A preliminary investigation of tsunami hazard

1982 ◽  
Vol 72 (6A) ◽  
pp. 2323-2337
Author(s):  
I-Chen Lin ◽  
Chi C. Tung
Keyword(s):  
Seismic Moment ◽  
Preliminary Investigation ◽  
Wave Theory ◽  
Sensitivity Study ◽  
Tsunami Hazard ◽  
Submarine Earthquakes ◽  
Maximum Elevation ◽  
Motion Characteristics ◽  
A Site ◽  
Seismological Model

abstract A method for determining tsunami hazard is presented using simple seismological and hydrodynamic models. The seismological model assumes that submarine earthquakes of the dipstrike type can occur, with equal likelihood, anywhere along a well-defined straight fault and that the site under consideration lies on the perpendicular bisector of and far removed from the fault. The ground dislocation is circular in the horizontal plane, and the vertical offset is uniform. The radius of the circle and the vertical offset are related to seismic moment which is assumed to be random. The hydrodynamic model is based on linear dispersive wave theory. It is assumed that the earth is flat, water depth constant, and ocean infinite in horizontal extent. The maximum elevation of water surface of the leading wave is related to ground motion characteristics (or seismic moment) and the distance from the site to the source. The probability of the event that the water elevation at a site exceeds an arbitrary but specified level is then derived and computed. A sensitivity study is performed to determine the importance of various parameters.

scholarly journals STUDIES OF TSUNAMI HAZARD

1986 ◽  
Vol 1 (20) ◽  
pp. 192
Author(s):  
I. Chen Lin ◽  
C.C. Tung
Keyword(s):  
Wave Theory ◽  
Sensitivity Study ◽  
Tsunami Hazard ◽  
Constant Depth ◽  
Hydrodynamic Models ◽  
Ground Displacement ◽  
Plan View ◽  
Indirect Approach ◽  
The Earth ◽  
Long Wave

Tsunami hazard is investigated using the indirect approach with simple seismological and hydrodynamic models. It is assumed that earthquakes of random magnitude may originate anywhere with equal likelihood from a single straight fault and the site is located on the perpendicular plane bisecting the fault. The ground displacement is instantaneous and consists of a block uplift type of movement which may be circular or elongated in the plan view. The hydrodynamic model is based on linear long wave theory wherein the ocean is of constant depth and infinite in the horizontal extent, and the earth is flat. Tsunami hazard is computed for various values of the parameters and a sensitivity study is carried out to examine the effect of certain parameters on hazard.

scholarly journals The Departure Characteristics of Traffic Flow at the Signalized Intersection

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Zhaowei Qu ◽  
Yan Xing ◽  
Hongyu Hu ◽  
Yuzhou Duan ◽  
Xianmin Song ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Wave Model ◽  
Wave Theory ◽  
Signalized Intersection ◽  
Departure Process ◽  
Dispersion Process ◽  
Spatiotemporal Model ◽  
Quantitative Calculation ◽  
Traffic Wave ◽  
Motion Characteristics

The motion characteristics of the leading vehicle and the following vehicles of the traffic flow at the typical urban intersections are qualitatively analyzed through the kinematical equation and the traffic wave theory. Then, the motion characteristic of the whole traffic flow during the dispersion process is also studied. Based on the spatiotemporal model of kinematics in the departure process and traffic wave model in the dispersion process proposed, the change of the leading vehicle of the departure process and the time of the following vehicles reaching to the stable speed as well as the relationship between the green time and the departure vehicle number at the intersection are acquired. Furthermore, according to the qualitative analysis and the quantitative calculation of the departure traffic flow at the signalized intersection, the dispersion characteristic of traffic flow at the signalized intersection was studied and analyzed, which provides reliable theoretical basis for traffic signal setting at the intersection.

Monte Carlo methods to include the effect of asymmetrical uncertainty sources in wind farm yield assessment

2018 ◽  
Vol 42 (6) ◽  
pp. 624-632 ◽  
Author(s):  
Alexander Gleim ◽  
Rolf-Erik Keck ◽  
John Amund Lund
Keyword(s):  
Monte Carlo ◽  
Wind Speed ◽  
Energy Production ◽  
Wind Farm ◽  
Sensitivity Study ◽  
Uncertainty Sources ◽  
Industry Standard ◽  
Wind Speed Distribution ◽  
Mean Wind Speed ◽  
A Site

This article presents a method for incorporating the effect on expected annual energy production of a wind farm caused by asymmetric uncertainty distributions of the applied losses and the nonlinear response in turbine production. The necessity for such a correction is best illustrated by considering the effect of uncertainty in the oncoming wind speed distribution on the production of a wind turbine. Due to the shape of the power curve, variations in wind speed will result in a skewed response in annual energy production. For a site where the mean wind speed is higher than 50% of the rated wind speed of the turbine (in practice all sites with sufficiently high wind speed to motivate the establishment of a wind farm), a reduction in mean wind will cause a larger reduction in annual energy production than a corresponding increase in mean wind would increase the annual energy production. Consequently, the expected annual energy production response when considering the uncertainty of the wind will be lower than the expected annual energy production based on the most probable incoming wind. This difference is due to a statistical bias in the industry standard methods to calculate expected annual energy production of a wind farm, as implemented in tools in common use in the industry. A method based on a general Monte Carlo approach is proposed to calculate and correct for this bias. A sensitivity study shows that the bias due to wind speed uncertainty and nonlinear turbine response will be on the order of 0.5% – 1.5% of expected annual energy production. Furthermore, the effect on expected annual energy production due to asymmetrical distributions of site specific losses, for example, loss of production due to ice, can constitute additional losses of several percent.

