scholarly journals Definitions and Concepts for Quantitative Rockfall Hazard and Risk Analysis

2021 ◽  
Author(s):  
Didier Hantz ◽  
Jordi Corominas ◽  
Giovanni B. Crosta ◽  
Michel Jaboyedoff
Keyword(s):  
At Risk ◽  
Failure Probability ◽  
Rockfall Hazard ◽  
Failure Frequency ◽  
Process Failure ◽  
Failure Propagation ◽  
Element At Risk ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment ◽  
Definition Of

There is an increasing need for quantitative rockfall hazard and risk assessment that requires a precise definition of the terms and concepts used for this particular type of landslide. This paper suggests to use terms that appear to be the more logic and explicit as possible, and describes methods to derive some of the main hazard and risk descriptors. The terms and concepts presented concern the rockfall process (failure, propagation, fragmentation, modelling) and the hazard and risk descriptors, distinguishing the cases of localized hazards and diffused hazards. For a localized hazard, the failure probability of the considered rock compartment in a given period of time has to be assessed and the probability for a given element at risk to be impacted with a given energy must be derived combining the failure probability, the propagation probability and the exposure of the element. For a diffuse hazard that is characterized by a failure frequency, the number of rockfalls reaching the element at risk per unit of time and with a given energy (reach frequency) can be derived. However, when the element at risk is not replaced or repaired, the probability that it is impacted by at least one rockfall must be considered.

scholarly journals Definitions and Concepts for Quantitative Rockfall Hazard and Risk Analysis

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 158
Author(s):  
Didier Hantz ◽  
Jordi Corominas ◽  
Giovanni B. Crosta ◽  
Michel Jaboyedoff
Keyword(s):  
Risk Assessment ◽  
At Risk ◽  
Failure Probability ◽  
Rockfall Hazard ◽  
Process Failure ◽  
Failure Propagation ◽  
Element At Risk ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment ◽  
Definition Of

There is an increasing need for quantitative rockfall hazard and risk assessment that requires a precise definition of the terms and concepts used for this particular type of landslide. This paper suggests using terms that appear to be the most logic and explicit as possible and describes methods to derive some of the main hazards and risk descriptors. The terms and concepts presented concern the rockfall process (failure, propagation, fragmentation, modelling) and the hazard and risk descriptors, distinguishing the cases of localized and diffuse hazards. For a localized hazard, the failure probability of the considered rock compartment in a given period of time has to be assessed, and the probability for a given element at risk to be impacted with a given energy must be derived combining the failure probability, the reach probability, and the exposure of the element. For a diffuse hazard that is characterized by a failure frequency, the number of rockfalls reaching the element at risk per unit of time and with a given energy (passage frequency) can be derived. This frequency is relevant for risk assessment when the element at risk can be damaged several times. If it is not replaced, the probability that it is impacted by at least one rockfall is more relevant.

scholarly journals Rockfall hazard and risk assessment: an example from a high promontory at the historical site of Monemvasia, Greece

2012 ◽  
Vol 12 (6) ◽  
pp. 1823-1836 ◽  
Author(s):  
H. Saroglou ◽  
V. Marinos ◽  
P. Marinos ◽  
G. Tsiambaos
Keyword(s):  
Fall Risk ◽  
Rating System ◽  
Protection Measures ◽  
Rockfall Hazard ◽  
The Past ◽  
Toppling Failure ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment ◽  
The Town ◽  
Southern Greece

Abstract. The paper presents the kinematics of rock instability of a high limestone promontory, where the Monemvasia historical site is situated, in Peloponnese in Southern Greece. The instability phenomena poses a significant threat to the town located at the base of the slope. Rockfall episodes occurred in the past due to the relaxation of the high cliff, whereas significant undermining of the castle frontiers has been observed at the slope crest. The predominant types of instability are of planar, wedge and toppling failure of medium to large blocks. In order to investigate the existing stability conditions and decide upon the protection measures, stability and rockfall analyses were carried out for numerous slope sections under different loading conditions and protection measures were suggested. A rock-fall risk rating system is proposed, which is based on morphological and structural criteria of the rock mass and on vulnerability and consequences. The rating system is applied for individual sections along the slope and a risk map was produced, which depicted areas having different degree of risk against rockfall occurrences.

