A new method for expressing seismic hazards

The aim is to find a way to express seismic hazards with high accuracy, a wide range of exceedance probabilities and convenient application. We reviewed several commonly used methods for seismic hazards expression, and the "characteristic coefficient method" based on a new function to fit the seismic hazard curve is proposed, and the effect of this function was also verified by using the base data of the Seismic Parameter Zoning Map of China （GB 18306−2015）. The results show that the new function could effectively fit the seismic hazard curve, with a significant improvement compared to the extreme value function, and can adequatelyexpress the seismic hazards of a site. In addition, it is found that the parameter k （referred to as the characteristic coefficient in the paper）, which characterizes the shape of the curve in this function, is related to the seismic environment faced by the site, that is, the hazard contribution for sites with low values of k essentially came from the near field, while the contribution for sites with high values of k from long distances could not be ignored.