Sampling uncertainties and source <Emphasis Type="Italic">b</Emphasis> likelihood for the Gutenberg-Richter <Emphasis Type="Italic">b</Emphasis> value from the Aki-Utsu method     

F. A. Nava  L. Ávila-Barrientos  V. H. Márquez-Ramírez  I. Torres  F. R. Zúñiga 《Journal of Seismology》2018,22(1):315-324

The Aki-Utsu method of Gutenberg-Richter (G-R) b value estimation is often misapplied so that estimations not using the G-R histogram are often meaningless because they are not based on adequate samples. We propose a method to estimate the likelihood Pr(b?b _m , N, M ₁, M ₂) that an observed b _m estimate, based on a sample of N magnitudes within an [M ₁????≤?ΔM/2,?M ₂?+?ΔM/2) range, where ΔM?=?0.1 is the usual rounding applied to magnitudes, is due to a “true” source b value, b, and use these likelihoods to estimate source b ranges corresponding to various confidence levels. As an example of application of the method, we estimate the b values before and after the occurrence of a 7.4-magnitude earthquake in the Mexican subduction zone, and find a difference of 0.82 between them with 100% confidence that the b values are different.  相似文献   

PAR(<Emphasis Type="Bold">p</Emphasis>)-vine copula based model for stochastic streamflow scenario generation     

Guilherme?PereiraEmail author  álvaro?Veiga 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(3):833-842

Synthetic streamflow data is vital for the energy sector, as it feeds stochastic optimisation models that determine operational policies. Considered scenarios should differ from each other, but be the same from a statistical point of view, i.e., the scenarios must preserve features of the original time series such as the mean, variance, and temporal dependence structures. Traditionally, linear models are applied for this task. Recently, the advent of copulas has led to the emergence of an alternative that overcomes the drawbacks of linear models. In this context, we propose a methodology based on vine copulas for the stochastic simulation of periodic streamflow scenarios. Copula-based models that focus on single-site inflow simulation only consider lag-one time dependence. Therefore, we suggest an approach that incorporates lags that are greater than one. Furthermore, the proposed model deals with the strong periodicity that is commonly present in monthly streamflow time series. The resulting model is a non-linear periodic autoregressive model. Our results indicate that this model successfully simulates scenarios, preserving features that are observed in historical data.  相似文献   

Probabilistic leak detectability assessment via state estimation in water transport networks     

Sarai?DíazEmail authorView author&#;s OrcID profile  Roberto?Mínguez  Javier?González 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(7):2111-2128

Leak detectability or leakage awareness refers to the capability of sensing losses from a water supply system. Several methods exist in the technical literature to tackle this problem, but only few address it with a state estimation approach. The aim of this paper is to present a new methodology that enables probabilistic assessment of the extent to which water loss could be detected using state estimation by only analysing a single hydraulic state, i.e. one time period. Significant leaks are sensed by identifying unusually high normalised state estimation residuals, which can be identified based on the largest normalised residual test. More specifically, the probability of detecting leaks is computed here by working with the multivariate distribution among measurements and estimates to take into account the noisy nature of measurements with an analytical approach rather than with sampling experiments, which are time-consuming. The methodology set out herein also provides a procedure to systematically assess the minimum leak that could be detected in different parts of the network for a specific measurement setting and operating condition. The method has been applied to a water transport network case study to show its potential and to highlight the usefulness of such a tool for practitioners. The limitations of such a methodology are also discussed, including its possible use for on-line leak detection strategies.  相似文献   

On the significance of the climate-dataset time resolution in characterising wind-driven rain and simultaneous wind pressure. Part I: scalar approach     

Pérez-Bella  José M.  Domínguez-Hernández  Javier  Cano-Suñén  Enrique  del Coz-Díaz  Juan J.  Alonso-Martínez  Mar 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(6):1783-1797

