Net Virtual Cropland Flows and Network Structural Changes Among Chinese Cities: A City-Level MRIO and Complex Network Analysis

In China, cropland resources and agricultural production are spatially mismatched with population and consumption demand, making net virtual cropland flows important for interregional resource reallocation. Using city-level MRIO tables and cropland-use data for 2012, 2015, and 2017, we quantify net virtual cropland flows among 357 cities and construct a directed weighted network. Drawing on complex network theory, we assess its structural changes using structural metrics, the Weighted Rich-Club Coefficient, and Maximum-Capacity Betweenness Centrality. Virtual cropland flows are spatially uneven but relatively stable over time. Northeast and Northwest China are the main net exporters, whereas eastern coastal urban agglomerations and several major cities are the principal net importers, with significant spatial clustering. Between 2012 and 2017, average node strength and network efficiency increased, while weighted clustering declined and weighted assortativity shifted from near zero to negative values. Significant rich-club ordering persisted among core exporters and importers, but the strongest effect became concentrated within a smaller group of cities. Key intermediary roles spread from traditional national hubs to inland cities in Northeast China, North China, and the Central Plains. Overall, net virtual cropland flows across Chinese cities form a networked system structured around core cities, non-core cities, and key intermediaries.