Evaluating the performance of intensity prediction equations for the Italian area

Abstract

In this study, we evaluate the performance of five recent Intensity Prediction Equations (IPEs) valid for Italy comparing their predictions with intensities documented at Italian localities. We build four different testing datasets using the data contained in the most recent versions of the Italian Parametric Earthquake Catalogue CPTI15 and Macroseismic Database DBMI15 and we estimate the residuals between observed and predicted intensity values for all the selected IPEs. The results are then analyzed using a measure-oriented approach to score each model according to the goodness of model prediction and a diagnostic-oriented approach to investigate the trend of the residuals as a function of the different variables. The results indicate the capability of all the tested IPEs to reproduce the average decay of macroseismic intensity in Italy although with a general underestimation of high-intensity values. In addition, an in-depth investigation of the spatial and temporal patterns of the event residual term, computed using the best predictive model, is carried out. Lastly, we provide some hints for the selection of calibration datasets for the development of future intensity attenuation models.