Emergency logistics distribution model for disaster relief operations

Emergency logistics distribution is an important work in disaster relief operations.Considering the urgent relief needs right after disaster,a three-layer conceptual framework that including relief warehouses,relief distribution centers,and affected areas is developed.A bi-level optional model where flow allocation decisions are made at the top level,and the vehicle routing decisions are made at the base level is presented.According to the characteristics of the model,an improved ant colony algorithm is proposed to solve the base level model,and use CPLEX to solve the top level model.Numerical studies with a real large-scale earthquake disaster occurring in Wenchuan are conducted,and the corresponding results indicate the feasibility and efficacy of the proposed method.