Mapping global cereal flows at subnational scales uncovers heterogeneities in sourcing dependencies

Journal article

Subnational data on both domestic and international cereal flows is essential for understanding food supply chain vulnerabilities, yet no such dataset exists at a global scale. This study estimates spatially resolved cereal flow networks across 3540 subnational regions in 195 countries using a triply-constrained spatial interaction model that simultaneously enforces regional supply-demand balance and consistency with reported bilateral trade statistics. Domestic distribution accounts for approximately 25% of global cereal consumption, and 17% is met through international trade. Nearly half of net importing countries contain surplus regions that supply grain domestically, while virtually every net exporting country retains deficit regions reliant on inflows. Crop-disaggregated supply profiles reveal that subnational regions with similar aggregate trade dependency can have fundamentally different supply structures, differing in which crops dominate their consumption, whether those crops are sourced locally, domestically, or internationally, and how concentrated their sources are. Source concentration over exporting countries varies across subnational regions and across crops, revealing vulnerability hotspots that national-level assessments cannot detect. These subnational, crop-specific flow estimates can support targeted policy interventions to reduce supply chain vulnerabilities and enable more spatially precise environmental footprinting of food supply chains.

Authors: Jain, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Environmental Research: Food Systems
• Volume: 3
• Issue: 2
• Pages: 021002
• Article number: 021002
• Publication date: 2026-06-02
• Acceptance date: 2026-05-07
• DOI: 10.1088/2976-601x/ae69e9
• EISSN: 2976-601X
• ISSN: 2976-601X
• Language: English
• Keywords: global food flows; subnational; food systems resilience