Hazard Assessment Methodology Research Articles

Rainfall event-based landslide susceptibility zonation mapping

Landslide susceptibility assessment is a major research topic in geo-disaster management. In recent days, various landslide susceptibility and landslide hazard assessment methodologies have been introduced with diverse thoughts of assessment and validation method. Fundamentally, in landslide susceptibility zonation mapping, the susceptibility predictions are generally made in terms of likelihoods and probabilities. An overview of landslide susceptibility zoning practices in the last few years reveals that susceptibility maps have been prepared to have different accuracies and reliabilities. To address this issue, the work in this paper focuses on extreme event-based landslide susceptibility zonation mapping and its evaluation. An ideal terrain of northern Shikoku, Japan, was selected in this study for modeling and event-based landslide susceptibility mapping. Both bivariate and multivariate approaches were considered for the zonation mapping. Two event-based landslide databases were used for the susceptibility analysis, while a relatively new third event landslide database was used in validation. Different event-based susceptibility zonation maps were merged and rectified to prepare a final susceptibility zonation map, which was found to have an accuracy of more than 77 %. The multivariate approach was ascertained to yield a better prediction rate. From this study, it is understood that rectification of susceptibility zonation map is appropriate and reliable when multiple event-based landslide database is available for the same area. The analytical results lead to a significant understanding of improvement in bivariate and multivariate approaches as well as the success rate and prediction rate of the susceptibility maps.

Probabilistic landslide hazard assessment using Copula modeling technique

A new probabilistic methodology for landslide hazard assessment in regional scale using Copula modeling technique is presented. The current probabilistic landslide hazard analyses are performed under the assumption that landslide hazard elements, such as magnitude, frequency, and location, are independent. In this paper, a general approach is proposed to consider the possible dependence among hazard elements. Part of the Seattle, WA area was selected to evaluate the competence of the presented method. A total of 357 slope failure events and their corresponding topography and geology data were included in the study to develop and test the model. Based on the results, the mean success rates of the presented model in predicting landslide occurrence are 90 % in hazardous area and 12 % in safe locations on average, while these success rates are 63 and 44 % when these hazard elements were treated as mutually independent.

Probabilistic seismic hazard assessment of Eastern Marmara Region

The objective of this study is to evaluate the seismic hazard in Eastern Marmara Region using an improved probabilistic seismic hazard assessment methodology. Two significant improvements over the previous seismic hazard assessment practices are accomplished in this study: advanced seismic source characterization models in terms of source geometry and recurrence relationships are developed, and improved global ground motion models (NGA-W1 models) are employed to represent the ground motion variability. Planar fault segments are defined and a composite magnitude distribution model is used for all seismic sources in the region to properly represent the characteristic behavior of the North Anatolian Fault without the need for an additional background zone. Multi-segment ruptures are considered using the rupture model proposed by the Working Group on California Earthquake Probabilities (2003). Events in the earthquake catalogue are attributed to the fault zones and scenario weights are determined by releasing the accumulated seismic energy. The uniform hazard spectra at 10 % probability of exceedance in 50 years hazard level for different soil conditions (soil and rock) are revealed for specific locations in the region (Adapazari, Duzce, Gemlik, Izmit, Iznik and Sapanca). Hazard maps of the region for rock site conditions at the selected hazard levels are provided to allow the readers perform site-specific hazard assessment and develop site-specific design spectrum for local site conditions.

Improved landslide‐tsunami prediction: Effects of block model parameters and slide model

AbstractSubaerial landslide‐tsunamis and impulse waves are caused by mass movements impacting into a water body, and the hazards they pose have to be reliably assessed. Empirical equations developed with physical Froude model studies can be an efficient method for such predictions. The present study improves this methodology and addresses two significant shortcomings in detail for the first time: these are the effect of three commonly ignored block model parameters and whether the slide is represented by a rigid block or a deformable granular material. A total of 144 block slide tests were conducted in a wave flume under systematic variation of three important block model parameters, the slide Froude number, the relative slide thickness, and the relative slide mass. Empirical equations for the maximum wave amplitude, height, and period as well as their evolution with propagation distance are derived. For most wave parameters, remarkably small data scatter is achieved. The combined influence of the three block model parameters affects the wave amplitude and wave height by up to a factor of two. The newly derived equations for block slides are then related to published equations for granular slides. This comparison reveals that block slides do not necessarily generate larger waves than granular slides, as often argued in the technical literature. In fact, it is shown that they may also generate significant smaller waves. The new findings can readily be integrated in existing hazard assessment methodologies, and they explain a large part of the discrepancy between previously published data.

