引言地震危险性评估的关键是烈度衰减问题,许多学者曾提出过经验衰减公式,即参照震中烈度值I_0确定局部烈度值为I_2。该公式参数的确定使用简单的点源辐射(radiation)模型(Ambraseys,1985)和最小二乘法。考虑到资料的不确定性以及某些关系的不准确性,通常用一个分布(标准偏 INTRODUCTION The key point of earthquake risk assessment is the intensity decay problem. Many scholars have proposed the empirical decay formula, that is, the local intensity value is I 2 with reference to the epicenter intensity I_0. The formula parameters were determined using a simple point source radiation model (Ambraseys, 1985) and the least square method. Taking into account the uncertainty of the data and the inaccuracies of some of the relationships, a distribution is usually used (standard deviation