Bi-Objective Optimization On Location And Distribution Of Emergency Logistics With Road Repair

With the deterioration of the earth’s ecological environment and frequent sudden natural disasters all over the world,and the problem of post-disaster emergency logistics operation and management has gradually attracted widespread attention of the whole society.Earthquakes,floods,tsunamis and other extreme natural disasters can easily lead to the interruption of transportation infrastructure such as roads,bridges and tunnels,which further results in the disruption of emergency supplies distribution and other activities,posing huge challenges to post-disaster relief.Therefore,it is critical to repair the damaged road network timely and effectively for emergency relief.To meet the actual rescue needs of natural disasters such as earthquakes,this thesis studies the integrated optimization of road repair,emergency logistics location and distribution,in order to quickly output rescue planning in the post-disaster emergency response stage,help relevant emergency management departments to make scientific rescue decisions,and ensure the effectiveness and efficiency of disaster relief work.Firstly,this thesis describes the decision content and relationship between road repair,emergency logistics location and distribution.With the aim of minimizing the total deprivation cost and total relief cost,a bi-objective optimization model that integrates road repair,emergency logistics location and distribution is constructed.Secondly,a non-dominated sorting genetic algorithm II based on density peak clustering and floyd algorithm is developed to solve the problem.Specifically,the density peak clustering algorithm is used to quickly determine the location of disaster relief warehouses,the floyd algorithm is used to decide the road repair scheme,and the non-dominated sorting genetic algorithm II is used to solve the relief supplies distribution scheme.Then,several enhancement strategies,including the initial solution generation strategy,fixed point strategy based on clustering Silhouette Coefficient and variable neighborhood local search strategy,are proposed to improve the algorithm.Finally,numerical experiments of random generated instances and Wenchuan earthquake case are used to verify the effectiveness of the model and algorithm,as well as the scientificity of partial repair strategies in the post-disaster emergency response stage,and the relevant emergency management insights are refined.The results show that:(1)The model and algorithm in this thesis have good applicability,which can help decision makers make scientific disaster relief strategic planning under the trade-off between social cost and economic cost;(2)The three algorithm improvement strategies have obvious optimization effect,and the improved algorithm has better comprehensive solving performance,which can quickly generate better emergency logistics location distribution and road repair schemes;(3)The more serious the disaster is and the sparser the road network in the disaster area is,the more attention should be paid to the post-disaster road repair.In the emergency response stage,only the key damaged sections need to be repaired to efficiently support the rescue mission,thus saving manpower and material resources for the actual rescue and maximizing the rescue benefits.