Examples range from contamination of the food or water supply, to high levels of air or noise pollution, a chemical accident, a disease outbreak or a natural disaster.
From his ringside seat on natural disaster, Mr Toda has no doubt that even the richest and most advanced societies cannot expect to defy geological realities.
It tells the story of men and women who, in the course of the major events of the last 150 years, have given assistance to victims of wars and natural disasters.
His proposal is to start by using solar systems with associated batteries to do much of the work that diesel generators do in post-calamity situations.
With its complexity, the deformation mechanism and stability study of Badong large slope system is very important to emigration project and geologic hazard control.