Risk-Based Radiological Site Investigation and Assessment Methodology for the Sellafield Site, Cumbria, UK

2003 ◽  
Author(s):  
Hamdi El-Ghonemy ◽  
Candida Lean ◽  
Alexander G. Lee
Keyword(s):  
Retrieval System ◽  
Preliminary Investigation ◽  
Site Investigation ◽  
Hazard Identification ◽  
Assessment Process ◽  
Preliminary Assessment ◽  
Unique Approach ◽  
Working Practices ◽  
Identification Stage ◽  
A Site

A preliminary assessment of the Sellafield site in Cumbria was undertaken to provide the information for the hazard identification stage in the environmental risk assessment process. This preliminary investigation has been crucial to understanding the site’s history, the zones of potential risk and for the design of a site investigation. The formalised assessment strategy that has subsequently been developed by BNFL for the Sellafield study has drawn upon UK and international guidance to take into account the size of the site and the anticipated complexity of issues. The approach presented represents an advance on existing working practices in contaminated land investigations. The use of a generic list of Features, Events and Processes (FEPs) has been adopted to ensure the systematic and comprehensive appraisal of all relevant uncertainties and sources of risk. Proforma have also been developed to provide a data management and retrieval system that is transparent for quality assurance purposes. This unique approach facilitates the development of conceptual site models as new data become available during the site investigation. It also aids in the development and justification of alternative site conceptualisations and in the early identification of data and interpretative uncertainty.

scholarly journals Sensitivity analysis of gas leakage through a fault zone during subsurface gas storage in porous formations

2019 ◽  
Vol 49 ◽  
pp. 155-164
Author(s):  
Firdovsi Gasanzade ◽  
Sebastian Bauer ◽  
Wolf Tilmann Pfeiffer
Keyword(s):  
Fault Zone ◽  
Gas Flow ◽  
Damage Zone ◽  
Gas Storage ◽  
Sensitivity Study ◽  
Gas Leakage ◽  
The North ◽  
Entry Pressure ◽  
Capillary Entry Pressure ◽  
A Site

Abstract. Subsurface gas storage in porous media is a viable option to mitigate shortages in energy supply in systems largely based on renewable sources. Fault systems adjacent to or intersecting with gas storage could potentially result in a leakage of stored gas. Variations in formation pressure during a storage operation can affect the gas leakage rates, requiring a site and scenario specific assessment. In this study, a geological model of an existing structure in the North German Basin (NGB) is developed, parameterised and a methane gas storage operation is simulated. Based on the observed storage pressure, a sensitivity study aimed at determining gas leakage rates for different parametrisations of the fault damage zone is performed using a simplified 2-D model. The leakage scenario simulations show a strong parameter dependence with the fault acting as either a barrier or a conduit for gas flow. Furthermore, the storage operation greatly affects the gas leakage rates for a given parametrisation with significant leakage only during the injection periods and thus during increased overpressures in the storage formation. During injection, the peak leakage rates can be as high as 2308 Sm3 d−1 for damage zone permeabilities of 10 mD and a capillary entry pressure of 4 bar. Increasing capillary entry pressure results in a sealing effect. If the capillary entry pressure is scaled according to the damage zone permeability, peak leakage rates can be higher, i.e. 3240 Sm3 d−1 for 10 mD and 0.13 bar. During withdrawal periods, the pressure gradient between a storage formation and a fault zone is reduced or even reversed, resulting in greatly reduced leakage rates or even a temporary stop of the leakage. Total leakage volume from storage formation was assessed based on the 2-D study by considering the exposure of the gas-filled part of the storage formation to the fault zone and subsequently compared with gas in place volume.

Ground-motion characteristics estimated from spectral ratio between horizontal and vertical components of microtremor

1998 ◽  
Vol 88 (1) ◽  
pp. 228-241 ◽  
Author(s):  
Katsuaki Konno ◽  
Tatsuo Ohmachi
Keyword(s):  
Amplification Factor ◽  
Ground Surface ◽  
Spectral Ratio ◽  
Theoretical Background ◽  
Smoothing Function ◽  
Amplification Factors ◽  
Rayleigh And Love Waves ◽  
Motion Characteristics ◽  
A Site ◽  
Improved Technique

Abstract The spectral ratio between horizontal and vertical components (H/V ratio) of microtremors measured at the ground surface has been used to estimate fundamental periods and amplification factors of a site, although this technique lacks theoretical background. The aim of this article is to formulate the H/V technique in terms of the characteristics of Rayleigh and Love waves, and to contribute to improve the technique. The improvement includes use of not only peaks but also troughs in the H/V ratio for reliable estimation of the period and use of a newly proposed smoothing function for better estimation of the amplification factor. The formulation leads to a simple formula for the amplification factor expressed with the H/V ratio. With microtremor data measured at 546 junior high schools in 23 wards of Tokyo, the improved technique is applied to mapping site periods and amplification factors in the area.

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