Structure and toughness optimization of multi-layer weighted regional logistics network: taking the central region of China as an example

The operation of the regional logistics network is often interrupted by emergencies such as rainstorms and earthquakes, especially the COVID-19 pandemic in recent years. Therefore, it is particularly important to improve the toughness of the regional logistics network to resist the risk of emergencies. This paper firstly constructed a multi-layered weighted regional logistics network of highways and railways in the central region of China based on the gravity model, analyzed its network structure characteristics by using dominant flow and social network analysis methods, then simulated the evolution trend of network toughness under different strategies. Finally, the optimization model of logistics network structural toughness under fixed cost was proposed to explore the optimization path of network structural toughness. The results show that: (1) The economically developed cities are located in the core area of the regional logistics network, on the contrary, they are located in the edge area of the regional logistics network. (2) The network as a whole has formed a “two main and four auxiliary” distribution pattern with Zhengzhou and Wuhan as the two main cores in the north and south, and Taiyuan, Hefei, Changsha, and Nanchang as the four auxiliary cores. (3) The network has higher toughness under the node random order failure strategy than under the node specified order failure strategy, and the optimization plans improve the structural toughness of the regional logistics network by 11.68%.