RESUMEN
This paper evaluates the mitigation effect of Tokai earthquake measures on housing damage using a counterfactual approach. It focuses on those measures that stimulate ex-ante investment in disaster prevention in the supposedly affected area, including earthquake-proof retrofitting and improved housing construction; the effect of the measures on housing losses is estimated monetarily. The study compares factual disaster damage computed using a real distribution of houses with counterfactual damage to a hypothetical housing distribution that would occur if the measures were not implemented. The key findings are: (i) the disaster mitigation effects of Tokai earthquake measures on housing amount to approximately JPY 18 billion (USD 0.18 billion) for Yamanashi Prefecture and JPY 0.26 trillion (USD 2.6 billion) for Shizuoka Prefecture, which would be at the centre of the event; (ii) a before-after comparison biases estimates of the mitigation effect; and (iii) statistically, the measures do not mitigate the housing damage predicted for an earthquake in Tokai.
Asunto(s)
Desastres , Terremotos , Vivienda , Humanos , Japón , Medición de Riesgo/métodosRESUMEN
Propagation and scattering of antiplane shear waves within media with two-dimensional cavities are numerically simulated, and the attenuation and phase velocities are experimentally determined. The results are compared with the predictions by the Foldy theory and its three corrected versions. If the cavity concentrations are small such as 0.02, the differences among the theoretical predictions are insignificant, and every theory is consistent with the experimental results. For higher concentrations such as 0.1, the differences become significant, but there are no objective grounds to say that any of the corrected versions of the Foldy theory works better than the original. If the error tolerance is as high as 10%, the simple Foldy formula may remain useful for concentrations up to about 0.1.
