Abstract
Introduction: In drought-prone regions characterized by natural resource scarcity, the simultaneous management of water, food, energy, and environment (WEFE) has evolved into a complex systemic challenge. Traditional, single-sector approaches often fail to achieve long-term sustainability, as they overlook the inherent interdependencies and the non-linear nature of nexus trade-offs. Consequently, a scientific understanding of WEFE nexus dynamics is essential for formulating optimal and resilient policies. This study aims to analyze long-term interactions and evaluate the impacts of various scenarios through an integrated approach, simulating the behavior of the WEFE nexus in Lordegan County. Given the escalating demographic pressures, this research examines the moderating role of population and resource management policies in enhancing systemic resilience.
Materials and Methods: A System Dynamics (SD) approach was employed to model the intricate interactions among key variables, including population, food, water, and energy demands, cropland area, forest cover, and greenhouse gas (GHG) emissions. Given the inherent complexity of the WEFE nexus, System Dynamics (SD) was adopted as a robust analytical framework. By leveraging fundamental mechanisms—namely feedback loops, stock-and-flow dynamics, and temporal delays—SD facilitates the modeling of intricate endogenous interactions. This enables the development of a high-fidelity representation of the system, making it an indispensable tool for understanding and managing the non-linear interdependencies characteristic of nexus frameworks. The simulation horizon spans from 2016 to 2041. The study designs three demographic scenarios based on Statistical Center of Iran projections, alongside dedicated water and energy management scenarios, and their integrated combinations.
Results and Discussion: Under the baseline scenario (1.15% growth rate), food, water, and energy demands are projected to reach 82,060 tons, 279.72 million m3, and 0.833 million barrels of crude oil, respectively, by 2041. Implementing population control policies (notably Scenario 2) significantly mitigates resource demand and GHG emissions by reducing cropland and forest cover. However, findings indicate that demographic management alone is insufficient for nexus sustainability. Compared to single-sector policies, the energy management scenario resulted in a 16.3% reduction in energy demand (to 0.678 million barrels), while the water management scenario achieved a 49% reduction in water demand (to 138.37 million m3). Ultimately, the integrated (combined) scenario emerged as the most efficient strategy for curbing demand and reducing the carbon footprint, recording the lowest energy demand (0.677 million barrels) and GHG emissions (1,952 kilotons), thereby underscoring the necessity of transitioning toward synergistic resource management.
Conclusion: The findings of this study conclusively confirm that achieving long-term sustainability within the complex water-food-energy triangle is strictly contingent upon the concurrent and synergistic implementation of robust energy demand management and significant water productivity enhancement. The simulation results demonstrate that demographic control measures, when applied in isolation, remain fundamentally inadequate to alleviate the escalating pressures on natural resources. Consequently, there is an urgent necessity to align national population policies with localized regional and agricultural development plans to ensure systemic stability. Therefore, it is strongly recommended to integrate water and energy policies through a comprehensive “Nexus Governance” framework, which should prioritize Integrated Water Resources Management alongside the adoption of smart, drought-resilient agricultural technologies. Ultimately, this study contributes a rigorous, quantitative System Dynamics-based framework, providing policymakers with a sophisticated operational tool to effectively navigate sectoral trade-offs and facilitate a structured transition toward holistic sustainable development.