Uncovering the structure and evolution of global virtual water and agricultural land network

Abstract

The effective management and allocation of water and land resources is pivotal for ensuring global food security and facilitating the transition towards sustainable development. Combining multi-regional input-output analysis and complex network modelling, this study examining the spatial-temporal evolution and topological structures of multi-layer virtual water and agricultural land networks, analyzed the network characteristics of different countries/regions, and tested the network vulnerability between virtual water trade network and virtual agricultural land network. From the results, it is revealed that 30.9 %—34.14 % of global water resources and 32.9 %—40 % of global agricultural land are associated with international trade. Meanwhile, the geographical distribution of this trade has shifted from low-income countries to middle and high-income countries, showing three distinct fluctuations in their instability levels. Additionally, quantitative network analysis indicates that resource trade networks exhibit small-world characteristics with increasing trends in network density, clustering coefficient, and average path length values over time. Among the two disturbance scenarios, both virtual water and virtual agricultural land networks were more vulnerable under deliberate assault than under random failure, however, the agricultural land network demonstrates greater toughness compared to the virtual water network. These findings highlight the importance of sustainably managing global water and land resources within a framework for sustainable development which aims at promoting both worldwide food security and environmental protection simultaneously.