地震损失的空间相关性及其对震害损失估计的影响

在地震危险性分析或者地震损失分布评估中,需要考虑地震损失的空间相关性的影响。目前对地震损失空间相关性的研究,主要是基于经验或半经验的方法,没有经过实际地震损失分布的验证。本文基于2011年东日本大地震收集到的55万条建筑物破坏的详细数据得出了基于实际震害的地震损失随距离关系变化的空间相关性衰减规律,给出了一个基于实际数据的拟合公式,并将其应用于最新开发的基于高精度模拟的巨灾风险分析中。利用北京地区多个地震为算例,研究了实现空间相关性模拟的样本精度问题,并且给出了不同空间相关系数对地震损失分布的影响,从而能为未来的防震减灾工作提供更好的地震损失估计结果。     

基于重复地震的地壳介质参数分析软件

随着数字地震学的快速发展,重复地震在地震学的研究中显得越来越重要。本文首先介绍了重复地震的定义和识别方法,然后基于此研制了重复地震识别与分析软件,最后给出了重复地震在地震预测中的一个实际应用例子。结果表明基于该软件工具可充分利用数字地震波形开展相对高精度的地壳介质动态变化分析。     

基于MATLAB工具箱的地震预测模型

地震分析和预测对未来地震趋势有一定预见性。本文建立了基于MATLAB工具箱的地震预测模型,通过建模、局限性分析,认为多元线性和非线性回归方法不适合地震预测,基于BP神经网络的方法在地震预报中有一定应用价值。     

基于GIS的中国地震危险性模式研究

从与历史地震数据的时间衔接考虑,合理选择初始地震危险性模式。借鉴美国地震危险性图编制的思路,并基于GIS的思想和技术,使用历史地震数对初始模式进行多次叠加改造,获得当今中国地震危险性模式。与实际地震灾害的对照结果,验证了该方法的有效性。可见,基于GIS的中国地震危险性模式研究具有一定的现实意义。     

基于GIS的地震专题图制图中的功能开发

在探索基于GIS的地震专题制图自动化中,开发建立了基于TrueType技术的地震专题符号库,提出了地震制图自动化中线型和面型的解决方法,利用二次开发弥补了MapInfo软件在标注功能上的不足,基本满足了地震专题制图的要求。     

辽宁省地震易发区地震危险性研究

盘锦、海城、营口地区是辽宁省内地震活动性最强、地震危险性最高的地区。该地区开展了大量重点工程地震安全性评价、区域性地震区划和地震小区划工作，但尚未开展基于场地条件的区域尺度地震危险性研究。独有的沉积特点使该地区场地条件较复杂，因此在地震危险性概率分析中考虑场地条件是必要的。本文基于新一代中国地震动参数区划图基本原理和技术原则，结合盘锦、海城、营口地区场地条件特征，采用基于地形坡度的方法对场地条件进行分类，确定场地地震动影响系数，给出该地区基于区域场地条件的地震危险性分布，相关研究结果可为地震风险评估和防震减灾规划提供参考。     

设定地震及其烈度影响判别

设定地震常用于震害预测、地震小区划和重大工程选址,烈度衰减模型反映了地震引起的地面震动及其影响的强弱程度分布。设定地震包括确定性和非确定性设定两种方法,确定性方法基于构造或历史地震,非确定性方法是基于概率危险性方法,用于估计区域或城市未来可能遭遇的地震危险。缺失等震线或震害记载不详的历史地震和概率设定地震都不能确切地反映地震破坏影响,借助于烈度衰减关系模型和GIS,可直观地判别其影响分布情况,便于设定地震的取舍。     

