An assessment procedure for glacial hazards in the Swiss Alps

2004 ◽  
Vol 41 (6) ◽  
pp. 1068-1083 ◽  
Author(s):  
Christian Huggel ◽  
Wilfried Haeberli ◽  
Andreas Kääb ◽  
Daniel Bieri ◽  
Shaun Richardson
Keyword(s):  
Debris Flow ◽  
Low Frequency ◽  
Swiss Alps ◽  
Assessment Procedure ◽  
Mountain Regions ◽  
Probability Of Occurrence ◽  
Mountain Environments ◽  
Assessment Procedures ◽  
Ice Avalanche ◽  
Glacial Hazards

Glacial hazards such as ice avalanches, glacial lake outburst floods, and debris flows have caused severe damage in populated mountain regions such as the Swiss Alps. Assessment of such hazards must consider basic glaciological, geomorphological, and hydraulic principles together with experience gained from previous events. An approach is presented here to assess the maximum event magnitude and probability of occurrence of glacial hazards. Analysis of magnitude is based on empirical relationships derived from published case histories from the Swiss Alps and other mountain regions. Probability of occurrence is difficult to estimate because of rapid changes in the nature of glacial systems, the low frequency of events, and the high complexity of the involved processes. Here, the probability is specified in qualitative and systematic terms based on indicators such as dam type, geometry, and freeboard height (for glacial lakes) and tendency of avalanche repetition, precursor events, and increased water supply to the glacier bed (for ice avalanche events). The assessment procedures are applied to a recent lake outburst with subsequent debris flow and to an ice avalanche in the Swiss Alps. The results yield reasonable event maxima that were not exceeded by actual events. The methods provide first-order assessments and may be applied in dynamic mountain environments where population and infrastructure growth require continuous evaluation of hazards.Key words: glacial hazards, lake outburst, debris flow, ice avalanche, hazard assessment procedure, probability of occurrence.

BS 7910: History and Future Developments

2009 ◽  
Author(s):  
Isabel Hadley
Keyword(s):  
Assessment Methods ◽  
Weld Strength ◽  
Assessment Procedure ◽  
Metallic Structures ◽  
History Of ◽  
Fracture Assessment ◽  
Offshore Industry ◽  
Crack Tip Constraint ◽  
The Uk ◽  
Assessment Procedures

BS 7910, the UK procedure for the assessment of flaws in metallic structures, was first published almost 30 years ago in the form of a fracture/fatigue assessment procedure, PD6493. It provided the basis for analysing fabrication flaws and the need for repair in a rational fashion, rather than relying on long-established (and essentially arbitrary) workmanship rules. The UK offshore industry in particular embraced this new approach to flaw assessment, which is now widely recognised by safety authorities and specifically referred to in certain design codes, including codes for pressure equipment. Since its first publication in 1980, PD6493/BS 7910 has been regularly maintained and expanded, taking in elements of other publications such as the UK power industry’s fracture assessment procedure R6 (in particular the Failure Assessment Diagram approach), the creep assessment procedure PD6539 and the gas transmission industry’s approach to assessment of locally thinned areas in pipelines. The FITNET European thematic network, run between 2002 and 2006, has further advanced the state of the art, bringing in assessment methods from SINTAP (an earlier European research project), R6, R5 and elsewhere. In particular, the FITNET fracture assessment methods represent considerable advances over the current BS 7910 methods; for example, weld strength mismatch can be explicitly analysed by using FITNET Option 2, and crack tip constraint through Option 5. Corrosion assessment methods in FITNET are also more versatile than those of BS 7910, and now include methods for vessels and elbows as well as for pipelines. In view of these recent advances, the BS 7910 committee has decided to incorporate many elements of the FITNET procedure into the next edition of BS 7910, to be published c2012. This paper summarises the history of the development of BS 7910, its relationship with other flaw assessment procedures (in particular FITNET and R6) and its future.

scholarly journals The importance of entrainment and bulking on debris flow runout modeling: examples from the Swiss Alps

2015 ◽  
Vol 15 (11) ◽  
pp. 2569-2583 ◽  
Author(s):  
F. Frank ◽  
B. W. McArdell ◽  
C. Huggel ◽  
A. Vieli
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Field Data ◽  
Average Rate ◽  
Hazard Analysis ◽  
Maximum Shear Stress ◽  
Empirical Relationship ◽  
Swiss Alps ◽  
Field Site ◽  
Practical Applications

