Combined Optimization Of Post-earthquake Relief Delivery And Road Rehabilitation

Due to the high frequency of earthquakes happen in China, the whole country suffers great damage and losses every year. Once an earthquake happens, the amount of emergent relief demand is very large in the disaster areas, so it's extremely important to satisfy the demand timely and effectively in order to reduce the losses. It will be very hard to transport supplies to the disaster areas because the road to the disaster areas might be destroyed after earthquake. The condition of road repair is very important to save the people in the disaster area, which is one of the essential tasks needs to be done in the rescue activity. Researches about the emergent relief delivery and road rehabilitation are studied separately and the interaction of them is neglected. It is necessary to study the combined problem of relief delivery and road rehabilitation in order to optimize the whole emergency logistics system. In addition, the combined problem in the actual road network is more practical.Based on the summary of the existing researches and the analysis of the combined relief delivery and road rehabilitation, the integrated optimization problem is studies in the paper. This study was supported by National Natural Science Foundation of China (70771094), Sichuan Youth Science and Technology Foundation of China (09ZQ026-021), and China Postdoctoral Science Foundation (20090450637).Firstly, the combined problem of relief delivery and road rehabilitation in the initial phase of post-earthquake is studied in the paper. The road repair schedule is planned in the consideration of the probable route which could be selected when the relief is sent to the disaster areas, and the routing of the vehicle is selected on the basis of the road rehabilitation condition. So, based on the actual situation of post-earthquake relief activities, a bi-level programming model is formulated under the condition of incomplete information, timely and fairness of rescue. The relief demand is very large and vehicles are fully loaded during the whole rescue time. According to the characteristics of the model, the corresponding improved genetic algorithm is proposed. A numerical example is provided to validate the usage and effectiveness of the model and the algorithm.Secondly, the paper studies a dynamic, multi-objective model of the combined problem of relief delivery and road rehabilitation. The relevant information about the emergency rescue is more and more as the rescue goes on. New decisions should be made to adapt to the dynamic relief demand and road condition when information is updated. The relief demand is also very large and vehicles are fully loaded during the whole rescue time. Considering the actual situation of dynamic rescue, a dynamic multi-objective model is formulated and the corresponding algorithm is proposed to solve the model. A numerical example is provided to validate the effectiveness of the model and the algorithm in the paper.