基于云计算的地震预警网络系统的设计与实现

传统基于数据融合的地震预警网络系统在对地震进行预警时,需要分析大量的地震数据,存在地震预警偏差高和动态监测性能差的弊端,因此本论述设计了基于云计算的地震预警网络系统,采用SaaS技术设计系统总体架构,通过核心是STM32F103RET6单片机的地震监测传感器模块,采集地震波信息。系统采用多地区地震数据并发过滤接收技术,对海量数据进行及时有效的接收和处理。系统实现过程中设计了系统的软件架构,基于Web页面的地震震波仿真显示模型,用浏览器中的High Chart JS软件模拟显示地震波形,给出了系统软件进行地震事件触发检测管理线程流程以及系统台站误触发判断实现流程。实验结果说明,所设计系统能够准确的对地震发生作出预警,动态监测性能强。     

基于NetSeis/IP协议的地震信息自动化发布

地震信息是地震发生的时间、震级、震中参考地名等信息。地震信息的快速准确发布,可以进一步提高地震应急救援反应能力,满足广大社会公众对地震信息的了解。地震信息的快速发布和获取能有效提高防震减灾效果,介绍基于NetSeis/IP协议地震信息自动发布方法及地震信息自动发布软件Autosms,对系统时效性进行测试,结果表明,基于NetSeis/IP协议的信息发布软件延时小,发送速度快,尤其大批量短信发布,时效性更高,可实现震情的快速发布。     

基于网络技术的测震系统在市县地震部门的应用

介绍了基于网络技术的测震系统在市县地震部门的应用,从一个侧面反映出安徽＂十五＂数字测震台网建设的显著成效。基于网络技术的测震系统成功推广,不仅扩大了市县地震部门的业务范围,完善其监测预报体系建设,而且提高了市县地震部门的地震监测能力和地震研究水平,提升了市县地震部门在各级政府的影响力和社会显示度。     

Models for extremes using the extended three-parameter Burr XII system with application to flood frequency analysis / Modèles d’extrêmes utilisant le système Burr XII étendu à trois paramètres et application à l’analyse fréquentielle des crues

Abstract

Abstract A new theoretically-based distribution in frequency analysis is proposed. The extended three-parameter Burr XII distribution includes the generalized Pareto distribution, which is used to model the exceedences over threshold; log-logistic distribution, which is also advocated in flood frequency analysis; and Weibull distribution, which is a part of the generalized extreme value distribution used to model annual maxima as special cases. The extended Burr distribution is flexible to approximate extreme value distribution. Note that both the generalized Pareto and generalized extreme value distributions are limiting results in modelling the exceedences over threshold and block extremes, respectively. From a modelling perspective, generalization might be necessary in order to obtain a better fit. The extended three-parameter Burr XII distribution is therefore a meaningful candidate distribution in the frequency analysis. Maximum likelihood estimation for this distribution is investigated in the paper. The use of the extended three-parameter Burr XII distribution is demonstrated using data from China.     

新疆人口分布和地震分布的关系初探

本文在分析新疆人口分布和强地震地理分布特点的基础上,得出人口在地震活动带上相对集中的结论。并根据新疆构造地貌特点和气候水文条件,对这一现象的产生作了初步探讨。     

Maximum product of spacings estimators for the generalized pareto and log-logistic distributions

The maximum product of spacings (MPS) method is discussed from the standpoint of information theory. MPS parameter and quantile estimates for the generalized Pareto distribution and the two parameter log-logistic distribution are compared with the maximum likelihood(ML) and probability weighted moment (PWM) estimates.     

The first and the second e of the extreme value distribution,EV1

In the peak over threshold model resulting in the Extreme-value distribution, type I, (EV1) the firste of the distribution function is based on the Poisson number of exceedances, and the seconde arises from the Exponentially distributed magnitudes.This paper, on the one hand, generalises the Poisson model to the (positive and negative) Binomial distribution, and, on the other hand, the Exponential distribution is generalised to the Generalised Pareto distribution. Lack of fit with respect to the Poisson and Exponential distribution is measured by statistics derived from those which would be locally most powerful if the estimates of the location and scale parameter were equal to the true parameter values. Ways of combining both statistics are discussed.     