Abstract. This study describes an investigation of channel-bed entrainment of sediment by debris flows. An entrainment model, developed using field data from debris flows at the Illgraben catchment, Switzerland, was incorporated into the existing RAMMS debris-flow model, which solves the 2-D shallow-water equations for granular flows. In the entrainment model, an empirical relationship between maximum shear stress and measured erosion is used to determine the maximum potential erosion depth. Additionally, the average rate of erosion, measured at the same field site, is used to constrain the erosion rate. The model predicts plausible erosion values in comparison with field data from highly erosive debris flow events at the Spreitgraben torrent channel, Switzerland in 2010, without any adjustment to the coefficients in the entrainment model. We find that by including bulking due to entrainment (e.g., by channel erosion) in runout models a more realistic flow pattern is produced than in simulations where entrainment is not included. In detail, simulations without entrainment show more lateral outflow from the channel where it has not been observed in the field. Therefore the entrainment model may be especially useful for practical applications such as hazard analysis and mapping, as well as scientific case studies of erosive debris flows.

scholarly journals Enhancing learning potential score in EFL listening comprehension and self-regulation through self-regulated dynamic assessment procedures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Parisa Abdolrezapour ◽  
Nasim Ghanbari
Keyword(s):  
Listening Comprehension ◽  
Comparison Group ◽  
Dynamic Assessment ◽  
Self Regulation ◽  
Control Group ◽  
Assessment Procedure ◽  
Learning Potential ◽  
Theoretical Understanding ◽  
Efl Learners ◽  
Assessment Procedures

AbstractThis study aimed to integrate self-regulation strategies into dynamic assessment procedures of listening comprehension in an EFL setting and examine the possibility of raising EFL students’ listening comprehension and self-regulation skills. In addition, it explored the possibility of enhancing EFL learners’ potential scores in listening comprehension and self-regulation through applying self-regulation activities as a tool for motivating learners while being assessed. The assessment procedure was based on Vygotsky’s notion of the zone of proximal development and self-regulated intervention. The participants were 49 Iranian EFL learners in three groups: a control group, which received the institute’s regular instructional activities; a comparison group, which received dynamic assessment (DA); and an experimental group which received self-regulated dynamic assessment (SR-DA) procedures, in the form of an intervention focusing on cognitive, emotional, and behavioral self-regulation states of learners. Results of the study pointed to the potential of SR-DA for enhancing the students’ learning potential over and beyond that which is available from the DA (as offered to the comparison group) and the static testing (as offered to the control group). The results have important implications for a theoretical understanding of the mechanisms through which EFL learners develop necessary self-regulation skills in the EFL context.

scholarly journals Locally Developed Oral Skills Evaluation in ESL/EFL Classrooms: A Checklist for Developing Meaningful Assessment Procedures

2003 ◽  
Vol 21 (1) ◽  
pp. 79 ◽  
Author(s):  
David N. Ishii ◽  
Kyoko Baba
Keyword(s):  
Contextual Factors ◽  
Assessment Process ◽  
Assessment Procedure ◽  
Learner Performance ◽  
Course Objectives ◽  
Efl Teachers ◽  
Efl Classrooms ◽  
Assessment Procedures ◽  
Oral Skills ◽  
The Impact

This article explores how teachers, students and other stakeholders collaboratively develop classroom-based assessment procedures for the evaluation of oral skills. By considering crucial issues in assessment such as validity, teacher-learner collaboration, and contextual factors, the authors provide a checklist that will help ESL/EFL teachers develop meaningful assessment procedures for their own classrooms. The checklist addresses 16 questions worth considering in five test-developing stages: (a) identification of course objectives; (b) identification of skills, strategies, tasks and content; (c) design of rating procedures; (d) interpretation of learner performance; and (e) reflection on the impact of the assessment procedure. In all the stages the authors emphasize the significance of involving students in the assessment process, which promotes students' responsibility for their own learning.

Debris flow hazards for mountain regions of Russia: regional features and key events

2017 ◽  
Vol 88 (S1) ◽  
pp. 199-235 ◽  
Author(s):  
Veniamin Perov ◽  
Sergey Chernomorets ◽  
Olga Budarina ◽  
Elena Savernyuk ◽  
Tatiana Leontyeva
Keyword(s):  
Debris Flow ◽  
Mountain Regions ◽  
Regional Features ◽  
Key Events ◽  
Regions Of Russia

Helicopter-borne ground-penetrating radar investigations on temperate alpine glaciers: A comparison of different systems and their abilities for bedrock mapping

Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. WA119-WA129 ◽  
Author(s):  
Anja Rutishauser ◽  
Hansruedi Maurer ◽  
Andreas Bauder
Keyword(s):  
Ground Penetrating Radar ◽  
Low Frequency ◽  
Large Data ◽  
Internal Reflection ◽  
Swiss Alps ◽  
Reflection Band ◽  
Data Set ◽  
Investigation Area ◽  
Attractive Option ◽  
Ground Penetrating

