Intensity based casualty models: case study of Bhuj and Latur earthquake in India

Casualty data from Latur (1993) and Bhuj (2001) earthquakes in India are analyzed to study the relationship of death rates with shaking intensity. A strong correlation is noted between intensity and death rates (correlation coefficient ~0.77). The expected (median) death rates are 0.31%, 1.77%, and 19.45% for intensity VII, VIII and IX in case of Latur, and 0.0029%, 0.049%, 1.92% and 4.92% for intensity VII, VIII, IX and X in case of Bhuj. The significantly higher death rates in Latur are due to building typologies and the time of the event. Thus, there

is a factor of ~100 for intensity VII and a factor of ~10 for intensity IX, indicating that the empirical casualty models should be area specific and not country specific. A two-parameter empirical model has been proposed.