Quantitative assessment of the differential coastal vulnerability associated to oil spills

The risk associated with a given hazard (natural or technological) generally results from the interaction between the hazard potential and the vulnerability. This paper is centred on the assessment of the vulnerability variable. A quantitative vulnerability assessment and mapping methodology is proposed, with two main specificities: (1) it is hazard- and spatially-centred (respectively, oil spills and coastal areas) and; (2) the spatial segregation level used is the municipality. Due to the geographic context of the Portuguese mainland coast, the proposed methodology was applied in an attempt to illustrate the spatial distribution and the degree of the vulnerability associated to oil spills for mainland Portugal coastal municipalities. A final map is presented together with other informative elements. Analysis and discussion of the results allows for the understanding that: (1) there is a very heterogeneous and differential distribution of the degree of vulnerability to oil spills along the Portuguese coastline; (2) the application of specific hazard-centred and spatially-centred vulnerability assessment methodologies, comprising multi-dimensional indicators (e.g., geographic, ecological, demographic, social and economic), produces more robust and realistic results, highlighted by a thorough and spatially detailed analysis; and (3) future research is required on vulnerability assessment in Portugal; along side, hazard potential assessment methodologies must also be developed in order to create a final risk profile, which can be an extremely useful tool in spatial planning and management.

Screening tests for hazard classification of complex waste materials – Selection of methods

In this study we describe the development of an alternative methodology for hazard characterization of waste materials. Such an alternative methodology for hazard assessment of complex waste materials is urgently needed, because the lack of a validated instrument leads to arbitrary hazard classification of such complex waste materials. False classification can lead to human and environmental health risks and also has important financial consequences for the waste owner. The Hazardous Waste Directive (HWD) describes the methodology for hazard classification of waste materials. For mirror entries the HWD classification is based upon the hazardous properties (H1–15) of the waste which can be assessed from the hazardous properties of individual identified waste compounds or – if not all compounds are identified – from test results of hazard assessment tests performed on the waste material itself. For the latter the HWD recommends toxicity tests that were initially designed for risk assessment of chemicals in consumer products (pharmaceuticals, cosmetics, biocides, food, etc.). These tests (often using mammals) are not designed nor suitable for the hazard characterization of waste materials. With the present study we want to contribute to the development of an alternative and transparent test strategy for hazard assessment of complex wastes that is in line with the HWD principles for waste classification. It is necessary to cope with this important shortcoming in hazardous waste classification and to demonstrate that alternative methods are available that can be used for hazard assessment of waste materials. Next, by describing the pros and cons of the available methods, and by identifying the needs for additional or further development of test methods, we hope to stimulate research efforts and development in this direction. In this paper we describe promising techniques and argument on the test selection for the pilot study that we have performed on different types of waste materials. Test results are presented in a second paper.As the application of many of the proposed test methods is new in the field of waste management, the principles of the tests are described. The selected tests tackle important hazardous properties but refinement of the test battery is needed to fulfil the a priori conditions.

