多维损失指标的灾度计算模型

Disaster magnitude calculation model of multi-dimensional loss indicators

科学合理的灾害等级定量评定模型,有利于合理划分地震等自然灾害的影响程度等级和灾害分级管理。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,简化和统一不同年代、不同地区的直接经济损失相对值。在已有灾度计算模型的基础上,以地震灾害为例,定义了灾害等级及相应的灾度值下限,考虑直接经济损失相对值、死亡人数、受伤人数等三个损失指标,以椭球面为灾度等值面,构建了三维灾度计算模型。本模型通过严格的数学推导得出,模型本身对所用的各损失指标进行了无量纲化处理,能定量比较不同发生时间和地点的地震灾害损失程度,可推广到其他灾害的灾度值计算及等级评定。三维灾度模型能方便地扩展到更高维度的灾度模型上去,而灾害分级与灾度分级值D i保持不变。通过部分中国实际地震灾例的灾度计算和灾害分级,检验了模型的科学性和适用性。初步讨论和分析了一维退化灾度计算模型:将人口损失粗略折算为当量经济损失,计算结果表明,即使采用较高的赔偿标准,地震灾害导致人口损失的折算经济当量占总经济损失当量的份额是比较小的。

A scientific and reasonable quantitative assessment model of disaster grade is conducive to the rational classification of the impact of earthquakes and other natural disasters and the hierarchical management of disasters.The“direct economic loss/annual per capital GDP”treatment method is adopted to nondimensionalize the direct economic loss,in order to simplify and unify the relative value of direct economic loss in different years and regions.On the basis of the existing disaster magnitude calculation model,taking the earthquake disaster as an example,the disaster grade and the corresponding lower limit value of disaster magnitude are defined.Considering the relative value of direct economic loss,the number of deaths and the number of injuries,a three-dimensional disaster magnitude calculation model is developed with the ellipsoid as the isosurface of disaster magnitude.This model is derived through strict mathematical derivation.The model itself carries out dimensionless treatment on all loss indicators used,which can quantitatively compare the loss of earthquake disasters at different times and places,and can be extended to the disaster magnitude and grade evaluation of other disasters.The three-dimensional disaster magnitude model can be easily extended to a higher dimensional disaster magnitude model,while the disaster classification and corresponding lower limit of disaster magnitude D i remain unchanged.The scientificity and applicability of the model are tested through the calculation of disaster magnitude and grade classification of some actual earthquake disasters in China.The calculation model of one-dimensional degradation disaster magnitude is preliminarily discussed and analyzed that the population loss is roughly converted into equivalent economic loss.The calculation results show that even with a higher compensation standard,the economic equivalent of population loss caused by seismic disasters accounts for a relatively small share of the total economic loss equivalent.