极光区离子分布函数视线方向上的解析解及其饱和现象

以弛豫碰撞模式下Boltzmann方程的解为基础，从极光区视线方向上离子的非Maxwell一维速度分布函数的Raman等人的积分解出发，导出了一维速度分布函数的解析形式解，给出了它的一些特性，并研究了该分布函数随电场增强而出现的饱和现象，给出了物理解释，计算了几种情况下的饱和电场值．     

The generalized Pareto sum

The generalized Pareto distribution has received much popularity as models for extreme events in hydrological sciences. In this note, the important problem of the sum of two independent generalized Pareto random variables is considered. Exact analytical expressions for the probability distribution of the sum are derived and a detailed application to drought data from Nebraska is provided. Copyright © 2007 John Wiley & Sons, Ltd.     

Approximating the Distribution of Pareto Sums

Heavy tailed random variables (rvs) have proven to be an essential element in modeling a wide variety of natural and human-induced processes, and the sums of heavy tailed rvs represent a particularly important construction in such models. Oriented toward both geophysical and statistical audiences, this paper discusses the appearance of the Pareto law in seismology and addresses the problem of the statistical approximation for the sums of independent rvs with common Pareto distribution F(x)=1 – x^– for 1/2 < < 2. Such variables have infinite second moment which prevents one from using the Central Limit Theorem to solve the problem. This paper presents five approximation techniques for the Pareto sums and discusses their respective accuracy. The main focus is on the median and the upper and lower quantiles of the sums distribution. Two of the proposed approximations are based on the Generalized Central Limit Theorem, which establishes the general limit for the sums of independent identically distributed rvs in terms of stable distributions; these approximations work well for large numbers of summands. Another approximation, which replaces the sum with its maximal summand, has less than 10% relative error for the upper quantiles when < 1. A more elaborate approach considers the two largest observations separately from the rest of the observations, and yields a relative error under 1% for the upper quantiles and less than 5% for the median. The last approximation is specially tailored for the lower quantiles, and involves reducing the non-Gaussian problem to its Gaussian equivalent; it too yields errors less than 1%. Approximation of the observed cumulative seismic moment in California illustrates developed methods.     

两种新参数在银川—河套和祁连山—六盘山地震带地震预报中的应用研究

采用极值理论求得岗贝尔分布b值,可以克服目前广泛使用的求b值的方法对资料要求高的弱点。根据中强地震发生前小震出现偏离泊松分布的现象,构造泊松分布符合度Yn值。将这两种参数具体应用于银川-河套地震带和祁连山-六盘山地震带进行预测检验。结果表明在两个区域岗贝尔分布b值和泊松分布符合度Yn值对中强地震映震效果均较好。     

A simple model for spatial rainfall fields

Spatial rainfall amounts accumulated over short to medium periods of time, say a few days, tend to have a probabilistic structure with very distinctive features. Some of these that are specially relevant for the purpose of spatial modeling are the presence of mixed sampling distributions, right skewed distributions conditional on rainfall occurrence, and a complex spatial association structure. The goal of this work is to construct a family for the bivariate distributions of spatial rainfall fields that incorporates these distinctive features. It is based on the separate modeling of spatial occurrence of rainfall and the spatial distribution of positive rainfalls. The main properties of the bivariate distributions are derived, and some properties of the random field realizations are illustrated through simulation. Some limitations of the proposed model are also discussed.     

Study of the Non-Uniform Distribution of Earthquake Risk Within Potential Sources

Potential sources are aggregates of probable future epicenters.In this area,for source models currently,in common use for seismic risk analysis in China,the mean area of each potential source is about 3000-4000 km2.It is assumed that seismic risk has a uniform distribution within the range of each potential source,but studies have shown that the uniform distribution model to a large extent may give an underestimation of the seismic risk.In this paper,the relative distribution of historical epicenters in space within potential sources is discussed,a method is proposed to quantitatively describe the non-uniform distribution of strong earthquakes within potential sources,and some preliminary results are given.By using the results of this paper,seismic risk analysis and seismic zonation can be made more scientific and more reasonable.