On the basis of a large data set, comprising approximately 1200 km of profile lines acquired with different helicopter-borne ground-penetrating radar (GPR) systems over temperate glaciers in the western Swiss Alps, we have analyzed the possibilities and limitations of using helicopter-borne GPR surveying to map the ice-bedrock interface. We have considered data from three different acquisition systems including (1) a low-frequency pulsed system hanging below the helicopter (BGR), (2) a stepped frequency system hanging below the helicopter (Radar Systemtechnik GmbH [RST]), and (3) a commercial system mounted directly on the helicopter skids (Geophysical Survey Systems Incorporated [GSSI]). The systems showed considerable differences in their performance. The best results were achieved with the BGR system. On average, the RST and GSSI systems yielded comparable results, but we observed significant site-specific differences. A comparison with ground-based GPR data found that the quality of helicopter-borne data is inferior, but the compelling advantages of airborne surveying still make helicopter-borne data acquisition an attractive option. Statistical analyses concerning the bedrock detectability revealed not only large differences between the different acquisition systems but also between different regions within our investigation area. The percentage of bedrock reflections identified (with respect to the overall profile length within a particular region) varied from 11.7% to 68.9%. Obvious factors for missing the bedrock reflections included large bedrock depths and steeply dipping bedrock interfaces, but we also observed that internal features within the ice body may obscure bedrock reflections. In particular, we identified a conspicuous “internal reflection band” in many profiles acquired with the GSSI system. We attribute this feature to abrupt changes of the water content within the ice, but more research is required for a better understanding of the nature of this internal reflection band.

Defect Assessment Procedure for Low to High Temperature Range

2003 ◽  
Author(s):  
Bilal Dogan ◽  
Robert Ainsworth
Keyword(s):  
High Temperature ◽  
Growth Conditions ◽  
Life Assessment ◽  
Assessment Procedure ◽  
High Temperature Range ◽  
Temperature Range ◽  
Defect Assessment ◽  
Creep Fatigue ◽  
Recent Developments ◽  
Assessment Procedures

There are many similarities between available procedures used for defect assessment. They have been developed as a result of experience gained from material-specific programs and have often been verified using the same data. One recently updated document covering life assessment procedures under creep and creep/fatigue crack growth conditions is BS 7910. This document takes into account some of the most recent developments in the subject, including some from the British Energy R5 Procedure. Future developments in defect assessment procedures will follow the route of simplified and unified codes covering defect behaviour in the low to high temperature range. In this paper, the relevance of the insignificant creep curves in RCC-MR for defect free structures and the creep exemption criteria in BS7910 are examined. Then, an overview is given of some European developments in defect assessment methods for Fitness-for-Service assessment, based on recent and current projects such as the EC thematic network FITNET.

Changing debris flow activity after sudden sediment input: a case study from the Swiss Alps

Geology Today ◽  
2017 ◽  
Vol 33 (6) ◽  
pp. 216-223 ◽  
Author(s):  
Patrick Baer ◽  
Christian Huggel ◽  
Brian W. McArdell ◽  
Florian Frank
Keyword(s):  
Debris Flow ◽  
Swiss Alps ◽  
Sediment Input ◽  
Flow Activity

Wavelet Method to Extract Shock Signal of Debris Flow

2011 ◽  
Vol 199-200 ◽  
pp. 958-965
Author(s):  
Hong Kai Chen ◽  
Hong Mei Tang ◽  
Yu Ping Zhang ◽  
Xiao Ying He
Keyword(s):  
Debris Flow ◽  
Energy Distribution ◽  
Model Experiment ◽  
Low Frequency ◽  
Wavelet Method ◽  
Design Load ◽  
Shock Energy ◽  
Initial Shock ◽  
Debris Flow Disaster

The shock signal’s fluctuation characteristics of debris flow stem from two aspects, one is the composition of debris flow with the solid and the liquid, another is the surging property of debris flow in motion. Based on the initial shock signals collected in model experiment in laboratory, 9 shock spectrum levels are decomposed by the db8 wavelet method, i.e., 0~0.195Hz, 0.195~ 0.391Hz, 0.391~0.781Hz, 0.781~1.5625Hz, 1.563~3.125Hz, 3.125~ 6.25Hz, 6.25~12.5 Hz, 12.5~25Hz, and 25~50Hz. Taking the peak each shock spectrum as the standard, the energy distribution curves of 9 shock spectrum levels are obtained. These curves display that the shock energy of debris flow focus on the low frequency smaller than 1.0Hz, and the percentage below 6.25Hz is about 95%. The results provide a reference to select wallop peak as the design load of structures against debris flow disaster.

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