Developing a National-Scale Hybrid System Dynamics, Agent-Based, Model to Evaluate the Effects of Dietary Changes on the Water, Food, and Energy Nexus

“The pressing issue of the impact of changing agricultural policies on the water, food, and energy nexus is of utmost importance in today’s world. This issue is particularly critical in countries currently grappling with a severe water crisis. This work develops a national-level water, food, and energy (WFE) nexus model using a combination of system dynamics modeling (SDM) and agent-based modeling (ABM). The WFE model focuses on water resources, with agriculture being the primary user. A model agent was designed for agriculture which includes a variety of agricultural products with varying yields, blue water and greywater consumption, energy consumption, and land area under cultivation for each crop. This paper’s systems dynamics model is intended for application to meet the nutritional needs of a country’s population by balancing water and energy resources and consumption while maintaining food security. The model’s application covers two scenarios in Iran, a country under severe water stress. The first scenario involves nutrient supply based on the current diet, while the second scenario suggests a lacto-ovo diet. The outcomes of this study reveal that both scenarios can would lead to water and energy savings. For example, the implementation of Scenario 1 and 2 can reduce the groundwater storage deficit that occurred during the five-year study period by approximately 65% and 85%, respectively. Furthermore, based on the high volume of water saved in both scenarios, the increase in the volume of greywater is deemed neither significant nor hazardous. Considering new policies of agricultural production can lead to a new balanced diet in terms of nutrients and energy, which can impact the achievement of sustainable WFE resources. The findings of this research could prove beneficial for national policymakers who seek to promote sustainable WFE resource management.”

(Citation: Kheirinejad, S., Bozorg-Haddad, O., Savic, D.A., et.al. – Developing a National-Scale Hybrid System Dynamics, Agent-Based, Model to Evaluate the Effects of Dietary Changes on the Water, Food, and Energy Nexus – Water Resour Management (2024) – DOI: 10.1007/s11269-024-03829-5)