基于双损失指标的地震灾度模型

将地震灾害等级划分为巨灾、大灾、中灾、小灾、微灾等5个等级,给出每个灾害等级的灾度下限D_i。选取地震灾害的死亡人数和直接经济损失相对值作为计算灾度的2个指标,采用“直接经济损失/年人均GDP”处理方法对直接经济损失进行无量纲化,为不同年代、不同地区的地震灾害灾度大小对比奠定基础。采用椭圆方程作为相邻灾害等级之间的分界线,给出相应参数以确定分界线方程表达式,在此基础上给出合理的地震灾度模型计算公式。利用假设值和中国部分实际地震灾例验证了本文给出的地震灾度模型的科学性、适用性和可比性,给出的地震灾害灾度计算模型可以推广到其他灾害。最后,比较唐山地震和汶川地震的计算灾度值,认为唐山地震的灾度大于汶川地震,并对这一结果的合理性进行了讨论。

Seismic Disaster Magnitude Model Based on Double Loss Indicators

In this paper,earthquake disaster degree is divided into five classes:catastrophe,major disaster,medium disaster,small disaster and micro disaster,in which the lower limit Di of disaster magnitude of each disaster class is given. The death toll of earthquake disaster and the relative value of direct economic loss are selected as two indicators to calculate the disaster magnitude. By "(direct economic loss)/(annual per capita GDP)" processing method we adopted the dimensionless direct economic loss,in order to lay a foundation for the comparison of earthquake disaster severity in different years and regions. The elliptic equation is used as the boundary between adjacent disaster classes,and the corresponding parameters are given to determine the expression of the boundary equation. On this basis,strict mathematical derivation is carried out,and a reasonable calculation formula of seismic disaster magnitude model is given. The scientific applicability and comparability of the seismic disaster magnitude model given in this paper,which are verified by hypothetical values and some actual seismic disaster examples in China. The calculation model of earthquake disaster magnitude can be extended to other disasters. By comparing the calculated disaster magnitude values of Tangshan earthquake and Wenchuan earthquake,we find that the disaster magnitude of Tangshan earthquake is greater than that of Wenchuan earthquake,and the rationality of this result is discussed.