  Evacuation planning is an important and challenging element in emergency
management due to the high level of uncertainty and numerous players and
agencies involved in the event. To address all the factors with conflicting
objectives, mathematical modeling has gained an extensive application over all
aspects of evacuation planning to help responders and policy makers evaluate
required time for evacuation and estimate numbers and distribution of
casualties under different disaster scenarios. Correspondingly, mathematical
formulation of evacuation optimization problems and solution methods are
important when planning for evacuation. In this paper, the bi-level programming
formulation of shelter location-allocation problem is considered. To account
for stochasticity, a scenario-based approach is taken to address the
uncertainty in the population to be evacuated from a small town in Lombardy
region, Italy. Genetic algorithm is used as the solution method. Four scenarios
are considered to study the optimal number and location of shelters for
evacuation during normal weekdays, at nights, during weekends, and during
vacation times with visiting travelers. The results highlight how different
scenarios need different number and location of shelters for an optimal
evacuation.