Uncertainty in floodplain delineation: expression of flood hazard and risk in a Gulf Coast watershed

AbstractThis paper investigates the development of flood hazard and flood risk delineations that account for uncertainty as improvements to standard floodplain maps for coastal watersheds. Current regulatory floodplain maps for the Gulf Coastal United States present 1% flood hazards as polygon features developed using deterministic, steady‐state models that do not consider data uncertainty or natural variability of input parameters. Using the techniques presented here, a standard binary deterministic floodplain delineation is replaced with a flood inundation map showing the underlying flood hazard structure. Additionally, the hazard uncertainty is further transformed to show flood risk as a spatially distributed probable flood depth using concepts familiar to practicing engineers and software tools accepted and understood by regulators. A case study of the proposed hazard and risk assessment methodology is presented for a Gulf Coast watershed, which suggests that storm duration and stage boundary conditions are important variable parameters, whereas rainfall distribution, storm movement, and roughness coefficients contribute less variability. The floodplain with uncertainty for this coastal watershed showed the highest variability in the tidally influenced reaches and showed little variability in the inland riverine reaches. Additionally, comparison of flood hazard maps to flood risk maps shows that they are not directly correlated, as areas of high hazard do not always represent high risk. Copyright © 2012 John Wiley & Sons, Ltd.

Use of the SSHAC methodology within regulated environments: Cost-effective application for seismic characterization at multiple sites

Abstract Essential elements of license applications and safety reviews for nuclear facilities are quantifications of earthquake and other natural hazards. A Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 or 4 process provides regulatory assurance that the hazard assessment considers all data and models proposed by members of the technical community and the associated uncertainties have been properly quantified. The SSHAC process has been endorsed as an acceptable hazard assessment methodology in US NRC regulatory guidance. Where hazard studies are required for multiple sites, regional SSHAC Level 3 or 4 studies followed by site-specific Level 2 refinements can provide major benefits in cost and duration.

Volcanic and Tectonic Hazard Assessment for Nuclear Facilities

Many of the scientists and engineers currently involved in natural hazards assessment for nuclear facilities are specialists in one type of hazard, such as seismic or volcanic hazards. In addition to thorough coverage of these two specialties, Volcanic and Tectonic Hazard Assessment for Nuclear Facilities (the book) brings together other hazard issues related to tectonic and volcanic processes (subsidence, uplift, and tsunamis) and to processes not directly related to tectonism or volcanism (glacial isostatic adjustments, erosion, sea-level change, and storm surge). One of the values of the book is the comprehensive look at these diverse issues and the efforts that have been made to quantify and model them. The introductory chapters provide context for those that follow and present reviews of tectonic and volcanic processes. Other chapters deal with seismic and volcanic hazard assessment methodology, development of regulatory guidance, special issues at coastal sites (tsunami, storm surge, sea-level changes), site selection for both reactors and geologic repositories in Japan, design of a deep repository in Scandinavia, vertical tectonics and associated erosion and burial, glacial isostatic adjustments, volcanic hazards, and consequences (risk) for the proposed U.S. Yucca Mountain repository, volcanic hazards for a nuclear reactor in the Philippines, and volcanic hazards in the eastern Snake River Plain of Idaho. One of the main themes of the book is the description of spatial density and demonstration of its use, as an alternative to zonation models, for both seismic and volcanic hazards assessment. Case histories for the use of spatial density are presented for volcanic hazards for Yucca Mountain, Japan, and the eastern Snake River Plain of Idaho and for seismic hazards in England. The flexibility of the method to evaluate multiple models (i.e., different event definitions, different kernel functions, different kernel bandwidths, and different conceptual models arising from …

Storm-induced coastal hazard assessment at regional scale: application to Catalonia (NW Mediterranean)

Abstract. A methodology for coastal hazard assessment at regional scale is presented and applied to the Catalan coast (NW Mediterranean). The method separately evaluates erosion and inundation hazards by using wave time series and beach characteristics (slope and sediment grain size). Obtained hazard time series are fitted to extreme probability distributions for different coastal sectors which are defined in function of local wave climate. This approach allows to compare the spatial variation of hazard intensities for a given probability of occurrence and, thus, to objectively identify the most hazardous areas along the coast in terms of erosion and inundation. Obtained results indicate that the coast north of Barcelona is more hazardous than the southern coast regarding inundation for any given probability. With respect to storm-induced erosion, the central coast of Catalonia is the less hazardous area, although spatial variations in erosion along the coast are smaller than the observed for inundation.

