The Sensitivity of Maximum Magnitude Range Parameter in Bedrock Acceleration Calculation for 2500 Years of Return Period, Case Study: Bengkulu Province, Indonesia

Earthquakes occur on faults and create new faults. They also occur on normal, reverse and strike-slip faults. The aim of this work is to suggest a new unified classification of Shallow depth earthquakes based on the faulting styles, and to characterize each class. The characterization criteria include the maximum magnitude, focal depth, b-constant value, return period and relations between magnitude, focal depth and dip of fault plane. Global Centroid Moment Tensor (GCMT) catalog is the source of the used data. This catalog covers the period from Jan.1976 to Dec. 2017. We selected only the shallow (depth less than 70kms) pure, normal, strike-slip and reverse earthquakes (magnitude ≥ 5) and excluded the oblique earthquakes. The majority of normal and strike-slip earthquakes occurred in the upper crust, while the reverse earthquakes occurred throughout the thickness of the crust. The main trend for the derived b-values for the three classes was: b normal fault>bstrike-slip fault>breverse fault. The mean return period for the normal earthquake was longer than that of the strike-slip earthquakes, while the reverse earthquakes had the shortest period. The obtained results report the relationship between the magnitude and focal depth of the normal earthquakes. A negative significant correlation between the magnitude and dip class for the normal and reverse earthquakes is reported. Negative and positive correlation relations between the focal depth and dip class were recorded for normal and reverse earthquakes, respectively. The suggested classification of earthquakes provides significant information to understand seismicity, seismtectonics, and seismic hazard analysis.

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Comparing an insurer's perspective on building damages with modelled damages from pan-European winter windstorm event sets: a case study from Zurich, Switzerland

Natural Hazards and Earth System Science ◽

10.5194/nhess-21-279-2021 ◽

2021 ◽

Vol 21 (1) ◽

pp. 279-299

Author(s):

Christoph Welker ◽

Thomas Röösli ◽

David N. Bresch

Keyword(s):

Open Source ◽

Return Period ◽

Model Building ◽

Information Service ◽

Source Model ◽

Insurance Companies ◽

Risk Models ◽

Risk Modelling ◽

Modelling Approach

Abstract. With access to claims, insurers have a long tradition of being knowledge leaders on damages caused by windstorms. However, new opportunities have arisen to better assess the risks of winter windstorms in Europe through the availability of historic footprints provided by the Windstorm Information Service (Copernicus WISC). In this study, we compare how modelling of building damages complements claims-based risk assessment. We describe and use two windstorm risk models: an insurer's proprietary model and the open source CLIMADA platform. Both use the historic WISC dataset and a purposefully built, probabilistic hazard event set of winter windstorms across Europe to model building damages in the canton of Zurich, Switzerland. These approaches project a considerably lower estimate for the annual average damage (CHF 1.4 million), compared to claims (CHF 2.3 million), which originates mainly from a different assessment of the return period of the most damaging historic event Lothar–Martin. Additionally, the probabilistic modelling approach allows assessment of rare events, such as a 250-year-return-period windstorm causing CHF 75 million in damages, including an evaluation of the uncertainties. Our study emphasizes the importance of complementing a claims-based perspective with a probabilistic risk modelling approach to better understand windstorm risks. The presented open-source model provides a straightforward entry point for small insurance companies.

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Weibull parameter calculation and estimation of wind speeds for the return period: A case study in the Kori and Wolsong NPP areas

Annals of Nuclear Energy ◽

10.1016/j.anucene.2017.04.040 ◽

2017 ◽

Vol 108 ◽

pp. 406-412 ◽

Cited By ~ 3

Author(s):

Jong Kuk Lee ◽

Kwan-Hee Lee ◽

Sung Il Kim ◽

Daesik Yook ◽

Sangmyeon Ahn

Keyword(s):

Return Period ◽

Weibull Parameter ◽

Parameter Calculation ◽

Wind Speeds

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Integrated Workflow for Feasibility Study of Cuttings Reinjection Based on 3D Geomechanics Analysis and Case Study

10.2118/201073-ms ◽

2021 ◽

Author(s):

Xinpu Shen

Keyword(s):

