Scientific management of subsistence materials during the COVID-19 outbreak in Changchun

In this paper, we firstly constructed an improved SEIR model to predict the development of the epidemic in Changchun without control measures and compared it with the actual situation; meanwhile, we introduced regenerative numbers to calculate 0R using realistic data and observed the interval of 0R before and after the distribution of vegetable packs. Secondly, the problem of planning multi-level logistics network planning for supply-demand balance is addressed for the design of preplanning for the orderly distribution of residents' living materials in the case of large-scale closure control. Meanwhile, according to the measurement standard of 400 grams of vegetables consumed per person per day, the material demand of each cell in the downstream of all networks is obtained. The real street route distance between each node is used as the weight of the edge in the ordered network graph, and then the transshipment volume of each midstream of the network is introduced, and similarly the transshipment volume of the midstream can be derived from the supply volume of supplies that need to be guaranteed to be provided in the upstream of the network. After that, large trucks (10T load) and small trucks (4T load) are used to transport materials respectively for comparison and analysis. In actual material distribution, trucks with corresponding load should be selected reasonably according to the scale of demand.