Debris flow disasters are usually accompanied by serious loss of lives and properties. However, debris flows are also part of earth’s natural phenomenon, and so what is the reasonable budget to be spent on mitigation measures becomes an important issue for the budget allocation processes....

In quantitative risk analyses for natural hazards, vulnerability can be expressed as the ratio of reconstruction, replacement or reproduction expenses due to a damage caused by a certain process intensity and the original value of the element at risk exposed. To discuss the building...