Research On The Layout Planning Of Vaccination Sites Under Major Public Health Emergencies

Major regional and global public health emergencies occur from time to time,,especially the outbreak of COVID-19 at the end of 2019,which not only poses a serious threat to the lives and safety of the people.It has also brought a huge negative impact on the economic development and stability of our country and even the whole world.After the occurrence of public health emergencies,in order to restore society to normal as soon as possible and reduce casualties as much as possible,vaccine research and development and universal vaccination have become the most effective way.After the successful development of the vaccine,the completion of universal vaccination is the key to the realization of mass immunity.Among them,the layout planning of vaccination sites is very important to improve the efficiency of vaccination,complete universal vaccination as soon as possible,and let the vaccine play its role in controlling the epidemic.Therefore,the research on the layout planning of vaccination sites under major public health emergencies is of great significance to reduce the harm of the epidemic and maintain public safety.In order to solve the problem of location of public service facilities,scholars often use accessibility analysis and interactive improvement.A more formal method is to construct linear programming models such as location set coverage model(LSCP),maximum coverage model(MCLP),P-median model(PMP)and Pmedian model with capacity constraints(CPMP)for location selection,and good planning results are obtained.However,according to the layout planning of COVID-19 vaccination site in Kaifeng City,the existing model has some limitations,such as it is difficult to realize the integrated location of urban and rural areas,and the planning time of emergency state location is too long.In order to solve these problems,according to the characteristics of vaccination,the vaccination is divided into two scenarios: emergency and non-emergency,and mathematical models are established to plan the vaccination points of the two scenarios.In the non-emergency scenario,this paper uses the classical location model and the improved model for facility location.The case study shows that:(1)The LSCP model has the strongest fairness in the planning results,and the facilities are evenly distributed in space,which can maximize the utilization of resources,but the number of urban facilities is small and does not match the population density;After using the variable radius improved LSCP model,the number of urban facilities increases and the overall planning quality is improved.(2)There is also a mismatch between the layout of facilities and the distribution of population in the planning results of MLCP model.After using the improved MLCP model with variable radius,the rationality of facility layout is improved.(3)The PMP model aims at the total travel distance,but does not take into account the travel distance of some demand points,which may lead to poor fairness in planning;The improved PMP model with variable radius can reduce the maximum travel distance,reduce the unfairness of some location public services,and better realize the overall layout of urban and rural facilities.To sum up,according to the different service radius of urban,county and rural areas,the classical location model is improved,the facility layout planning is more reasonable,and the urban-rural integration planning of public service facilities can be better realized.Considering the service capacity limitation of service facilities,this paper further uses the capacityconstrained PMP model(CPMP)for facility layout planning,and introduces variable radius constraints to improve the model.The case study shows that in the case of uneven population density,the planning result of the CPMP model with variable radius constraint is better than that of the PMP model,which can achieve the balance between supply and demand of facilities and services,and avoid the excessive population of a few facilities,but there are still some locations that travel too far.After using the variable radius improved CPMP model,it can not only consider the service capacity of facilities,but also effectively reduce the travel distance of a few locations,which is more suitable for the urban-rural integration planning of public service facilities.In emergency scenarios,the strategy of vaccination in China is usually: urgently mobilize social medical forces,set up a number of working groups,through "slicing and dry" way of rapid vaccination.The classical location model is difficult to adapt to the selection of corresponding facilities.In this paper,the equal zoning model is used for regional zoning and facility location.The case study shows that the equal partition model can quickly complete the emergency planning,the shape of the planning area is compact and continuous,the task is equal,and it is convenient for the rational allocation of resources.In practical application,it can avoid the long-distance flow of vaccination personnel and reduce the risk of infection;the number of service personnel is balanced,and the overload of medical staff can be avoided,which is conducive to the rapid completion of the overall vaccination task.The main contribution of this paper has two aspects:(1)Using the variable radius constraint to improve the classical location model to make it better meet the urban and rural integrated public service layout facilities;(2)Aiming at the emergency vaccination scene,the "slicing and dry" work mode is adopted,and the equal zoning model is introduced to better meet the needs of emergency services.