Remedial measures for debris flows at the Agassiz Mountain Institution, British Columbia

1984 ◽  
Vol 21 (3) ◽  
pp. 505-517 ◽  
Author(s):  
D. C. Martin ◽  
D. R. Piteau ◽  
R. A. Pearce ◽  
P. M. Hawley
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Key Words ◽  
Debris Flows ◽  
Site Investigation ◽  
Remedial Measures ◽  
Stream Channel ◽  
Correctional Services ◽  
South Slope ◽  
Rock Anchors

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.

A debris flow triggered by the breaching of a moraine-dammed lake, Klattasine Creek, British Columbia

1985 ◽  
Vol 22 (10) ◽  
pp. 1492-1502 ◽  
Author(s):  
John J. Clague ◽  
S. G. Evans ◽  
Iain G. Blown
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Debris Flows ◽  
Southern Coast ◽  
Coast Mountains ◽  
Debris Avalanches ◽  
Unconsolidated Sediment ◽  
Sudden Release ◽  
Dammed Lake ◽  
Unusual Origin

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.

Evidence for catastrophic volcanic debris flows in Pemberton Valley, British Columbia

2006 ◽  
Vol 43 (6) ◽  
pp. 679-689 ◽  
Author(s):  
K A Simpson ◽  
M Stasiuk ◽  
K Shimamura ◽  
J J Clague ◽  
P Friele
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Debris Flows ◽  
Clay Content ◽  
Volcanic Complex ◽  
Large Magnitude ◽  
Volcanic Material ◽  
Inundation Maps ◽  
The Matrix ◽  
Volcanic Debris

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.

Debris flows and debris torrents in the Southern Canadian Cordillera

1985 ◽  
Vol 22 (1) ◽  
pp. 44-68 ◽  
Author(s):  
D. F. VanDine
Keyword(s):  
British Columbia ◽  
Debris Flows ◽  
Water Discharge ◽  
Warning System ◽  
Canadian Cordillera ◽  
Remedial Measures ◽  
Triggering Mechanism ◽  
Rock Fragments ◽  
Mitigation Methods ◽  
The Impact

In Canada, debris torrents (also referred to as channelized debris flows) occur in parts of British Columbia, Alberta, and the Yukon. At least 17 deaths and an estimated $100 million of damage to bridges and property can be attributed to this natural hazard. The debris mainly comprises large boulders, rock fragments, gravel- to clay-sized material, tree and wood mulch—materials that accumulate in the mountain creeks. To be susceptible to a debris torrent, a creek must have a drainage area within a critical range, a profile that is sufficiently steep, an accumulation of debris, and some form of triggering mechanism. The most common triggering mechanism is an extreme water discharge, which may result from a very intense rainfall or a temporary damming of the creek. In western Canada, the resulting torrents involve masses of debris, typically less than 50 000 m3, that travel down creeks at speeds between 3 and 12 m/s.Several passive and active forms of mitigation can be used to reduce the impact of debris torrents on creek crossings and neighbouring residents. Passive mitigation methods include avoidance of the area, relocation of structures and facilities, land use restrictions, and some form of warning system. Active mitigation methods include remedial measures to remove or counter the causes, and various forms of designed protection. Constructing check dams near the headwaters of the creek and stabilizing the valley slopes that border the creeks are examples of remedial measures. Constructing debris barriers or clear span bridges with adequate clearance are examples of designed protection.Howe Sound, north of Vancouver, British Columbia, has had a relatively high number of debris torrents. Recently, several major studies have addressed the extent of the hazard and recommended mitigative measures for this area. Many of the examples presented in this paper are drawn from this case history. Key words: debris flows, debris torrents, slope stability, Southern Canadian Cordillera, Howe Sound, geological process, design considerations.

scholarly journals Forestry on fans: a problem analysis

2003 ◽  
Vol 79 (2) ◽  
pp. 291-296 ◽  
Author(s):  
David Wilford ◽  
Matt Sakals ◽  
John Innes
Keyword(s):  
British Columbia ◽  
Adverse Effects ◽  
Key Words ◽  
Debris Flows ◽  
High Volume ◽  
Problem Analysis ◽  
Stream Channels ◽  
Forestry Practices ◽  
Forest Practices ◽  
Debris Floods

Forested fans are often crossed by roads and their high-volume stands are attractive for harvesting. Gentle slopes of fans belie the fact that hydrogeomorphic hazards can be present. Fans can be the run out zones for debris flows and they can be subject to floods and debris floods. This study assessed the effect of natural hydrogeomorphic processes on forest practices that were undertaken on 55 fans in west central British Columbia. Forest practices aggravated these processes on 41 (74%) fans, leading to increased erosion and destabilization of fan surfaces and stream channels. Identification of hydrogeomorphic hazards is needed to avoid the adverse effects of forestry practices on fans. Key words: forested fans, forestry on fans, hydrogeomorphic processes, forest practices on fans, forest practices

A catastrophic glacial outburst flood (jökulhlaup) mechanism for debris flow generation at the Spiral Tunnels, Kicking Horse River basin, British Columbia

1979 ◽  
Vol 16 (4) ◽  
pp. 806-813 ◽  
Author(s):  
Lionel E. Jackson Jr.
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
River Basin ◽  
Debris Flows ◽  
River Valley ◽  
Outburst Flood ◽  
Flow Generation

Debris flows have blocked rail and highway routes in the upper Kicking Horse River valley, British Columbia, a number of times during this century. The origins of debris flows from the most troublesome tributary basin were investigated following the debris flows and floods of September 6, 1978. A jökulhlaup (catastrophic glacial outburst flood) origin was determined for the debris flows and flood of this event. An investigation of weather records prior to debris flows of 1962, 1946, and 1925 indicates a similar origin for the 1946 and 1925 events.

