Meteorological antecedents to debris flow in southwestern British Columbia; Some case studies

Author(s):  
Michael Church ◽  
Michael J. Miles
2021 ◽  
Author(s):  
Nicholas Scott

This article explores how longer distance cycling can advance interspecies mobility justice, a theory of (im)mobilities and justice that includes other-than-human persons and habitats as worthy of our positive moral obligations. I argue that longer distance cycling can advance interspecies mobility justice by promoting socially inclusive and ecologically good cycling practices that redress the active travel poverty of marginalized and colonized populations, while replacing rather than augmenting auto roads with active travel routes that help humans respect other species. The article theorizes longer distance cycling not as some specific number of kilometres, but rather as the social production of cycling space across gentrified central cities, struggling inner suburbs, outer exurbs and rural countrysides. To explore this argument my analysis focuses on Canada, an extreme context for longer distance cycling. I offer a comparison of two case studies, situated on the country’s west and east coasts, Vancouver, British Columbia and Halifax, Nova Scotia, drawing on an ongoing ethnographic study of cycling practices and politics in Canada.  


2014 ◽  
Vol 2 (1) ◽  
pp. 315-346
Author(s):  
J.-C. Chen ◽  
M.-R. Chuang

Abstract. Three debris-flow gullies, the Hong-Shui-Xian, Sha-Xin-Kai, and the Xin-Kai-Dafo gullies, located in the Shinfa area of southern Taiwan were selected as case studies of the discharge of landslide-induced debris flows caused by Typhoon Morakot in 2009. The inundation characteristics of the three debris flows, such as the debris-flow volume, the deposition area, maximum flow depth, and deposition depth, were collected by field investigations and simulated using the numerical modeling software FLO-2D. The discharge coefficient cb, defined as the ratio of the debris-flow discharge Qdp to the water-flow discharge Qwp, was proposed to determine Qdp, and Qwp was estimated by a rational equation. Then, cb was calibrated by a comparison between the field investigation and the numerical simulation of the inundation characteristics of debris flows. Our results showed that the values of cb range from 6 to 18, and their values are affected by the landslide ratio The empirical relationships between Qdp and Qwp were also presented.


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.


Sign in / Sign up

Export Citation Format

Share Document