Feasibility Study ◽

Best Practice ◽

Injection Pressure ◽

Accurate Solution ◽

Fault Reactivation ◽

Injection Well ◽

Maximum Magnitude ◽

Richter Scale ◽

Effective Stress Ratio

Abstract This paper presents an integrated workflow for feasibility study of cuttings reinjection (CRI) based on 3D geomechanics analysis. Solutions of various mechanical variables obtained with 3D geomechanics analysis at various level of scale are used as basis for designing parameters of CRI. Solutions of geomechanics analysis provide basis for a feasibility study and/or design of CRI: solution of 3D geostress distribution and the effective stress ratio are the essential factors for selecting the best location of injection well; solution of 1D geomechanics analysis provides basis for choice of true vertical depth (TVD) interval for injection sections; and hydraulic fracturing performed in the framework of 3D geomechanics analysis provides the most accurate solution for both the injection pressure window and fault reactivation related to CRI as well as estimation of seismic behavior. Example of feasibility study of cuttings reinjection with the integrated workflow proposed here is presented with data from a case in offshore West Africa. Solutions of geomechanics analysis are used for decision making at various stages of CRI. There are several faults in this region. The location of the injection well is chosen at a place with principal stress ratio's value at 0.68. The interval of injection well section is chosen as a 140-ft section with center at TVD = 6,700 ft. The numerical solution of injection pressure window is defined with 46 MPa as lower bound and 80 MPa as upper bound. The width of the fracture is 0.069 m, and length and height are 4,000 m and 100 m respectively. The accommodation volume of fluid with cuttings is 2.76×104 m3. The maximum magnitude of Richter scale of the seismicity corresponding to the fault reactivation is 3.15. The case study described in this paper provides an integrated workflow for feasibility study of CRI based on 3D geomechanics analysis. A best practice for this type of CRI design is also presented.

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Global flood hazard map and exposed GDP comparison: a China case study

10.5194/nhess-2020-1 ◽

2020 ◽

Author(s):

Jerom P. M. Aerts ◽

Steffi Uhlemann-Elmer ◽

Dirk Eilander ◽

Philip J. Ward

Keyword(s):

Return Period ◽

Flood Hazard ◽

Regional Scale ◽

Flood Protection ◽

Economic Losses ◽

Return Periods ◽

Hazard Maps ◽

High Exposure ◽

Pluvial Flooding

Abstract. Floods are among the most frequent and damaging natural hazard events in the world. In 2016, economic losses from flooding amounted to $56 bn globally, of which $20 bn occurred in China (Munich Re, 2017). National or regional scale mapping of flood hazard is at present providing an inconsistent and incomplete picture of floods. Over the past decade global flood hazard models have been developed and continuously improved. There is now a significant demand for testing of the global hazard maps generated by these models in order to understand their applicability for international risk reduction strategies and for reinsurance portfolio risk assessments using catastrophe models. We expand on existing methods for comparing global hazard maps and analyse 8 global flood models (GFMs) that represent the current state of the global flood modelling community. We apply our comparison to China as a case study and, for the first time, we include industry models, pluvial flooding, and flood protection standards in the analysis. We find substantial variability between the flood hazard maps in modelled inundated area and exposed GDP across multiple return periods (ranging from 5 to 1500 years) and in expected annual exposed GDP. For example, for the 100 year return period undefended (assuming no flood protection) hazard maps the percentage of total affected GDP of China ranges between 4.4 % and 10.5 % for fluvial floods. For the majority of the GFMs we see only a small increase in inundated area or exposed GDP for high return period undefended hazard maps compared to low return periods, highlighting major limitations in the models’ resolution and their output. The inclusion of industry models which currently model flooding at higher spatial resolution, and which additionally include pluvial flooding, strongly improves the comparison and provides important new benchmarks. Pluvial flooding can increase the expected annual exposed GDP by as much as 1.3 % points. Our study strongly highlights the importance of flood defenses for a realistic risk assessment in countries like China that are characterized by high concentrations of exposure. Even an incomplete (1.74 % of area of China) but locally detailed layer of structural defenses in high exposure areas reduces the expected annual exposed GDP to fluvial and pluvial flooding from 4.1 % to 2.8 %.

