Materials of the International Conference
50th Anniversary of the International Geophysical Year
and Electronic Geophysical Year

16-19 September 2007 • Suzdal, Russia

Data on losses from natural disasters. Tendencies of change in the recent world

M. V. Rodkin1 and V. F. Pisarenko2

1Geophysical Centre, Russian Academy of Sciences, Moscow, Russia

2International Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Moscow, Russia

Abstract

The cumulative numbers of victims from natural disasters (earthquakes, floods, hurricanes etc.) as well as the cumulative economical losses from disasters have a definite tendency to a non-linear increase with time. This effect is commonly believed to be related with the population growth, increase in a number of potentially dangerous technologies, and to environment degradation. Being extrapolated this tendency leads to the conclusion that in the middle of this century all economic growth will be devoured by the increase of loss values from disasters. Such prognosis evidently interferes with the idea of the sustainable development of society. However, an alternative model of the effect of loss growth can be suggested. Thus, for the case of earthquakes, the non-linear growth of cumulative losses is shown to be connected with the "heavy tail" in the loss distribution; change in occurrence rate of disasters is of a minor importance. Actually, the distribution function F(x) of losses from earthquakes has a "heavy tail" and can be described by the Pareto distribution: F(x) =1-(a/x)b, where b<1. For this distribution law the cumulative sum of losses increases with time in a non-linear manner as ta, where a=1/b>1. Thus, the process is stationary, and the tendency of the non-linear loss growth is caused by an increase in probability of realisation of a huge disaster with time. The regime of non-linear increase of cumulative loss value should however saturate at some time Tc because of evident limitation of maximum possible loss value. Methods of robust evaluation of the saturation parameters (Tc and corresponding loss value Lc) and of the characteristics of distribution of rare strongest events with loss value L>Lc are presented. The obtained parameters values are examined in connection with the social and economic situation in different regions. It was shown that after the proper normalisation by density of population and by annual per capita income the losses have a tendency to decrease with the social and economic development. Thus the regime of losses from earthquakes appears to be compatible with conception of the sustainable development of society, moreover, it can be considered as an example of practical realisation of this conception. But the Pareto distribution law is typical also for damage values from other natural (floods, hurricanes) and man-made disasters. It means that the presented approach can be applied to these types of disasters as well. These cases are however essentially more complex because of connection of regime of disasters with the climate change and because of shortage of loss values data.

Citation: M. V. Rodkin and V. F. Pisarenko (2007), Data on losses from natural disasters. Tendencies of change in the recent world, in: Materials of the International Conference '50th Anniversary of the International Geophysical Year and Electronic Geophysical Year', GC RAS, Moscow, doi:10.2205/2007-IGY50conf.

© 2007 Geophysical Center RAS and authors


Webmaster