Identification and hazard analysis of landslides triggered by earthquakes and rainfall

This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter of a M 3.9, earthquake that occurred in Tanchang County, Gansu Province, on December 28, 2020. The objective is to identify potential earthquake-induced landslides, assess their scale, and determine their impact range. The study results reveal the successful identification of two potential landslides in the 20 km radius around the epicenter. Through time-series deformation analysis, it was observed that these potential landslides were significantly influenced by both the earthquake and rainfall. Further estimation of these potential landslides indicates maximum depths of 7.4 m and 14.1 m for the failure surfaces, with volumes of 9.02 × 10~4m~3and 25.5 ×10~4m~3, respectively. Finally, based on the simulation analysis of Massflow software, the maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Shangyaai is 12 m, the area of the final accumulation area is 1.75 × 10~4m~2, and the farthest movement distance is 1124 m. The maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Wangshancun is 8 m, the area of the final accumulation area is 7.89 × 10~4m~2, and the farthest movement distance is 742 m.

Hazard analysis system of urban post-earthquake fire based on GIS

The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.

Seismic hazard analysis for central-western Argentina

In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5（Mw） are expected.High values of SA（spectral acceleration）（0.2 and 1 s periods） and PGA（peak ground acceleration） were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures.

Copula joint function and its application in probability seismic hazard analysis

A mature mathematical technique called copula joint function is introduced in this paper, which is commonly used in the financial risk analysis to estimate uncertainty. The joint function is generalized to the n-dimensional Frank’s copula. In addition, we adopt two attenuation models proposed by YU and Boore et al, respectively, and construct a two-dimensional copula joint probabilistic function as an example to illustrate the uncertainty treatment at low probability. The results show that copula joint function gives us a better prediction of peak ground motion than that resultant from the simple linear weight technique which is commonly used in the traditional logic-tree treatment of model uncertainties. In light of widespread application in the risk analysis from financial investment to insurance assessment, we believe that the copula-based technique will have a potential application in the seismic hazard analysis.

Potential rupture surface model and its ap-plication on probabilistic seismic hazard analysis

Potential sources are simplified as point sources or linear sources in current probabilistic seismic hazard analysis （PSHA） methods. Focus size of large earthquakes is considerable, and fault rupture attitudes may have great influence upon the seismic hazard of a site which is near the source. Under this circumstance, it is unreasonable to use the simplified potential source models in the PSHA, so a potential rupture surface model is proposed in this paper. Adopting this model, we analyze the seismic hazard near the Chelungpu fault that generated the Chi-Chi （Jiji） earthquake with magnitude 7.6 and the following conclusions are reached. （1） This model is reasonable on the base of focal mechanism, especially for sites near potential earthquakes with large magnitude; （2） The attitudes of potential rupture surfaces have great influence on the results of probabilistic seismic hazard analysis and seismic zoning.

Application of Hazard Vulnerability Analysis Based on Kaiser Model in Neonatal Breast Milk Management

Objective:To analyze the existing risks in breast milk management at the neonatal department and provide corresponding countermeasures.Methods:22 risk events were identified in 7 risk links in the process of bottle-feeding of breast milk.Hazard Vulnerability Analysis based on the Kaiser model was applied to investigate and evaluate the risk events.Results:High-risk events include breast milk quality inspection,hand hygiene during collection,disinfection of collectors,cold chain management,hand hygiene during the reception,breast milk closed-loop management,and post-collection disposal.Root cause analysis of high-risk events was conducted and breast milk management strategies outside the hospital and within the neonatal department were proposed.Conclusion:Hazard Vulnerability Analysis based on the Kaiser model can identify and assess neonatal breast milk management risks effectively,which helps improve the management of neonatal breast milk.It is conducive to the safe development and promotion of bottle feeding of breast milk for neonates,ensuring the quality of medical services and the safety of children.

Seismic Hazard Analysis of China's Mainland Based on a New Seismicity Model

Based on the seismic source model in the Fifth Generation Seismic Ground Motion Parameters Zonation Map of China(FGSGMPZMC),a new seismic fault model,the new zonation of seismic risk areas(SRAs),and the estimation of seismicity rates for 2021-2030,this study constructed a new time-dependent seismic source model of China’s mainland,and used the probabilistic seismic hazard analysis method to calculate seismic hazard by selecting the ground motion models(GMMs)suitable for seismic sources in China.It also provided the probabilities of China’s mainland being affected by earthquakes of modified Mercalli intensity(MMI)Ⅵ,Ⅶ,Ⅷ,Ⅸ,and≥Ⅹin 2021-2030.The spatial pattern of seismic hazards presented in this article is similar to the pattern of the FGSGMPZMC,but shows more details.The seismic hazards in this study are higher than those in the FGSGMPZMC in the SRAs and fault zones that can produce large earthquakes.This indicates that the seismic source model construction in this study is scientific and reasonable.There are certain similarities between the results in this study and those of Rong et al.(2020)and Feng et al.(2020),but also disparities for specific sites due to differences in seismic source models,seismicity parameters,and GMMs.The results of seismic hazard may serve as parameter input for future seismic risk assessments.The hazard results can also be used as a basis for the formulation of earthquake prevention and mitigation policies for China’s mainland.

