Understanding the circulation network of agro-products in China based on the freight big data

The circulation process of agro-products plays a pivotal role in ensuring food security. However, factors that drive the agro-products circulation are still lacking of investigation. Here, we build three circulation networks of grains, vegetables, and fruits between cities in China based on 7,913,054 online freight orders and explore how the sectors of production, transportation, sales, and consumption affect the formation of circulation networks. By integrating four centrality measures into one comprehensive indicator, we quantify the importance of cities in circulation networks and reveal the hierarchical pattern of cities, which can be explained by the city attributes, such as economic level, natural resources, and so on. Based on the exponential random graph model, it is further found that the interaction effects among heterogeneous cities, including the agricultural productivity gaps, transportation disparities, relative wholesale competitiveness, and information technology gaps, facilitate the formation of links in the circulation network of agro-products. Our study not only deepens the understanding of the agro-product circulation networks at the city level, but also provides the guidance of guaranteeing food security and sustainability from the perspective of big data.