A new methodology for flood hazard assessment considering dike breaches

This study focuses on development and application of a new modeling approach for a comprehensive flood hazard assessment along protected river reaches considering dike failures. The proposed Inundation Hazard Assessment Model (IHAM) represents a hybrid probabilistic‐deterministic model. It comprises three models that are coupled in a dynamic way: (1) 1D unsteady hydrodynamic model for river channel and floodplain between dikes; (2) probabilistic dike breach model which determines possible dike breach locations, breach widths and breach outflow discharges; and (3) 2D raster‐based inundation model for the dike‐protected floodplain areas. Due to the unsteady nature of the 1D and 2D models and runtime coupling, the interdependence between the hydraulic loads on dikes at various locations along the reach is explicitly considered. This ensures a more realistic representation of the fluvial system dynamics under extreme conditions compared to the steady approaches. The probabilistic dike breach model describes dike failures due to three failure mechanisms: overtopping, piping and slope instability caused by seepage flow through the dike core (micro‐instability). The 2D storage cell model computes various flood intensity indicators such as water depth, flow velocity, and inundation duration. IHAM is embedded in a Monte Carlo simulation in order to account for the natural variability of the input hydrograph form and the randomness of dike failures. Besides binary (wet/dry) inundation patterns, IHAM generates new probabilistic flood hazard maps for each intensity indicator and the associated uncertainty bounds. Furthermore, the novel probabilistic dike hazard maps indicate the failure probability of dikes for each considered breach mechanism.

A new seismic hazard assessment in the region of Andalusia (Southern Spain)

A probabilistic seismic hazard assessment of Andalusia (Southern Spain) in terms of peak ground acceleration, PGA, and spectral accelerations, SA(T), is presented in this paper. In contrast to most of the previous studies in the region, which were performed for PGA, making use of Intensity-to-PGA relationships, hazard was here calculated in terms of magnitude, using published spectral ground-motion models. Moreover, we considered different ground-motion models for the Atlantic sources, since the attenuation of those motions seems to be slower, as evidenced in the case of the extensive macroseismic areas of earthquakes like those occurred in the years 1755, 1969 and 2007. A comprehensive review of the seismic catalogue and of the seismogenic models proposed for the region was carried out, including those for Northern Africa, which is part of the influence area. Hazard calculations were performed following the Probabilistic Seismic Hazard Assessment (PSHA) methodology using a logic tree, which accounts for six different seismic source zonings and five different ground-motion attenuation relationships. Hazard maps in terms of PGA and SA (0.2 s) and SA (1 s) and coefficient of variation (COV) maps, for the 475-year return period were first obtained in rock sites. A geotechnical classification and amplification factors were proposed and new hazard maps including local effects were represented, showing PGA values ranging from 24 to 370 cm/s2 for the whole Andalusian territory, with the highest expected values (PGA > 300 cm/s2) in some parts of the Granada Province and in the town of Velez Malaga. Lowest values (PGA < 50 cm/s2) correspond to some towns of the Huelva and Cordoba provinces. The inclusion of soil effects provides a more detailed picture of the actual hazard the region is subjected to.

Rockfall hazard analysis using LiDAR and spatial modeling

Rockfalls have been significant geohazards along the Canadian Class 1 Railways (CN Rail and CP Rail) since their construction in the late 1800s. These rockfalls cause damage to infrastructure, interruption of business, and environmental impacts, and their occurrence varies both spatially and temporally. The proactive management of these rockfall hazards requires enabling technologies. This paper discusses a hazard assessment strategy for rockfalls along a section of a Canadian railway using LiDAR and spatial modeling. LiDAR provides accurate topographical information of the source area of rockfalls and along their paths. Spatial modeling was conducted using Rockfall Analyst, a three dimensional extension to GIS, to determine the characteristics of the rockfalls in terms of travel distance, velocity and energy. Historical rockfall records were used to calibrate the physical characteristics of the rockfall processes. The results based on a high-resolution digital elevation model from a LiDAR dataset were compared with those based on a coarse digital elevation model. A comprehensive methodology for rockfall hazard assessment is proposed which takes into account the characteristics of source areas, the physical processes of rockfalls and the spatial attribution of their frequency and energy.