Structural failure analysis with CMS-based ground motion selection using innovative cost function and weight factors

The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.

Multi-scenario-based hazard analysis of high temperature extremes experienced in China during 1951-2010

China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density. This article presents a scenario-based analysis method for high temperature extremes aimed at illustrating the latter＇s hazardous potential and exposure across China. Based on probability analysis, high temperature extreme scenarios with return periods of 5, 10, 20, and 50 years were designed, with a high temperature hazard index calculated by integrating two differen- tially-weighted extreme temperature indices （maximum temperature and high temperature days）. To perform the exposure analysis, a land use map was employed to determine the spatial distribution of susceptible human activities under the different scenarios. The results indicate that there are two heat-prone regions and a sub-hotspot occupying a relatively small land area. However, the societal and economic consequences of such an environmental im- pact upon the North China Plain and middle/lower Yangtze River Basin would be substantial due to the concentration of human activities in these areas.

Hazard Analysis on One-Room Building Fires

First, a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (shortly called RSET) in a one-room building fire is proposed and a model for predicting the death number caused by the fire is established in this paper. Then, numerical simulations are performed, and the following laws are discovered: (1) At the beginning of the fire, the smoke layer falls slowly; as the fire develops, it falls rapidly. (2) The hypotheses on the fire source, the combustion properties of the combustibles, and the width of the exit and the person number in the room are important factors which affect the death number in the fire.

Integrating image processing and deep learning for effective analysis and classification of dust pollution in mining processes

A comprehensive evaluation method is proposed to analyze dust pollution generated in the production process of mines.The method employs an optimized image-processing and deep learning framework to characterize the gray and fractal features in dust images.The research reveals both linear and logarithmic correlations between the gray features,fractal dimension,and dust mass,while employing Chauvenel criteria and arithmetic averaging to minimize data discreteness.An integrated hazardous index is developed,including a logarithmic correlation between the index and dust mass,and a four-category dataset is subsequently prepared for the deep learning framework.Based on the range of the hazardous index,the dust images are divided into four categories.Subsequently,a dust risk classifcation system is established using the deep learning model,which exhibits a high degree of performance after the training process.Notably,the model achieves a testing accuracy of 95.3%,indicating its efectiveness in classifying diferent levels of dust pollution,and the precision,recall,and F1-score of the system confrm its reliability in analyzing dust pollution.Overall,the proposed method provides a reliable and efcient way to monitor and analyze dust pollution in mines.

Progresses in geology and hazards analysis of Tianchi Volcano

A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.

Myths about Earthquakes:Quo vadis?

We are living in a world of numbers and calculations with enormous amount of pretty fast user-friendly software ready for an automatic output that may lead to a discovery or,alternatively,mislead to a deceptive conclusion,erroneous claims and predictions.As a matter of fact,nowadays,Science can disclose Natural Hazards,assess Risks,and deliver the state-of-the-art Knowledge of looming disaster in advance catastrophes along with useful Recommendations on the level of risks for decision making regarding engineering design,insurance,and emergency management.

Performance-based system seismic assessment for long-span suspension bridges under two-level seismic hazard

Since there are few studies on the performance-based seismic evaluation of the long-span suspension bridge system under two-level earthquake hazard in Chinese code,the developed procedure of this study can be regarded as a general program to assess the seismic performance of the overall system for long-span suspension bridges.In the procedure,the probabilistic seismic demand models of multiple bridge components were developed by nonlinear time-history analyses incorporating the related uncertainties,and the component-level fragility curves were calculated by the reasonable definition of limit states of the corresponding components in combination with seismic hazard analysis.The bridge repair cost ratios used to evaluate the system seismic performance were derived through the performance-based methodology and the damage probability of critical components.Furthermore,the repair cost ratios of the overall bridge system that was retrofitted with fluid viscous dampers for the main bridge and changed restraint systems for the approach bridges were compared.The results show that peak ground velocity and peak ground acceleration can be selected as the optimal intensity measurements of long-span suspension bridges using the TOPSIS(technique for order preference by similarity to an ideal solution).The bridge repair cost ratios can serve as accurate evaluation indicators to provide an efficient evaluation of retrofit measures.The seismic evaluation of long-span bridges is misled when ignoring the interaction of adjacent structures.However,the repair cost ratios of a bridge system that has optimum seismic performance are less sensitive to the relative importance of adjacent structures.

