Research on Earthquakes in Cities of China     

Shi Zhenliang  Cao Xuefeng  Yan Xiujie 《中国地震研究》2003,17(3):248-255

In this paper, we briefly describe the general destruction caused by historic earthquakes in major cities of China, preliminarily analyze the heaviness and widespread occurrence of earthquakes in cities of China, and suggest that research on scenario earthquakes in cities should be developed as a part urban disaster reduction research.  相似文献   

Spatial probabilistic modeling of slope failure using an integrated GIS Monte Carlo simulation approach   总被引：4，自引：0，他引：4  

G. Zhou  T. Esaki  Y. Mitani  M. Xie  J. Mori 《Engineering Geology》2003,68(3-4):373-386

Spatial probabilistic modeling of slope failure using a combined Geographic Information System (GIS), infinite-slope stability model and Monte Carlo simulation approach is proposed and applied in the landslide-prone area of Sasebo city, southern Japan. A digital elevation model (DEM) for the study area has been created at a scale of 1/2500. Calculated results of slope angle and slope aspect derived from the DEM are discussed. Through the spatial interpolation of the identified stream network, the thickness distribution of the colluvium above Tertiary strata is determined with precision. Finally, by integrating an infinite-slope stability model and Monte Carlo simulation with GIS, and applying spatial processing, a slope failure probability distribution map is obtained for the case of both low and high water levels.  相似文献   

Process of Housing Damage Assessment: The 1995 Hanshin-Awaji Earthquake Disaster Case     

Horie  Kei  Maki  Norio  Kohiyama  Masayuki  Lu  Hengjian  Tanaka  Satoshi  Hashitera  Shin  Shigekawa  Kishie  Hayashi  Haruo 《Natural Hazards》2003,29(3):341-370

Rebuilding of victims' livelihoods was a crucial issue in the restoration process in the1995 Hanshin-Awaji Earthquake Disaster. Housing damage assessment influencedmost of the rebuilding of the livelihood in the long term, because the Victim Certificatesissued by the local governments based on the results of the Housing damage assessmentwas required to receive most of the individual assistance measures. In the process ofHousing damage assessment, many complex problems arose, leading to extensivework on the part of the disaster responders. Consequently, a considerable number ofvictims were dissatisfied with the assessment and applied for a resurvey. Due to a floodof requests for resurvey, disaster responders had to work on damage assessment, leavingrelief activities aside.In order to facilitate Housing damage assessment, this paper discusses thefollowing five points: (1) the processes and the problems of assessments performedin the Hanshin-Awaji Earthquake Disaster, (2) the changes in the nature of informationneeded by the victims, (3) the improvements over the present damage assessment, (4)the housing situation in Japan, and (5) the international situation on damage assessment.It is obvious from the results that a poor damage assessment system and the size ofthe disaster produced a very large work load. Differences in appreciation among theinvestigators also contributed to unfair assessments and led to the victims beingincreasingly dissatisfied by the survey results. Finally, a design concept for acomprehensive damage assessment system, which has been derived from theabove five points, is proposed for post-disaster management.  相似文献   

Reliability based risk index for the design of reinforced earth structures   总被引：1，自引：0，他引：1  

Adnan A. Basma  Samer A. Barakat  Maher T. Omar 《Geotechnical and Geological Engineering》2003,21(3):225-242

The design methods currently used for earth reinforcement are mostly based on deterministic properties of both the soil and the construction materials used. Nowadays, however, the general trend is designing at a specific degree of reliability. This is even more true where the raw data such as soil properties exhibit significant variation. Deterministic solutions, in this case, may not suffice. Therefore, this paper will attempt to use probabilistic formulations thereby modifying the existing design procedure of reinforced earth retaining walls to account for uncertainties and variabilities. Through a first order Taylor's series expansion about the mean, the mean and variance of the strip reinforcing components, namely width and length, are derived in terms of the variations in the soil properties. Design charts that enable estimation of both mean and variance are developed to avoid extensive partial differentiation involved in the computations. Using appropriate probability distributions along with the mean and variance, the final design outputs are determined for a selected failure probability by introducing what is refered to as 'risk index'. The results indicate that the risk index increases with an increase in the coefficient of variations and a decrease in failure probability. Furthermore, it is shown that in some cases, depending on the variabilities of the soil properties, the classical design technique produced a relatively high failure probability. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Microearthquakes and faulting in the southern Okinawa Trough     

