three blocks, which preserve, much thinned, different but overlapping portions of the volcanic stratigraphy. The 1984 rock slide on Avalache Creek, 0.8 km away, involved tuff breccia, tuff lapilli, and tuff, all easily broken. Its main track ran over thick snow and ice on the bottom of the creek. Differences in water content and displaced material led to different flow modes: the 1963 fragments formed laminar flows, which supported comparatively undeformed central plugs; the turbulent 1984 flow's deposits have no distinct layers. The two modes, laminar flow and turbulent flow, also formed different types of landslide dams. Key words: landslide, debris flow, volcano, British Columbia, tuff, lava.


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