  Evacuation shelters, which are urgently required during natural disasters,
are designed to minimize the burden of evacuation on human survivors. However,
the larger the scale of the disaster, the more costly it becomes to operate
shelters. When the number of evacuees decreases, the operation costs can be
reduced by moving the remaining evacuees to other shelters and closing shelters
as quickly as possible. On the other hand, relocation between shelters imposes
a huge emotional burden on evacuees. In this study, we formulate the
"Evacuation Shelter Scheduling Problem," which allocates evacuees to shelters
in such a way to minimize the movement costs of the evacuees and the operation
costs of the shelters. Since it is difficult to solve this quadratic
programming problem directly, we show its transformation into a 0-1 integer
programming problem. In addition, such a formulation struggles to calculate the
burden of relocating them from historical data because no payments are actually
made. To solve this issue, we propose a method that estimates movement costs
based on the numbers of evacuees and shelters during an actual disaster.
Simulation experiments with records from the Kobe earthquake (Great
Hanshin-Awaji Earthquake) showed that our proposed method reduced operation
costs by 33.7 million dollars: 32%.