Three Cups of Tea: Building Collaborations to Assess Earthquake Hazard in Pakistan: Modern Methods in Seismic Hazard Assessment; Nagarkot, Nepal, 8–12 June 2009

The M7.6 Muzaffarabad, Pakistan, earthquake struck the Pakistani Kashmir on 8 October 2005, claiming more than 80,000 lives. The earthquake underscored two points about earthquake hazard in Pakistan: first, that it is high, and, second, that it is poorly understood. In Karachi, for example, hazard is generally considered to be low, yet this rapidly growing megacity is as close to a major strike‐slip fault system as Los Angeles is to the San Andreas fault.The Pakistani engineering community has sought guidance from seismologists on improved characterization of seismic hazard. This requires both improved hazard assessment methodology and improved constraints on the critical inputs to seismic hazard maps, for example, assessment of fault slip rates and geological site characterization. These inputs are currently unavailable. Efforts to map seismicity and attenuation and to estimate fault slip rates have been hampered by political instability. Yet there is no shortage of intellectual energy—Pakistan boasts an eager community of trained earthquake professionals.

Risk-relevant indices for the characterization of persistence of chemicals in a multimedia environment

The present research study proposes a new set of appropriately defined indices for the characterization of persistence of chemicals in a multimedia environment that prominently figures as a key exposure-based indicator within contemporary frameworks of chemical hazard and risk assessment, as well as recent international regulatory initiatives. Effectively overcoming some of the limitations associated with traditional approaches that could lead to a potential misclassification of chemical substances, the proposed set of persistence indices retain also a conceptually insightful and computational appeal. Conceptually inspired by certain measures/indices for the characteristic time found in classic dynamic systems theory, and technically relying on notions and methods from the theory of matrices, the new performance indices can be easily calculated on the basis of a dynamic multimedia environmental model and the aid of a software package such as MATLAB. In particular, an extension of the notion of equivalence width as a quantitative proxy of overall persistence is introduced, that captures the dynamic history of the chemical's environmental behavior, while remaining independent of the particular release pattern and discharge conditions (thus overcoming the standardization difficulties encountered when a large number of chemicals need to be first screened and classified in a tiered hazard assessment methodology). Furthermore, a second persistence index is introduced whose value can be analytically calculated through the solution of a simple Lyapunov matrix equation bearing some resemblance to certain measures of system resilience used in theoretical biology and ecology, yet inspired by system-theoretic notions associated with the Lyapunov framework of analysis in systems science. Furthermore, for both persistence measures a comparison is made with the slowest time-constant associated with the specific chemical dynamics in a multimedia environment, and upper and lower bounds are established. Finally, the proposed persistence indices are calculated on the basis of a standard dynamic multimedia environmental model for various representative cases involving chemicals of particular interest.

Methodology for quantitative hazard assessment for tunnel collapses based on case histories in Korea

In this paper we propose the KICT Tunnel Collapse Hazard Index (KTH-Index), an index system for assessing the hazard level of collapse at a tunnel face. To establish the index system, a logical process is proposed for “objectively” assessing the index based on a sensitivity analysis for a well-arranged database containing past collapse cases. For the sensitivity analysis, a neural network based technique is employed which has no restriction, in contrast to conventional sensitivity analysis based on mathematics or statistics. The proposed process is based on the concept of the interaction matrix, a tool for comprehensively expressing the influences among major factors of consideration. Each component of the interaction matrix represents the influential sensitivity between both factors horizontally and vertically linked on the matrix. Since the KTH-Index is assessed based on a database compiled and constructed from collapsed tunnel sites, reliability is compromised for collapse modes and characteristics of sites that are not included in the database. In addition, the characteristics of data available in the database in terms of each major factor must be understood prior to applying the proposed index. Accordingly, this paper includes a basic statistic of the data prepared for the study. The assessment system is applied to the section of the SYK tunnel where large-scale collapses have already occurred, and it is found that the predicted hazard levels are in good agreement with the field data already known.

