Balancing stakeholder objectives in the water-energy-food nexus through dimension reduction and multi-actor decision strategies

Water, energy, and food are critical resources required to meet basic human needs, ensure economic development, and achieve sustainable development goals. However, the effects of rapid population growth and climate change have resulted in increased demand for these resources. Furthermore, water, energy, and food are highly interrelated, presenting both synergisms and trade-offs along their supply chains. The connection of these resources and the study of their interdependencies have been addressed in the literature as the Water Energy Food Nexus (WEFN). A critical aspect of WEFN systems is that they are integrated by multiple actors with competing goals and concerns. When addressing WEFN systems with optimisation tools, the incorporation of stakeholders’ interests increases the dimensions of the problem. In this study, we propose a dimensionality reduction approach based on a post-optimal analysis by imposing non-negativity constraints on specific actors’ economic goals. From the new problem with reduced dimensions, the TOPSIS multi-criteria decision analysis (MCDA) method was employed to select compromise solutions for the configuration of the WEFN system under different scenarios with varying importance for the analysed criteria. By coupling MCDA tools with dimensionality reduction strategies, this approach allows the analysis of fewer system configurations for reaching compromise without losing information when reducing the decision space. The study highlights the necessity for future research to adopt participatory approaches and consider societal opinions and concerns, thereby ensuring public acceptance in resource allocation and overall WEFN system management.