关键词: 应急救援, 等级置信度, 时间约束, 动态指派

Abstract: Earthquake disasters have occurred frequently all over the world in recent years. On August 14, 2021, a 7.2-magnitude earthquake struck Haiti, killing more than 2200 people; On September 28, 2018, a 7.5-magnitude earthquake and tsunami struck Indonesia, killing 2091 people, injuring 10679, and leaving 680 missing; On April 25, 2015, a 7.8-magnitudeearthquake struck Nepal, killing more than 8800 people; On March 11, 2011, a 9.0-magnitudeearthquake and tsunami struck off the northeast coast of Japan, killing nearly 20000 people; On January 12, 2010,a 7.0-magnitude earthquake struck Haiti killing as many as 316000 people; And on May 12, 2008, a 7.9-magnitude earthquake struck eastern Sichuan, China, killing more than 60000 people. Large-scale earthquake disasters have become the focus and difficulty of research due to their wide range of impacts, hugely affected populations, severe economic losses, high degree of uncertainty, as well as their derivative disasters and their evolution characteristics. Existing studies have mainly focused on the dispatching and distribution of emergency supplies, while ignoring the role of people. In the process of emergency rescue after a disaster, the rapid and effective deployment of rescue teams is the premise and foundation of the emergency rescue work, and it is also an important guarantee to reduce the casualties and property losses at the affected sites.
After a devastating earthquake, decision makers need to consider factors such as the number of rescue teams, the demand for rescue teams at each affected site, and the arrival time of rescue teams at the affected site, so as to make continuous multi-stage dynamic decisions on different dispatch tasks under different scenarios in multiple stages. In the multi-stage emergency decision-making problem, the decision of the previous stage will have an impact on the decision of the later stage, so the decision maker must consider the interactions between decisions made in adjacent stages in a thoughtful manner to ensure that the overall rescue work is carried out efficiently. On the other hand, in order to implement effective rescue operations, decision makers must also make a reasonable assessment of the efficiency of rescue teams relative to each disaster site. However, in the early post-earthquake period, the affected population, the extent of the damage, and the characteristics of the affected areas are often subject to significant uncertainties. Decision makers need to consider a number of factors when assessing the rescue efficiency, such as the number of rescue teams, their experience accumulation, the rescue equipment, the communication equipment, and their tactical level. For example, disaster sites with large populations but low earthquake intensity will have more requirements for the number of personnel in the rescue team than for the rescue equipment. On the contrary, disaster sites with less population but high earthquake intensity will have more requirements for the level of equipment and technology in the rescue team. Therefore, decision makers need to carefully analyze and assess the situation at different affected sites in order to rationalize the allocation of rescue resources and ensure the maximum effectiveness of rescue operations.
Evidential reasoning (ER) is suitable for uncertain problems with incomplete, imprecise and unknown assessments, and is widely used in risk assessment and emergency management. In view of this, for the continuous dispatch of emergency rescue teams after a disaster, the ER theory is introduced into the post-earthquake emergency rescue dispatch model, and the efficiency matrix of the rescue team for the affected sites is constructed by expanding the weight dimension of evidential reasoning according to the initial disaster information of the affected sites. Based on the rescue time constraints, the rescue sub-schemes of each stage are constructed. By taking into account the dynamic feasibility of the sub-schemes of the adjacent stages, a multi-stage dynamic time-limit optimization model is established to maximize the efficiency of the whole rescue process. The solution algorithm is given according to the model characteristics. Finally, the solution process and the optimal dispatching scheme are determined through examples, from which the following conclusions can be drawn: (1)Single-stage decision-making often fails to meet the emergency demand, so it is necessary to consider the rescue time constraints and the dynamic feasibility of the stage rescue; (2)The use of the level confidence can effectively determine the rescue efficiency of the rescue team relative to the various affected sites, and provide the prerequisites for the realization of effective rescue; (3)The feasibility and effectiveness of the model and algorithm are verified.The next step will be to study the continuous dynamic assignment of rescue priority in the case of insufficient rescue force.

Key words: emergency rescue, level confidence, time-limit, dynamic dispatch