Real‐time earthquake detection and hazard assessment by ElarmS across California

ElarmS is a network‐based methodology for rapid earthquake detection, location and hazard assessment in the form of magnitude estimation and peak ground motion prediction. The methodology is currently being tested as part of the real‐time seismic system in California leveraging the resources of the California Integrated Seismic Network (CISN) and the Advanced National Seismic System. A total of 603 velocity and acceleration sensors at 383 sites across the state stream waveform data to ElarmS processing modules at three network processing centers where waveforms are reduced to a few parameters. These parameters are then collected and processed at UC Berkeley to provide a single statewide prediction of future ground shaking that is updated every second. The system successfully detected the Mw 5.4 Alum Rock earthquake in northern California for which it generated an accurate hazard prediction before peak shaking began in San Francisco. It also detected the Mw 5.4 Chino Hills earthquake in southern California. The median system latency is currently 11.8 sec; the median waveform data latency is 6.5 sec.

Slope Stability Hazard Assessment and Mitigation Methodology Along Eastern Desert Aswan-CairoHighway, Egypt

The highway between Aswan and Cairo on the eastern bank of the Nile Valley is one of the most used highways in Egypt, connecting most of the governorates with each other. It represents the backbone of Egyptian transportation and commercial traffic. This Highway passes through a two kilometer section of rock cut located 20 km north of New Assiut city. Serious stability and rock fall issues have been recognized in this section in the past few years. In this study the stability of the rock cuts have been evaluated using different techniques including: 1) Determining the most relevant factors affecting slope instability; 2) interpreting the discontinuity data collected from the joint surveys using stereographic projection for the assessment of the modes of failure and determining the potential unstable zones; 3) applying a rock fall simulation program(s) to evaluate the potential rollout distance for the falling rocks; 4) applying the Missouri Rock Fall Hazard Rating System (MORFH RS). Finally, the most optimum mitigation method that will decrease and minimize the consequences of slope instability was determined. This study reveals that the cut needs to be mitigated because of the ongoing slope instability present in some areas, including planar and wedge slides and raveling rock falls. It was found that the unstable rock areas create serious safety hazards to traffic.

SASHA: A Computer Program to Assess Seismic Hazard from Intensity Data

Research Article| September 01, 2008 SASHA: A Computer Program to Assess Seismic Hazard from Intensity Data Vera D'Amico; Vera D'Amico Istituto Nazionale di Geofisica e Vulcanologia via della Faggiola, 32 56126 Pisa, Italy damico@pi.ingv.it (V.D.) Search for other works by this author on: GSW Google Scholar Dario Albarello Dario Albarello University of Siena, Department of Earth Sciences via Laterina, 8 53100 Siena, Italy albarello@unisi.it (D.A.) Search for other works by this author on: GSW Google Scholar Seismological Research Letters (2008) 79 (5): 663–671. https://doi.org/10.1785/gssrl.79.5.663 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Vera D'Amico, Dario Albarello; SASHA: A Computer Program to Assess Seismic Hazard from Intensity Data. Seismological Research Letters 2008;; 79 (5): 663–671. doi: https://doi.org/10.1785/gssrl.79.5.663 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search The evaluation of seismic hazard over wide territories is a basic tool for planning activities aimed at earthquake damage mitigation. This is commonly performed through probabilistic approaches based on the statistical analysis of past seismicity. Among these, due to its wide application worldwide, the Cornell-McGuire approach (Cornell 1968; McGuire 1978) has become a kind of “standard” methodology for probabilistic seismic hazard assessment (PSHA). In Italy, several national seismic hazard maps were produced in recent years (Slejko et al. 1998; Albarello et al. 2000; MPS Working Group 2004) by following this procedure as implemented... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Evaluation of PGA for Tirana city

We applied deterministic and probabilistic methodologies for seismic hazard assessment at Tirana city, expressed in terms of horizontal peak ground acceleration (PGA). The deterministic values of PGA are determined according to the scenario R =6 . 4k m andMmax =6 .0, while the probabilistic ones have been assessed applying the smoothed seismicity approach. The results that derive from the two methodologies show equal values of PGA for the selected site inside Tirana city and higher than the PGA values established by the official maps as well as the actual seismic coefficients that are being applied by the actually in force national design code KTP–N.2–89 for Tirana area.