Once the models probabilistically generate the characteristics of a simulated event, they propagate the event across the affected area. For each location within the affected area, local intensity is estimated. The intensity experienced at each site is a function of the magnitude of the event, distance from the source of the event, and a variety of local conditions.

Characterizing the intensity of natural hazards at individual locations requires the use of detailed databases at high resolution. Simulated wind events call upon digital land use/land cover data. The AIR European windstorm model, for example, incorporates a database of surface terrain and land cover characteristics at a resolution of 1km². Using this data, AIR modelers calculate a surface friction coefficient to obtain an estimate of surface roughness, which dictates, in part, how quickly wind speeds dissipate over land. The AIR earthquake models employ detailed soil and bore log data that reveal the material properties of the soils through which seismic waves pass. These determine the degree of soil amplification and potential for liquefaction at specific sites affected by the simulated event. To site just one example: the AIR soil database for the area around San Francisco Bay — an area with significant potential for liquefaction — has a horizontal resolution of 24m².

AIR researchers base their calculations of local intensity on empirical observation as well as on theoretical relationships between the variables. The local intensity components of all AIR natural hazard models undergo extensive validation using data from actual events.