A two-stage probabilistic approach for the risk assessment of submarine landslides induced by gas hydrate exploitation

2020 ◽  
Vol 99 ◽  
pp. 102158
Author(s):  
Yangming Chen ◽  
Lulu Zhang ◽  
Chencong Liao ◽  
Mingjing Jiang ◽  
Ming Peng
Keyword(s):  
Risk Assessment ◽  
Gas Hydrate ◽  
Probabilistic Approach ◽  
Submarine Landslides ◽  
Two Stage

scholarly journals Assessing the Risk of Contaminant Dispersion From Fibrous Sediments of Industrial Origin

2021 ◽  
Vol 8 ◽  
Author(s):  
Gunnel Göransson ◽  
Anna Apler ◽  
Anna-Karin Dahlberg ◽  
Hjördis Löfroth ◽  
Sarah Josefsson ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Wind Waves ◽  
Probabilistic Approach ◽  
Fluid Flows ◽  
Chemical Diffusion ◽  
Threshold Level ◽  
Strong Wind ◽  
Submarine Landslides ◽  
Time Duration

Unregulated discharges of wastewater from pulp and paper factories resulted in the formation of relatively thick organic (cellulose) rich sediments in shallow waters along the Swedish coast. These deposits are known as fiberbanks and are contaminated by persistent organic pollutants (POPs), metals and methylmercury, which can be dispersed by diffusion and advective processes coupled to propeller wash, high river discharges, strong wind waves and submarine landslides. Based on a case study of polychlorinated biphenyls (PCBs), one group of prevalent POPs in the fiberbanks, we present a probabilistic approach to estimate the potential risk of dispersion of fiberbank contaminants. The approach allows for estimation of the dispersal pathways that dominates the risk within a given time and provides more insight about the significance of various dispersion processes. We show that it is highly likely that chemical diffusion and advection triggered by ship-induced resuspension will disperse PCBs (sum of seven congeners; Σ7PCB) above a threshold level for environmental impact, while the likelihood of river and wind-wave generated resuspension dispersion pathways are lower (∼20%, respectively). We further show that there is approximately 5% likelihood that a submarine landslide will disperse Σ7PCB above the threshold level. The study implies that the governing parameters for risk assessment specifically should include reliable data on contaminant concentration, water depth above the fiberbank, estimation of concerned fiberbank areas, time duration of erosive fluid flows and measured diffusion. The approach provides insight into the importance of various dispersion processes. We suggest that it can be applied to support risk assessment, especially when there are limited available data and/or knowledge about the system under study.

Risk assessment of white phosphorus in military training areas, a probabilistic approach

2006 ◽  
Vol 164 ◽  
pp. S139-S140 ◽  
Author(s):  
Øyvind Albert Voie ◽  
Kjetil S. Longva ◽  
Arnljot E. Strømseng ◽  
Arnt Johnsen
Keyword(s):  
Risk Assessment ◽  
Military Training ◽  
Probabilistic Approach ◽  
White Phosphorus ◽  
Military Training Areas

scholarly journals Development of a Bayesian network for probabilistic risk assessment of pesticides

2021 ◽  
Author(s):  
Sophie Mentzel ◽  
Merete Grung ◽  
Knut Erik Tollefsen ◽  
Marianne Stenrod ◽  
Karina Petersen ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Bayesian Network ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Probabilistic Risk Assessment ◽  
Risk Calculation ◽  
Link Information ◽  
Probabilistic Risk

Conventional environmental risk assessment of chemicals is based on a calculated risk quotient, representing the ratio of exposure to effects of the chemical, in combination with assessment factors to account for uncertainty. Probabilistic risk assessment approaches can offer more transparency, by using probability distributions for exposure and/or effects to account for variability and uncertainty. In this study, a probabilistic approach using Bayesian network (BN) modelling is explored as an alternative to traditional risk calculation. BNs can serve as meta-models that link information from several sources and offer a transparent way of incorporating the required characterization of uncertainty for environmental risk assessment. To this end, a BN has been developed and parameterised for the pesticides azoxystrobin, metribuzin, and imidacloprid. We illustrate the development from deterministic (traditional) risk calculation, via intermediate versions, to fully probabilistic risk characterisation using azoxystrobin as an example. We also demonstrate seasonal risk calculation for the three pesticides.

Susceptibility assessment of gas hydrate dissociation occurrence along European continental margins and adjacent areas. GARAH project (GeoERA)

2021 ◽  
Author(s):  
Ricardo León ◽  
Christopher Rochelle ◽  
André Burnol ◽  
Carmen Julia Giménez- Moreno ◽  
Tove Nielsen ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Gas Hydrate ◽  
Control Factor ◽  
Continental Margins ◽  
Baseline Scenario ◽  
Submarine Landslides ◽  
Susceptibility Assessment ◽  
Map Algebra ◽  
Hydrate Dissociation ◽  
Density Map