Stochastic Environmental Research and Risk Assessment - The joint action of wind-driven rain and wind pressure is the main cause of water penetration in building facades, which causes various...  相似文献   

Analysis of soil drying incorporating a constitutive model for curling     

Maedo  Michael  Sánchez  Marcelo  Aljeznawi  Duaa  Manzoli  Osvaldo  Guimarães  Leonardo J. N.  Cleto  Pedro Rogério 《Acta Geotechnica》2020,15(9):2619-2635

This paper focuses on the shrinkage behavior of soil specimens involving sand, kaolinite, and kaolinite/sand mixtures subjected to desiccation under controlled conditions. Both, free and restrained shrinkage conditions are studied. The experiments show that pure soils do not curl upon unrestrained shrinkage; however, (under the same conditions) kaolinite/sand mixtures exhibited a marked curling. Furthermore, the mixture with the higher sand content broke through the middle of the sample after displaying a significant curling. Soils subjected to restricted shrinkage developed cracks with slight curling. To simulate the observed behavior, a mechanical model able to reproduce the detachment of the soil sample from the mold is proposed in this work and implemented in a fully coupled hydro-mechanical finite-element code. It is concluded that suction and differential shrinkage are key factors influencing the curling behavior of soils. The proposed framework was able to satisfactorily explain and reproduce the different stages and features of soil behavior observed in the experiments.

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Geological Facies Recovery Based on Weighted $$\ell _1$$ ℓ 1 -Regularization     

Calderon  Hernan  Santibañez  Felipe  Silva  Jorge F.  Ortiz  Julián M.  Egaña  Alvaro 《Mathematical Geosciences》2020,52(5):593-617

Mathematical Geosciences - A weighted compressed sensing (WCS) algorithm is proposed for the problem of channelized facies reconstruction from pixel-based measurements. This strategy integrates...  相似文献   

Geomechanics of hazardous landslides   总被引：1，自引：1，他引：0  

POISEL Rainer BEDNARIK Martin HOLZER Rudolf LISCAK Pavel 《山地科学学报》2005,2(3):211-217

A catalogue of possible landslide initial failure mechanisms, taking into account the geological setting and the geometry of the slope, the joint structure, the habitus of the rock blocks, as well as the mechanical behaviour of the rocks and of the rock mass （deformation and strength parameters）, is presented. Its aim is to give geologists as well as engineers the opportunity to compare phenomena in the field and phenomena belonging to particular mechanisms and to find the mechanism occurring. The presented catalogue of initial landslide mechanisms only comprises the mechanisms having a clearly defined mechanical model that can be divided into empirical relations and into mechanical models, as well as an overview of run out models, which can be divided into empirical relations and into mechanical models.  相似文献   

Tsunami hydrodynamic force on a building using a SPH real-scale numerical simulation     

Klapp  Jaime  Areu-Rangel  Omar S.  Cruchaga  Marcela  Aránguiz  Rafael  Bonasia  Rosanna  Godoy  Mauricio J.  Silva-Casarín  Rodolfo 《Natural Hazards》2020,100(1):89-109

Natural Hazards - One of the most important aspects in tsunami studies is the behaviour of the wave when it approaches the coast. Information on physical parameters that characterize waves is often...  相似文献   

Analysis of the trends in precipitation and precipitation concentration in some climatological stations of Mexico from 1960 to 2010     

Núñez-González  Gerardo 《Natural Hazards》2020,104(2):1747-1761

Natural Hazards - Analysis of precipitation trends as well as the observed trends in precipitation concentration can be useful tools for the identification of natural hazards. This study aimed to...  相似文献   

Highways protection from flood hazards,a case study: New Tama road,KSA     

Fathy  Ismail  Zeleňáková  Martina  Abd-Elhamid  Hany F. 《Natural Hazards》2020,103(1):479-496

Natural Hazards - Highways in arid regions are highly exposed to damage by floods. This requires intensive analysis of flood quantity, time and direction that can be used to design the suitable...  相似文献