1. A system for generating a probability density to estimate the probability that an event will occur in a region of interest, comprising: a processor; programming executable on said processor for: inputting spatial event data comprising one or more events occurring in the region of interest; inputting auxiliary data related to the region of interest; wherein the auxiliary data comprising non-event data having spatial resolution; and calculating a probability density estimate for the region of interest based on a function of the auxiliary data and the event data.