Mamoru Nakamura  Hiroshi Katao 《Tectonophysics》2003,372(3-4):167-177

Southern Okinawa Trough represents an early stage of back-arc rifting and is characterized by normal faulting and microearthquakes. Earthquake distribution and deep structure of fault was investigated to clarify active rifting in the southern Okinawa Trough, where two parallel grabens are located. A network of ocean bottom seismometers (OBSs) that displayed the hypocenters of 105 earthquakes were observed for a period of 4 days in southern-graben (SG). Most of the microearthquakes occurred in a cluster about 7 km wide, which on a cross-section striking N45°E dips 48° to the southwest. Relocated hypocenters, which are recorded by a local seismic network, show scattered distribution around the southern-graben. There are no remarkable surface faults in the southern-graben. On the other hand, the recalculation of hypocenter locations of 1996 earthquakes swarm recorded by a local seismic network suggests that the swarm is associated with normal faulting on the southern side of northern-graben (NG). Thus, the undeveloped southern-graben is located to the south of the developed northern-graben. Southward migration of rifting, which may be caused by migration of volcanism, could thus be occurring in the southern Okinawa Trough. The extension rate computed for the southern Okinawa Trough from the fault model of the northern-graben is 4.6 cm/year, which is 59–102% of the extension rate (GPS measurements). This result indicates that the majority of extensional deformation is concentrated within the center of the northern-graben in the Okinawa Trough.  相似文献   

Theoretical Study on Stochastic Modeling of Combined Gravity-Magnetic-Electric-Seismic Inversion and Its Application     

YanHanjie YanHong LiYunping ZhangXiaofeng 《中国地质大学学报(英文版)》2003,14(3):227-233

As gravity field,magnetic field,electric field and seismic wave field are all physical fields,their object function,reverse function and compound function are certainly infinite contiuously differentiable func-tions which can be expanded into Taylor (Fourier) series within domain of definition and be further reduced in-to solving stochastic distribution function of series and statistic inference of optimal approximation,This is the basis of combined gravity-magnetic-electric-seismic inversion built on the basis of separation of field and source gravity-magnetic difference-value(D-value)trend surface,taking distribution-independent fault sys-tem as its unit,depths of seismic and electric interfaces of interests as its corresponding bivariate compound re-verse function of gravity-magnetic anomalies and using high order polynomial(high order trigonometric func-tion)approximating to its series distribution,The difference from current dominant inversion techniques is that,first,it does not respectively create gravity-seismic,magnetic-seismic deterministic inversion model from theoretical model,but combines gravity-magnetic-electric-seismic stochastic inversion model from stochastic model;second,after the concept of equivalent geological body being introduced,using feature of independent variable of gravity-magnetic field functions,taking density and susceptibility related to gravity-magnetic func-tion as default parameters of model,the deterministic model is established owing to better solution to the con-tradictioc of difficulty in identifying strata and less test analytical data for density and susceptibility in newly explored area;third,under assumption of independent parent distribution,a real modeling by strata,the prob-lem of difficult plane closure arising in profile modeling is avoided,This technology has richer and more detailed fault and strata information than sparse pattern seismic data in newly explored area,successfully inverses and plots structural map of Indosinian discontinuty in Hefei basin with combined gravity-magnetic-electric-seismic inversion,With development of high precision gravity-magnetic and overall geophysical technology,it is certain for introducing new methods of stochastic modeling and computational intelligence and promoting the develop-ment of combined gravity-magnetic-electric-seismic inversion to open a new substantial and promoting the develop-ment of combined gravity-magnetic-electric-seismic inversion to open a new substantial path.  相似文献   

用非线性多因子动态组合方法作降水概率预报   总被引：1，自引：0，他引：1       下载免费PDF全文

邵明轩刘凤辉  程维中魏建明窦以文  陈大刚 《气象科技》2003,31(4):206-210

将逐时段定点降水预报这个以往一般作为非连续量处理的预报问题转化为对一个连续的降水可能函数的预报问题。降水可能函数为一由实况值确定的函数。因为现在模式变化较快，且许多因子和降水可能函数为非线性关系，文章采用一种新的非线性多因子动态组合方法，通过对降水可能函数的预报，作客观分站降水概率预报。  相似文献   

地震前兆信息网安全管理的几个问题     

周浩  张凤鸣  于爱礼 《东北地震研究》2003,19(4):56-60

从主机系统安全、服务软件配置、网络系统安全、木马和病毒防范以及安全管理制度等几个方面进行了探讨，总结了基于NT技术的前兆网络安全防范问题，给出了加强前兆网络安全的一些措施和建议。  相似文献   

地震预测的构造物理模型研究     

邓志辉王绳祖  黄秀铭周本刚 徐好民 《地震》2003,23(2):21-28

在系统收集和分析中国大陆的活动构造、地震活动和地球物理场资料的基础上，初步圈定出769个构造物理潜在震源，并对其中477个位于主要强震区、带内的潜在震源进行了空间几何定量描述和基本震源参数的系统分析，在GIS平台上开发了分析系统，逐一计算了每一潜在震源的十年发震概率，圈定了1999～2008年的强震危险区，根据发震概率的大小对危险区的危险性进行分类。近几年发生的强震与预测结果的对比检验结果表明，用构造物理模型确定的十年地震危险区具有较好的预测效果。  相似文献   

地图手工数字化对点误差的统计分布     

史文中  刘文宝 《武汉大学学报(信息科学版)》1997,(1)

定义了对点误差，导出了统计分布密度和分布函数，给出了矩母函数、特征函数和数字特征，以及对点误差及其投影分量和标准化分布  相似文献