云南活断裂分布对于震害面积影响的模糊定量研究

本文以云南地震地质为背景,定义出活动断裂交汇程度作为影响地震震害面积的定量指标,并应用模糊信息处理方法,分析了云南39个历史地震资料,推导出震级、震源深度、断裂交汇程度与震害面积之间的模糊关系,然后研究震源深度为15,25公里时的震级、震害面积关系。文章结论指出:在活断裂密集的高烈度区,断裂分布情况具有影响震害面积的重要作用。此项研究结果,对高烈度区的工程抗震设防范围考虑,具有一定指导意义。

A FUZZY QUANTITATIVE STUDY ON THE EFFECT OF ACTIVE FAULT DISTRIBUTION ON ISOSEISMAL AREA IN YUNNAN

This paper first defines a parameter named“Degrees of Active Fault Intersection”(D.F.I.)as a quantitative measure of active fault distribution based on seismotectonic structure of Yunnan province.Using the method of fuzzy information analysis,39 earthquake records of Yunnan are employed to figure out the fuzzy relation between the magnitude,focal depths, D.F.I.,and isoseismal area.The principle of fuzzy inference is applied to evaluate the variation of isoseismal area VS.the change of magnitude when the focal depths are fixed at 15 and 25 kms respectively. The paper concludes that in areas of high seismic intensity and dense active faults,the extent of earthquake disaster is mainly controlled by fault distribution rather than seismic magnitude,which is significant to the disaster mitigation planning.