Shaping cities: A proposal for an integrative FEW nexus model

Advances to better understand the food, energy and water (FEW) nexus are still needed since most available approaches are non-integrated, complex, and focused on large scale, which makes them difficult in supporting public policies on small scales. This work proposes the FEW nexus cube model, a quantitative and integrated model to evaluate the FEW nexus of municipalities. FEW flows are independently quantified to show their demand by each municipality, they are then graphically represented in a 3-D cube to allow a criteriously-based integrated performance final rank that supports the identification of strengths and weaknesses for the municipality. The cube model is applied in nine Brazilian municipalities as case studies to show its potential for comparative assessments. Santos municipality is in the top ranking according to the criteria behind the cube model, being located in the so-called security cube region, without limiting FEW factor, and 0.80 for the FEW vector length. In 2018, Santos demanded 9.73E+ 07 m3H2Oeq., 2.08E+ 10 MJfossil-eq., and 6.87E+ 08 kgCO2eq., of which food & energy were the FEW flows that most influenced CO2 emissions and fossil energy demand, while food & water FEW flows have influence on the embodied water demand. Although outside the scope of this study, general policy recommendations are suggested for effective developing plans. This work contributes to the advancement of FEW nexus studies by providing an integrated, non-complex, and small-scale based model to achieve more resilient municipalities as emphasized by the United Nations in several of its 17 goals.

Automated summary

Further advances in understanding the food, energy and water (FEW) nexus are needed, particularly in supporting small-scale public policies. This study proposes the FEW nexus cube model, which quantitatively and integratively evaluates the FEW nexus of municipalities. The model identifies strengths and weaknesses of each municipality based on independently quantified FEW flows represented in a 3-D cube. Application of the cube model in nine Brazilian municipalities demonstrates its potential for comparative assessments.