Designing climate-adaptable agricultural supply chain networks with heterogeneous regions for perishable food systems in Turkey: A sustainable multi-echelon optimization approach

This study develops a drought-aware agricultural supply chain network (AGSCN) for perishable crops at risk of drought, explicitly incorporating spatial zoning across heterogeneous farming regions with distinct production characteristics, including low- and high-risk zones. A bi-objective mixed-integer linear programming (BOMILP) model is formulated to simultaneously minimize total system cost and carbon emissions, thereby capturing economic efficiency and environmental sustainability considerations in perishable agricultural supply chain (AGSC) operations. The key contributions of this study are: (i) explicit integration of spatially heterogeneous production zones, enabling region-dependent production and allocation decisions under drought conditions; (ii) incorporation of region-specific drought disruption rates and yield factors to represent heterogeneous climate impacts on agricultural production capacity and supply chain performance; (iii) development of a unified BOMILP framework that jointly optimizes economic and environmental objectives in perishable AGSCNs; and (iv) a sequential multi-echelon distribution structure linking (iv) a sequential multi-echelon distribution structure linking farmers, local markets, wholesale markets, processing/export facilities, and consumers while accounting for capacity limitations and the operational characteristics of perishable agricultural products. A real-world case study of the Turkish tomato supply chain demonstrates the applicability of the proposed framework. The results show that increasing drought severity substantially changes regional sourcing patterns: the contribution of the high-risk Zone B to total supply decreases from approximately 45% under mild drought conditions to 22% under severe drought. In contrast, the model increases reliance on the more reliable Zone A, whose contribution reaches approximately 78% of the total network supply. These results demonstrate the model's ability to dynamically reallocate production and distribution flows in response to heterogeneous drought impacts while maintaining supply continuity. Overall, the findings highlight the importance of spatial diversification and adaptive sourcing strategies for improving the resilience and sustainability of perishable AGSCs under climate-induced disruptions.