GIS applications in typhoon simulation and Hazard assessment

GIS technology provides a powenful tool for disaster hazard assessment and mitigation. A GIS based system is developed for typhoon data management and analysis, typhoon simulation and hazard assessment for southeast coast of China in this paper. A typhoon database by Microsoft Access is designed. Data manipulation and analysis, typhoon simulation and hazard assessment, and visualization of results are implemented on GIS platform. This GIS-based typhoon database and analysis system greatly facilitates typhoon hazard assessment.

Inferring seismic hazard in Sichuan-Yunnan region of China based on the modern earthquake catalogue (1980-2019)

Based on the modern earthquake catalogue,the incomplete centroidal voronoi tessellation(ICVT)method was used in this study to estimate the seismic hazard in Sichuan-Yunnan region of China.We calculated spatial distributions of the total seismic hazard and background seismic hazard in this area.The Bayesian delaunay tessellation smoothing method put forward by Ogata was used to calculate the spatial distributions of b-value.The results show that seismic hazards in Sichuan-Yunan region are high,and areas with relatively high hazard values are distributed along the main faults,while seismic hazards in Sichuan basin are relatively low.

Hazard identification and control in the pre-blasting process

Major mineral hazard identifications should consider perilous types of fatal accidents in collieries from its definition, and then set existent hazardous objects and their relevant amount as referenced factors. Eliminating hazards in systems and decreasing risks are their essential purposes with help of hazard identification, risk evaluation and management. By pre-control on major hazards, fatal accidents are avoided, stuffs＇ safety and healthy are protected, levels of safe management are enhanced, and perpetual systems are built up finally. However, choosing the proper identification and evaluation is a problem all along. Based on specific condition in Jiangou Coal Mine, method of LEC was applied for hazard identification and evaluation in the pre-blasting process within horizontal section top-coal mechanized caving of steep seams. And control measures to of each hazard were put forward. The identification method combining qualitative and quantitative analysis. So, it is practical and operable for the method to develop the given scientific research and has a distinctive impact on high efficiency and safety products for pre-blasting in horizontal section top-coal mechanized caving of steep seams.

Assessment of seismic hazard of roller compacted concrete dam site in Gilgit-Baltistan of northern Pakistan

The proposed site of the Diamer Bhasha Dam in northern Pakistan is situated in an active tectonic zone with intensive seismicity,which makes it necessary for seismic hazard analysis(SHA).Deterministic and probabilistic approaches have been used for SHA of the dam site.The Main Mantle Thrust(MMT),Main Karakaram Thrust(MKT),Raikot-Sassi Fault(RKSF)and Kohistan Fault(KF)have been considered as major seismic sources,all of which can create maximum ground shaking with maximum potential earthquake(MPE).Deterministically estimated MPE for magnitudes of 7.8,7.7,7.6,and 7.1 can be produced from MMT,MKT,RKSF and KF,respectively.The corresponding peak ground accelerations(PGA)of 0.07,0.11,0.13 and 0.05 g can also be generated from these earthquakes,respectively.The deterministic analysis predicts a so-called floating earthquake as a MPE of magnitude=7.1 as close as 10 km away from the site.The corresponding PGA was computed as 0.38 g for a maximum design earthquake at the project site.However,the probabilistic analysis revealed that the PGA with 50%probability of exceedance in 100 years is 0.18 g.Thus,this PGA value related to the operational basis earthquake(OBE)is suggested for the design of this project with shear wave velocity(V_(s30))equal to 760 m/s under dense soil and soft rock conditions.

Seismic hazard assessment of Tehran,Iran with emphasis on near-fault rupture directivity effects

Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis （PSHA） is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. （1997） model with broadband approach and Shahi and Baker （2011） model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.

Simplified Full Dynamic Analysis of a Railway Tunnel in Ethiopia

This paper presents an effective means of analyzing the safety of a tunnel under dynamic loading in areas with seismic records. A particular case of the railway tunnel in the earthquake-prone regions of the escarpment seismic zone of Ethiopia was the specific focus area of the research. Probabilistic seismic hazard analysis (PSHA) and deaggregation have been conducted to determine the design earthquake required as an input for the dynamic analysis. The PSHA performed by considering the operating design earthquake with conservative assumptions of the local geological features resulted in a peak ground acceleration of 0.36. Two pairs of design earthquake have been obtained from the deaggregation process, which were used to filter acceleration time histories for the selected design earthquake from the ground motion database of Pacific Earthquake Engineering Research Center. Finally, full dynamic analyses of the tunnel have been performed by applying the scaled acceleration time histories corresponding to the structure in the specific site. It was demonstrated how to prove the stability of the tunnel located in difficult ground conditions by performing plane strain analyses with the possible minimum computational efforts.