Adapting irrigated agriculture to climate change in arid regions: A hydroeconomic optimization approach.

Climate change presents considerable challenges to agricultural production. The integration of autonomous and planned adaptation is a critical concern for developing effective climate adaptation strategies in arid irrigated agriculture, which is subject to multifaceted stresses of water scarcity, salinization and climate change. To identify effective climate adaptation strategies, we developed an integrated hydroeconomic optimization model that incorporates agro-hydrological processes and climate change impacts into an economic optimization framework for climate-adaptive allocations of agricultural water and land resources. The model was calibrated using the Positive Mathematical Programming (PMP) method, which enables replicating base-year observations, and was applied to the Hetao Irrigation District (HID) in Inner Mongolia, China. Three planned climate adaptation strategies were designed to drive the model to quantify the effectiveness of integrated autonomous and planned adaptations in effectively alleviating compound climate and salinization stresses. The results indicated that crop yield enhancement through the adoption of stress-resilient crop varieties and necessary investment in drainage capacity are promising for effectively mitigating adverse impacts imposed by climate change and salinization in the HID. The adaptation analysis informed by hydroeconomic optimization provides useful insights for designing adaptation strategies to cope with compound stresses from water scarcity, salinization and climate change, while enhancing climate resilience and balancing economic and environmental sustainability for irrigated farming in arid and semi-arid regions.