Holocene debris flows and environmental history, Hazelton area, British Columbia

1991 ◽  
Vol 28 (10) ◽  
pp. 1583-1593 ◽  
Author(s):  
Allen S. Gottesfeld ◽  
Rolf W. Mathewes ◽  
Leslie M. Johnson Gottesfeld
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Oral History ◽  
Environmental History ◽  
Debris Flows ◽  
Plant Macrofossils ◽  
Sediment Layer ◽  
Catastrophic Event ◽  
Outlet Stream ◽  
History Of

Debris flow deposits of Chicago Creek and the sediment, pollen, and macrofossil records of Seeley Lake were studied to elucidate the Holocene history of the northwest flank of the Rocher Déboulé Range near Hazelton, British Columbia.The Chicago Creek drainage has experienced numerous rockfalls, debris slides, and debris flows. A large debris flow covering approximately 300 ha occurred about 3580 ± 150 BP. This flow was two to three orders of magnitude larger than historic debris flows in this drainage. It traveled about 3 km down Chicago Creek and dammed the outlet stream of Seeley Lake. A debris deposit along lower Chicago Creek is interpreted as the product of debris torrents that formed during or soon after the damming of Seeley Lake. Its surface exhibits soil development (rubification and profile development) comparable to that on the large debris flow, suggesting equivalent age.Pollen and plant macrofossils are described from a core taken in Seeley Lake. This core spans the period from ca. 9200 BP to the present. A disturbance event in 3380 ± 110 BP, correlative with the large Chicago Creek debris flow, is recorded by a clastic sediment layer and changes in the microfossil and macrofossil assemblages.The Chicago Creek debris flow and debris torrent ca. 3500 BP may be the catastrophic event recorded in the story of the Medeek, an oral history or "ada'ok" of the Gitksan people of Hazelton.

scholarly journals Case Study of the Characteristics and Dynamic Process of July 10, 2013, Catastrophic Debris Flows in Wenchuan County, China

2016 ◽  
Vol 20 (2) ◽  
pp. 1 ◽  
Author(s):  
Guisheng Hu ◽  
Ningsheng Chen ◽  
Javed Iqbal Tanoli ◽  
Yong You ◽  
Jun Li
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Large Scale ◽  
Recovery Period ◽  
Extreme Rainfall ◽  
Solid Material ◽  
Site Investigation ◽  
Dynamic Processes ◽  
Power Stations ◽  
Secondary Disasters

The Wenchuan earthquake of May 12, 2008, generated a significant amount of loose solid material that can produce devastating debris flows. In the five years since the earthquake, there have been many large-scale individual and group catastrophic debris flows that have caused lots of damage to the resettled population and the reconstruction efforts. The reconstructed towns of Yingxiu, Yinxing and Miansi have suffered debris flows and other secondary disasters in the past five years and are still not out of danger in the future. A debris-flow catastrophic event hit four towns of Wenchuan County along the Duwen Highway, part of China’s National Highway 213, at midnight on July 10, 2013, following a local extreme rainfall of 176.2mm 24h-1. The debris flows occurred simultaneously along seven gullies. A total of 15000 people were affected due to the destruction of resettlement areas, factories, power stations, and houses. Because of this devastating event, traffic along the Duwen highway was completely disrupted during the disaster and recovery period. The present study focuses on the Lianshan Bridge debris flow gully; the disaster characteristics and cause of the debris flow were analyzed based on field investigations, remote sensing interpretation, and laboratory experiments. The particular dynamic parameters of the debris flow were calculated and analyzed including density, velocity, discharge, total volume and impact force. Also, the dynamic processes and changes that occurred in the debris flow were examined, and the block and burst characteristics of debris flow were studied based on statistical calculation and analysis dynamic characteristic parameters of debris flow. Finally, a program to prevent further debris flow was proposed according to the on-site investigation and based on the analysis of the features and dynamic processes of the debris flow.  ResumenEl terremoto de Wenchuan, el 12 de mayo de 2008, generó una gran cantidad de material sólido suelto que puede producir flujos de detritos devastadores. En los años posteriores al terremoto han ocurrido deslizamientos a gran escala individuales y simultáneos que han causado daño a los habitantes reubicados y a los esfuerzos de reconstrucción. Las ciudades reconstruidas de Yingxiu, Yinxing y Miansi han sufrido flujos de detritos y otros desastres secundarios desde el terremoto, y no están exentas de eventos futuros. Un evento simultáneo de flujo de detritos afectó a cuatro localidades del condado de Wenchuan, a lo largo de la autopista de Duwen, parte de la carretera nacional 213, en la medianoche del 10 de julio de 2013, después de una lluvia extrema de 176,2 mm 24h-1. Los movimientos de detritos ocurrieron en siete pendientes. Un total de 1500 personas resultaron afectadas debido a la destrucción en áreas de reasentamiento, fábricas, estaciones eléctricas y viviendas. Debido a este devastador hecho, el tráfico de la autopista Duwen estuvo interrumpido durante el período del desastre y mientras se recuperaba la zona. Este estudio se enfoca en el deslizamiento del Puente Lianshan, donde se analizaron las características y las causas del flujo de detritos basados en investigaciones de campo, interpretación de detección remota y experimentos de laboratorio. Se calcularon y analizaron los parámetros dinámicos particulares del flujo de detritos como la densidad, velocidad, descarga, volumen total y fuerza de impacto. También se analizaron los procesos dinámicos y los cambios que ocurrieron en el flujo de detritos, al igual que se estudiaron las características de bloqueo y ruptura del flujo con base en cálculos estadísticos y análisis de los parámetros dinámicos característicos. Finalmente, se propone un programa para prevenir mayores movimientos de detritos de acuerdo con la investigación de campo y basado en los análisis de las características y procesos dinámicos del flujo de material sólido suelto.