<p>The Pan-European gas-hydrate relate GIS database of GARAH project has allowed assessing the susceptibility of seafloor areas affected by hydrate dissociation. This study has been applied as a first step for the hydrate related risk assessment along the European continental margins. Several factors and variables have been taken into account. They have been defined by their relationship with the presence of hydrates below seafloor and weighted depending on the confidence of finding hydrates in this site. The maximum weight (or confidence) has been given to the recovered samples of gas hydrates or hydrate-dissociation evidences such as degassing or liquation structures observed in gravity cores. Seismic indicators of the presence of gas hydrate or hydrocarbon seabed fluid flow such as BSR, blanking acoustic, amplitude anomalies or the presence of geological structures of seabed fluid flow in the neighbouring of the GHSZ have been weighted with a lower value. The theoretical gas hydrate stability zone (GHSZ) for a standard composition for biogenic gas has been taken into account as another control factor and constrain feature. Seafloor areas out of the theoretical GSHZ have been excluded as potential likelihood to be affected by hydrate dissociation processes. The base of GHSZ has been classified as a critical area for these dissociation processes.</p><p>The proposed methodology analyses the geological hazard by means of the susceptibility assessment, defined by the likelihood of occurrence of hydrate dissociation, collapses, crater-like depressions or submarine landslides over seafloor. The baseline scenario is that gas hydrate occurrence is only possible in seafloor areas where pressure (bathymetry) and seafloor temperature conditions are inside the theoretical GHSZ. Inside GHSZ, the occurrence of gas hydrate is directly related to the presence of its evidences (direct samples of hydrates) or indicators (eg. pore water and velocity anomalies, BSR, gas chimneys, among others), as well as the occurrence of hydrocarbon fluid flow structures inside GHSZ. Finally, the likelihood of the seafloor to be affect gas hydrate dissociation processes will be major at the base of the GHSZ and in the neighbouring of the gas hydrate evidences and indicators. In order to proof this initial hypothesis, a susceptibility assessment has been carried out throughout map algebra in a GIS environment from a density map of evidences and indicators and the Pan-European map of the GHSZ over seafloor. Specifically, it has been conceived as a segmentation in three levels by quantiles resulting of the addition of the density map of evidences and indicators and the weighted map of the GHSZ over seafloor.</p><p> </p><p><strong>Acknowledgment</strong></p><p>GARAH project. GeoERA - GeoE.171.002</p>

Design and Test of a MEMS Accelerometer Array for Submarine Landslide Displacement Monitoring

2021 ◽  
Vol 55 (1) ◽  
pp. 5-16
Author(s):  
Yongqiang Ge ◽  
Jiawang Chen ◽  
Chen Cao ◽  
Jiamin He ◽  
Yan Sheng ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Integrated Circuit ◽  
Slope Failure ◽  
Circuit Board ◽  
Measurement Unit ◽  
Physical Model Test ◽  
Submarine Landslides ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
The Difference

AbstractSubmarine landslides in gas hydrate areas are a significant geo-hazard that can cause considerable damage. The processes and mechanism of submarine landslides caused by gas hydrate dissociation are not clearly understood. Therefore, we designed a micro-electro-mechanical systems (MEMS) accelerometer array to study and monitor the deep displacement of submarine landslides. The MEMS accelerometer array consists of several gravity acceleration-sensing units that are protected and positioned using a flexible circuit board and elastic steel tape, such that all the units are connected to an Inter-Integrated Circuit (IIC) communication bus. By sensing the three-axis tilt angles, the direction and magnitude of the displacement for a measurement unit can be calculated; then, the overall displacement of the array is calculated as the difference in the displacements from the initial values. To ensure the accuracy of the tilt angle and displacement calculation, the calibration and verification test of the single MEMS sensor and sensor array is conducted. The MEMS accelerometer array is verified with respect to its principle and arrangement by a laboratory physical model test, and the initial experimentation demonstrated the capacities of the monitoring system for collecting real-time and in-situ information about the dynamic process and propagation of slope failure.

scholarly journals CLIMADA – a global weather and climate risk assessment platform

2019 ◽  
Author(s):  
Gabriela Aznar-Siguan ◽  
David N. Bresch
Keyword(s):  
Risk Assessment ◽  
Probabilistic Approach ◽  
Extreme Weather Events ◽  
Climate Conditions ◽  
Hazard Exposure ◽  
Weather Events ◽  
Wide Range ◽  
High Population Growth ◽  
Socio Economic Impact ◽  
Event Based

Abstract. The need for assessing the risk of extreme weather events is ever increasing. In addition to quantification of risk today, the role of aggravating factors such as high population growth and changing climate conditions do matter, too. We present the open source software CLIMADA, which integrates hazard, exposure and vulnerability to compute the necessary metrics to assess risk and to quantify socio-economic impact. The software design is modular and object-oriented, offering a simple collaborative framework and a parallelization strategy which allows for scalable computations on clusters. CLIMADA supports multi-hazard calculations and provides an event-based probabilistic approach that is globally consistent for a wide range of resolutions, suitable for whole-country to detailed local studies. This paper uses the platform to estimate and contextualize the damage of hurricane Irma in the Caribbean in 2017. Most of the affected islands are non-sovereign countries and do also rely on overseas support in case disaster strikes. The risk assessment performed for this region, based on remotely available data available shortly before or hours after landfall of Irma, proves to be close to reported damage and hence demonstrates a method to provide readily available impact estimates and associated uncertainties in real time.

Sign in / Sign up

Export Citation Format

Share Document