Locating disaster response facilities in Istanbul

We study the problem of locating disaster response and relief facilities in the city of Istanbul, where a massively destructive earthquake is expected to occur in the near future. The Metropolitan Municipality of Istanbul decided to establish facilities to preposition relief aid and execute post-disaster response operations. We propose a two-tier distribution system that utilizes existing public facilities locally in addition to the new facilities that will act as regional supply points. We develop mathematical models to decide on the locations of the new facilities with the objectives of minimizing the average-weighted distance between casualty locations and closest facilities, and opening a small number of facilities, subject to distance limits and backup requirements under regional vulnerability considerations. We analyze the trade-offs between these two objectives under various disaster scenarios and investigate the solutions for several modelling extensions. The results demonstrate that a small number of facilities will be sufficient and their locations are robust to various parameter and modelling changes.