Approaches and challenges of quantifying water-energy-food security nexus in urban areas

Abstract
Objective: The objective of the present study is to examine two widely adopted approaches for quantifying the water-energy-food security nexus in urban contexts: (1) input-output analysis grounded in modern resource management principles, and (2) the portfolio approach based on economic theory. Furthermore, the study aims to identify and elaborate on the key challenges associated with quantifying the nexus and developing a generalizable computational modeling framework—challenges that have remained largely unaddressed in previous research.
Method: A deeper understanding of these challenges facilitates the assessment of sectoral conflicts and supports the formulation of solutions that harmonize resource demand across different domains. The water-energy-food security nexus represents the integrated management of the most fundamental natural resources required to meet basic human needs, shaped by both internal and external drivers.
Results: Without adequate water resources, the production and distribution of various energy carriers becomes infeasible; likewise, without a reliable energy supply, access to available water resources cannot be ensured.
Conclusion: The absence of these two essential inputs places food security at significant risk. Although the interconnections among these three vital resources—water, energy, and food—are conceptually transparent, they are characterized by a highly complex and expansive network of interactions. 
 
 
 
English Extended Abstract
Introduction
Water, energy, and food are three foundational pillars of human survival and development, intricately linked in a dynamic and interdependent system. Without adequate water resources, the production and distribution of various energy carriers—such as hydropower, biofuels, and even cooling systems for thermal power plants—becomes severely constrained. Conversely, without a reliable energy supply, the extraction, treatment, and distribution of water resources are not feasible.
This mutual dependency means that any disruption in one component directly affects the others. Consequently, food security is placed at significant risk when either water or energy availability is compromised, as agricultural production relies heavily on both for irrigation, processing, transportation, and storage.
Although the interconnection among these three vital resources may appear straightforward at first glance, the underlying relationships are highly complex, multifaceted, and influenced by a wide range of internal and external factors—including climate change, population growth, urbanization, and economic development. The concept of the water-energy-food security nexus refers to an integrated management approach aimed at optimizing the use of these essential natural resources to meet human needs sustainably. It requires a holistic understanding of how decisions in one sector impact the others, and how to navigate trade-offs and synergies across the system.
The present study aims to explore and critically evaluate two prominent methodologies used to quantify the water-energy-food security nexus in urban environments: (1) input-output analysis, which is rooted in modern resource management and systems thinking, and (2) the portfolio approach, derived from economic theory, which emphasizes diversification and risk management in resource allocation.
In doing so, the study seeks to identify and articulate the key challenges that hinder the development of a robust and generalizable computational model for nexus analysis—challenges that have often been overlooked in previous research. These include data limitations, sectoral fragmentation, methodological inconsistencies, and the difficulty of capturing dynamic interactions over time.
By gaining a deeper understanding of these challenges, researchers and policymakers can better assess potential conflicts among sectors and devise strategies that promote balanced resource distribution, resilience, and long-term sustainability in urban settings.
 
Method
In general, the water-energy-food security nexus can be divided into the following groups from an economic perspective: (1) input-output analysis, (2) trade-off analysis, (3) economic modeling, (4) supply-chain analysis, (5) portfolio concept.
Given the frequency of input-output analysis in nexus studies, the concept and history of its integration to the water-energy-food security nexus in urban areas will be described. The concept of portfolio management will also be investigated as a new tool in quantifying the nexus concept.
 
Results
The nexus acts as a thread that interconnects a network of water, food, energy, climate, economic growth, and the challenges of human society that the global economy will face over the next two decades.
Therefore, establishing a systematic framework that can guide this interconnection toward achieving tangible economic outcomes that benefit society as a whole is essential. Although the term 'water-energy-food security nexus' may seem to refer solely to the management of fundamental resources, its intrinsic meaning encompasses the management of the challenges facing human society
 
Conclusion
Given the newness of the nexus concept, it is difficult to achieve integrated quantification methods that can be extended across all spatial and temporal scales and are compatible with the political and economic structures of different countries in the short term.
The present study investigated one of the most common methods of quantifying the nexus concept based on an economic theory and a new management method. The challenges in this field were also discussed, the resolution of which could be the subject of future research related to the concept of the water-energy-food security nexus.