The map is a simplified world grain market: four exporting nations (Ukraine, Russia, USA, India) ship wheat, corn and rice along fixed trade routes to four import-dependent nations (Egypt, Nigeria, Bangladesh, Yemen). Route thickness and the glowing particles flowing along each arc represent real cargo tonnage. Pick an exporter and a shock type, then raise intensity: drought cuts that country's harvest at the source, conflict blocks its ports and rail lines outright, and export ban models a government restricting sales abroad to protect its own domestic price — all three ultimately shrink the same variable, exportable supply, but a ban can be reversed instantly while a lost harvest cannot.
price index = 100 · Σ(baseline flow) / Σ(actual flow)
actual flow_ij = weight_ij · exportFactor_i
food security_j -= shortfall_j · decay · dt (recovers when flow is restored)
- Exporter affected — which producing nation the shock hits; each ships a different mix of routes, so the same shock hits different importers hardest.
- Shock intensity — how severe the drought/conflict/ban is, from unaffected to a near-total halt of that country's exports.
- Simulation speed — how fast trade flow, price and food-security reserves respond and recover.
Real-world relevance: this mirrors 2022, when Russia's invasion blocked Ukrainian Black Sea grain exports and several countries (including India, on rice) imposed export restrictions of their own to shield domestic supply — both moves pushed global grain prices sharply higher and hit import-dependent nations like Egypt and Yemen hardest, since they had the least ability to substitute the lost tonnage.