scholarly journals EXTRACTION OF ELEMENT AT RISK FOR LANDSLIDES USING REMOTE SENSING METHOD

2018 ◽  
Vol XLII-4/W9 ◽  
pp. 181-188
Author(s):  
R. C. Hasan ◽  
Q. A. Rosle ◽  
M. A. Asmadi ◽  
N. A. Mohd Kamal
Keyword(s):  
At Risk ◽  
Extraction Process ◽  
Automatic Process ◽  
Landslide Risk ◽  
Lidar Data ◽  
Large Area ◽  
Building Footprint ◽  
Element At Risk ◽  
Hazard And Risk ◽  
Study Sites

<p><strong>Abstract.</strong> One of the most critical steps towards landslide risk analysis is the determination of element at risk. Element at risk describes any object that could potentially fail or exposed to hazards during disaster. Without quantification of element at risk information, it is difficult to estimate risk. This paper aims at developing a methodology to extract and quantity element at risk from airborne Light Detection and Ranging (LiDAR) data. The element at risk map produced was then used to construct exposure map which describes the amount of hazard for each element at risk involved. This study presented two study sites at Kundasang and Kota Kinabalu in Sabah with both areas have experienced major earthquake in June 2015. The results show that not all the features can be automatically extracted from the LiDAR data. For example, automatic extraction process could be done for building footprint and building heights, but for others such as roads and vegetation areas, a manual digitization is still needed because of the difficulties to differentiate between these features. In addition to this, there were also difficulties in identifying attribute for each feature, for example to separate between federal roads with state and unpaved roads. Therefore, for large area hazard and risk mapping, the authors suggested that an automatic process should be investigated in the future to reduce time and cost to extract important features from LiDAR data.</p>

scholarly journals Rockfall hazard and risk assessment on forested slopes, examples from Czechia

Geografie ◽  
2011 ◽  
Vol 116 (2) ◽  
pp. 144-155 ◽  
Author(s):  
Jan Klimeš
Keyword(s):  
Risk Assessment ◽  
Quantitative Risk Assessment ◽  
Forest Composition ◽  
Protective Function ◽  
One Dimensional ◽  
Rockfall Hazard ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment ◽  
The Village ◽  
Forest Conditions

Rockfall hazard is assessed using Rockfor.net, which is one dimensional tool for assessing the protective function of forests against rockfall. Three sites where chosen to test the tool with different morphological and forest conditions. For each site, it was evaluated how the boulder size and forest composition affects the probability of the rocks to surpass the forested slope. The Rockfor.net was also used for back calculations of past event, which happened during the floods in July 1997 in the village of Bystřička in the Vsetínské vrchy Hills. In this case, also a partial quantitative risk assessment with suggestions for risk management was performed.

scholarly journals Rockfall hazard and risk assessment of road slopes.

2013 ◽  
Vol 47 (4) ◽  
pp. 1664 ◽  
Author(s):  
A. Andrianopoulos ◽  
H. Saroglou ◽  
G. Tsiambaos
Keyword(s):  
Risk Assessment ◽  
Hazard Assessment ◽  
Weather Conditions ◽  
Quantitative Risk Assessment ◽  
Rockfall Hazard ◽  
Traffic Conditions ◽  
Hazard And Risk ◽  
Trajectory Models ◽  
Hazard And Risk Assessment ◽  
National Road

This paper presents and compares the main methods of hazard and risk assessment for road slopes. Hazard assessment is achieved by rating several parameters such as the slope’s geometry, traffic conditions, the geology and the rockmass properties, weather conditions, historical rockfall data etc. A hazard assessment can also be executed using 2D or 3D trajectory models, by combining the frequency of a rockfall and the kinetic energy of a falling rock. Several methodologies have been developed for risk assessment, varying from simplistic approaches to comprehensive probabilistic or quantitative risk assessment methods. Finally, the most suitable methods were used in order to assess the level of hazard and risk as an example (the data from two sections of the national road at Tempi Gorge, Greece) where many rockfall events occurred in the past few years.

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