基于离散灾情信息的地震烈度分布快速判定方法研究*

根据历次破坏性地震实际灾情反馈特点的分析总结,结合地震灾害的演变机理和分布特点,本文尝试利用3种基于离散灾情信息点推漫灾情分布面的方法在不同灾情获取阶段快速判定地震烈度分布。从计算原理、数据基础、方法特点和判定结果看,三种方法具有不同的应用场景。泰森多边形判定法简单、易行,可用于震后初期灾情量较少时使用,判定结果较粗糙,必须再结合震源特性、破裂过程以及地形地貌条件等对震害分布的影响进行综合判定后才能得出相对合理的震害分布预判结果;克里金插值判定法是一种基于地理统计方法的空间插值方法,对数据分布有明确要求,其判定结果对灾区范围整体把握较好,可用于已经获取一定量灾情信息但灾区情况尚未明朗时使用,其插值结果再结合地震破裂过程以及震后余震分布信息综合调整后,可作为灾害评估修正和应急决策参考;标准差距离椭圆拟合方法是基于地震烈度分布呈椭圆形的假设提出的,对数据的敏感度较高,可用于对可信度较高的或由专业途径上报的灾情信息进行拟合,其结果可作为现场灾害调查和确定最终烈度分布的参考。

Fast Determination Method of Seismic Intensity Distribution Based on Discrete Disaster Information

According to analysis of disaster information feedbacks from previous destructive earthquakes,and combined with evolution mechanism and distribution characteristics of earthquake disasters,we put forward three methods for fast assessing seismic intensity distribution based on discrete disaster information.In addition,considering the calculation principle,data base,characteristics and determination results,the three methods could be applied in different scenarios.The simple and easy Tyson-polygon method is can be used during the initial period of earthquake emergency in which little disaster information is acquired roughly,and needs to be combined with influences of earthquake source,rupture process and terrain conditions on damage distribution for obtaining relatively reasonable disaster distribution assessment result.The Kriging-interpolation method,which is a spatial interpolation method based on geo-statistics,has strict requirements on data distribution, and its result is better in assessing the disaster scope and can be used as a reference of disaster assessment correction and emergency decision-making after comprehensive adjusting with seismic rupture process and the earthquake aftershock distribution when a certain amount of disaster information is acquired whereas the disaster situation is not clear.The ellipse fitting by distance standard deviation method is based on the hypothesis that seismic intensity distribution is oval,sensitive to data and can be used for fitting disaster information with high credibility or reported from professional source,and its result can be used as a reference of disaster field investigation and evaluation of earthquake intensity distribution.