scholarly journals Characteristics of damage to buildings by debris flows on 7 August 2010 in Zhouqu, Western China

2012 ◽  
Vol 12 (7) ◽  
pp. 2209-2217 ◽  
Author(s):  
K. H. Hu ◽  
P. Cui ◽  
J. Q. Zhang
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Structural Damage ◽  
Extreme Rainfall ◽  
Site Investigation ◽  
Gansu Province ◽  
Western China ◽  
The North ◽  
Damage Scales ◽  
The Impact

Abstract. A debris-flow catastrophe hit the city of Zhouqu, Gansu Province, western China, at midnight on 7 August 2010 following a local extreme rainfall of 77.3 mm h−1 in the Sanyanyu and Luojiayu ravines, which are located to the north of the urban area. Eight buildings damaged in the event were investigated in detail to study the characteristics and patterns of damage to buildings by debris flows. It was found that major structural damage was caused by the frontal impact of proximal debris flows, while non-structural damage was caused by lateral accumulation and abrasion of sediment. The impact had a boundary decreasing effect when debris flows encountered a series of obstacles, and the inter-positioning of buildings produced so-called back shielding effects on the damage. Impact, accumulation, and abrasion were the three main patterns of damage to buildings in this event. The damage scale depended not only on the flow properties, such as density, velocity, and depth, but also on the structural strength of buildings, material, orientation, and geometry. Reinforced concrete-framed structures can effectively resist a much higher debris-flow impact than brick-concrete structures. With respect to the two typical types of structure, a classification scheme to assess building damage is proposed by referring to the Chinese Classification System of Earthquake Damage to Buildings. Furthermore, three damage scales (major structural, minor structural, and non-structural damage) are defined by critical values of impact pressure. Finally, five countermeasures for effectively mitigating the damage are proposed according to the on-site investigation.

scholarly journals The mechanism of landslide-induced debris flow in Geothermal area, Bukit Barisan Mountains of Sumatra, Indonesia

2021 ◽  
Author(s):  
Wahyu Wilopo ◽  
Teuku Faisal Fathani
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Volcanic Rocks ◽  
Thick Layer ◽  
Source Area ◽  
Site Investigation ◽  
Xrd Analysis ◽  
Alluvial Fan ◽  
Mountain Range ◽  
Geothermal Area

Landslides frequently occur in Indonesia, especially in the geothermal areas located on Sumatra's mountainous island. On April 28, 2016, around 04:30 Western Indonesia Time, a landslide-induced debris flow occurred in Lebong District, Bengkulu Province, Indonesia. The source area of the landslide was located at Beriti Hill on the Bukit Barisan Mountain Range. It resulted in 6 fatalities and damage to infrastructures such as geothermal facilities, roads, water pipes, houses, and bridges. Subsequent landslides and debris flows occurred on April 30, May 2, and 3, 2016. Therefore, this study aims to examine the mechanism and to know the most significant contributing factor to the Beriti Hill landslide. Site investigation, soil sampling, XRD analysis, and Lidar analysis were carried out in the research. Beriti Hill is a geothermal area with many manifestations and is composed of volcanic rocks. Alteration processes produced a thick layer of soil from volcanic rocks. The thick soil dominated by clay minerals and steep slopes is the dominant controlling factor of a landslide, triggered by high rainfall intensity. Debris flows are recurring events based on the Air Kotok river's stratigraphic data downstream of the landslide area. The debris flow material is toxic due to the low pH from the geothermal process. Therefore, the alluvial fan deposit area from Beriti Hill debris flow is a hazard zone and unsuitable for settlement and agriculture.

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