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91.
To evaluate techniques for assessing earthquake-triggeredlandslide hazard in the Southern Apennines (Italy), a GIS-based analysis was used to modelseismically induced slope deformations. Geological, geotechnical, geomorphological and seismologicaldata were integrated into a standard earthquake slope stability model. The model assessed thelandslide potential that existed during the 1980 Irpinian earthquake in the Upper Sele river Valley.The standard Newmark displacement analysis, widely used for predicting the location of shallowunstable slopes, does not take into account errors and/or uncertainties in the input parameters.Therefore, a probabilistic Newmark displacement analysis technique has been used. Probabilistictechniques allow, e.g., an estimation of the probability that a slope will exceed a certain criticalvalue of Newmark displacement. In our probabilistic method, a Monte-Carlo based simulation modelis used in conjunction with a GIS. The random variability of geotechnical data is modelled by probabilitydensity functions (pdfs), while for the seismic input three different regression laws wereconsidered. Input probability distributions are sampled and the resulting values input into empiricalrelations for estimating Newmark displacement. The outcome is a map in which to each siteis related a spatial probability distribution for the expected displacement in response to seismic loading.Results of the experiments show a high grade of uncertainty in the application of the Newmarkanalysis both for the deterministic and probabilistic approach in a complex geological setting suchas the high Sele valley, quite common in the Southern Apennines. They show a strong dependence onthe reliability of the spatial data used in input, so that, when the model is used at basin scale,results are strongly influenced by local environmental condition (e.g., topography, lithology, groundwatercondition) and decrease the model performance.  相似文献   
92.
赵慈平 《地震研究》2002,25(2):140-148
2001年云南澜沧5.0、施甸5.2,5.9,5.3、宁蒗5.8、楚雄5.3和江川5.1级地震前,云南49项水氡前兆中的一些台站出现突出的异常。研究发现,根据这些异常项的异常特征和空间分布特征及历史震例,可对这几次地震预报的三要素,尤其是地点和时间做出较好的判断。  相似文献   
93.
川滇地区地震(Ms≥5.0)破裂类型与前兆异常分布的关系   总被引:1,自引:0,他引:1  
对川滇地区 31次 (组 ) 5 .0级以上地震与余震次数的关系进行了统计 ,结合“强地震分为走滑型地震和断错型地震”的理论 ,确定了各次 (组 )地震的破裂类型。从物理机制上对地震破裂类型与震前前兆异常分布关系进行了讨论 ,由此进一步探讨了 5 .0级以上地震震后趋势预测  相似文献   
94.
This paper presents the results of a study undertaken todetermine the seismic hazard of Lebanon. The seismic hazard evaluation wasconducted using probabilistic methods of hazard analysis. Potential sourcesof seismic activities that affect Lebanon were identified and the earthquakerecurrence relationships of these sources were developed from instrumentalseismology data, historical records, and earlier studies undertaken toevaluate the seismic hazard of neighboring countries. The sensitivityof the results to different assumptions regarding the seismic sources in theLebanese segment and choice of the attenuation relationship wasevaluated. Maps of peak ground acceleration contours, based on 10percent of probability of exceedance in 50 years and 100 years time spans,were developed.  相似文献   
95.
Based on the fitting on paleoearthquake data of intra-plate regions in the northern part of Chi-na and giving a statistical model of time interdependence,the potential damage earthquakes in a definite future period and characteristics of present shocks along the Lingwu fault have been analyzed by using dangerous probability function and some new data concerned.We have in-ferred that the fault has entered a period that earthquakes will probably occur.There exists a potential danger that a strong earthquake with Ms7.0-7.5 will occur in 10-100a.  相似文献   
96.
XieLili 《中国地震研究》2002,16(3):275-282
This paper describes briefly the recent advances and acievements of the research projects conducted by the Institute of Engineering Mechanics(IEM) in the period of the Ninth Five-Year Plan(1995-2000) with the support of the China Seismological Bureau(CSB),These projects are related with key problems in the field of earthquake engineering.They are:development of the methods for determining earthquake resistant design load level,study on mechanisms of earthquake damage to buildings.development of new technology of base isolation,and study on earthquake damage prediction and seismic losss assessment methods.Through these studies,quite a number of problems have een solved and some of them have een applied in earthquake engineering design and practice.  相似文献   
97.
山西地电中短期前兆异常识别方法浅析   总被引:1,自引:0,他引:1  
用傅氏滑动法、动态距平法、速率法、均值法等对山西大同台、代县台、临汾台的地电异常进行了分析 ,对地电阻率异常的判定、预报方法效能进行了评价 ,对不同的台站 ,从正常的变化形态中找出了突出异常的有效方法 ,从中提取出因地壳应力变化引起的地震前兆异常 ,结果表明 ,5 .0级以上地震在Δ=15 0 km范围内有明显的中短期前兆异常  相似文献   
98.
各省地震局 95 - 0 1- 0 2地震信息网络项目采用的邮件系统是基于 IRIX 6 .5操作系统的Netscape Mail Server2 .0 ,由于其应用与管理有局限性 ,笔者进行了基于 NT系统的 ExchangeServer5 .0邮件系统的应用研究 ,详细论述了基于 Exchange Server5 .0的黑龙江省地震前兆信息网络邮件系统的安装及配置过程 ,得出该网络邮件系统有管理方便、功能强大的结论  相似文献   
99.
为了解决河南豫北地区地震的定位问题 ,对豫北台网内的 10个典型地震 ,使用了 7个地震台站的资料 ,用波速比求出横波速度 ;用和达定位法 (有的同时使用高桥法 )进行了精确定位 ,求出震源深度 ;测量了震中至各台的震中距 ,以此反算出了纵波速度。通过计算 ,确定出了较为适合河南豫北地震台网地区的波速。  相似文献   
100.
According to the principle of the eruption of debris flows, the new torrent classification techniques are brought forward. The torrent there can be divided into 4 types such as the debris flow torrent with high destructive strength, the debris flow torrent, high sand-carrying capacity flush flood torrent and common flush flood by the techniques. In this paper, the classification indices system and the quantitative rating methods are presented. Based on torrent classification, debris flow torrent hazard zone mapping techniques by which the debris flow disaster early-warning object can be ascertained accurately are identified. The key techniques of building the debris flow disaster neural network (NN)real time forecasting model are given detailed explanations in this paper, including the determination of neural node at the input layer, the output layer and the implicit layer, the construction of knowledge source and the initial weight value and so on. With this technique, the debris flow disaster real-time forecasting neural network model is built according to the rainfall features of the historical debris flow disasters, which includes multiple rain factors such as rainfall of the disaster day, the rainfall of 15 days before the disaster day, the maximal rate of rainfall in one hour and ten minutes. It can forecast the probability, critical rainfall of eruption of the debris flows, through the real-time rainfall monitoring or weather forecasting. Based on the torrent classification and hazard zone mapping, combined with rainfall monitoring in the rainy season and real-time forecasting models, the debris flow disaster early-warning system is built. In this system, the GIS technique, the advanced international software and hardware are applied, which makes the system′s performance steady with good expansibility. The system is a visual information system that serves management and decision-making, which can facilitate timely inspect of the variation of the torrent type and hazardous zone, the torrent management, the early-warning of disasters and the disaster reduction and prevention.  相似文献   
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