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Estimate of Storm Induced Beach Erosion Through the ETS Approach

Volume 2: Structures, Safety and Reliability ◽

10.1115/omae2008-57749 ◽

2008 ◽

Author(s):

Rosaria E. Musumeci ◽

Carla Faraci ◽

Felice Arena ◽

Enrico Foti

Keyword(s):

Return Period ◽

Extreme Events ◽

Coastal Erosion ◽

Beach Erosion ◽

Coastal Protection ◽

Shoreline Retreat ◽

Submerged Breakwater ◽

The One

In the present paper the risk of beach erosion is evaluated by applying the Equivalent Triangular Storm (ETS). The selected case study is ‘La Plaja’ beach located in the South of Catania, Sicily. The proposed approach has shown that when the ETS model is applied, a shoreline retreat has been found which on average overestimates the one obtained by means of actual storm data of about 35%. The model has been applied for the determination of the return period of shoreline recession due to beach erosion during extreme events in order to recover risk maps, which can provide useful information in the planning of coastal interventions. Finally the model has been applied to predict the shoreline retreat in the presence of a submerged breakwater, confirming that the introduction of such coastal protection work strongly limits the risk of coastal erosion.

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Analysis of Problems Related to the Calculation of Flood Frequency Using Rainfall-Runoff Models: A Case Study in Poland

Sustainability ◽

10.3390/su12177187 ◽

2020 ◽

Vol 12 (17) ◽

pp. 7187

Author(s):

Dariusz Młyński

Keyword(s):

Sensitivity Analysis ◽

Return Period ◽

Maximum Flow ◽

High Sensitivity ◽

Flood Frequency ◽

Rainfall Runoff ◽

Model Quality ◽

Retention Capacity

This work aimed to quantify how the different parameters of the Snyder model influence the errors in design flows. The study was conducted for the Kamienica Nowojowska catchment (Poland). The analysis was carried out according to the following stages: determination of design precipitation, determination of design hyetograph, sensitivity analysis of the Snyder model, and quality assessment of the Snyder model. Based on the conducted research, it was found that the Snyder model did not show high sensitivity to the assumed precipitation distribution. The parameters depending on the retention capacity of the catchment had much greater impact on the obtained flow values. The verification of the model quality showed a significant disproportion in the calculated maximum flow values with the assumed return period.

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Return period of extreme rainfall substantially decreases under 1.5 °C and 2.0 °C warming: a case study for Uttarakhand, India

Environmental Research Letters ◽

10.1088/1748-9326/ab0bce ◽

2019 ◽

Vol 14 (4) ◽

pp. 044033 ◽

Cited By ~ 1

Author(s):

Savitri Kumari ◽

Karsten Haustein ◽

Hammad Javid ◽

Chad Burton ◽

Myles R Allen ◽

...

Keyword(s):

Return Period ◽

Extreme Rainfall

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Assessment of overtopping reliability and benefits of a flood detention dam

Canadian Journal of Civil Engineering ◽

10.1139/l08-052 ◽

2008 ◽

Vol 35 (10) ◽

pp. 1177-1182 ◽

Cited By ~ 8

Author(s):

A. Melih Yanmaz ◽

M. Engin Gunindi

Keyword(s):

Return Period ◽

Flood Frequency ◽

Flood Frequency Analysis ◽

Site Specific ◽

Joint Return ◽

Dam Site ◽

Bivariate Gamma Distribution ◽

Project Characteristics ◽

Joint Return Period

There is a growing tendency to assess safety levels of existing dams and to design new dams using probabilistic approaches according to project characteristics and site-specific conditions. This study is a probabilistic assessment of the overtopping reliability of a dam, which will be designed for flood detention purpose, and will compute the benefits that can be gained as a result of the implementation of this dam. In a case study, a bivariate flood frequency analysis was carried out using a five-parameter bivariate gamma distribution. A family of joint return period curves relating the runoff peak discharges to the runoff volumes at the dam site was derived. A number of hydrographs were also obtained under a joint return period of 100 years to observe the variation of overtopping tendency. The maximum reservoir elevation and overtopping reliability were determined by performing a probabilistic reservoir routing based on Monte Carlo simulations.

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