Shahid Beheshti University Advanced Environmental Sciences 3115-7173 22 1 2024 03 20 Investigating of Water, Energy, and Food Nexus with the Systems Dynamics Approach; a Case Study of Varamin Plain Investigating of Water, Energy, and Food Nexus with the Systems Dynamics Approach; a Case Study of Varamin Plain 1 20 103781 10.48308/envs.2023.1229 FA Alireza Shahmohammadi Department of Agroecology, Shahid Beheshti University, Environmental Sciences Research institute, Shahid Beheshti University, Evin, Tehran, Iran Korous Khoshbakht Department of Agroecology, Shahid Beheshti University, Environmental Sciences Research institute, Shahid Beheshti University, Evin, Tehran, Iran Hadi Veisi Department of Agroecology, Shahid Beheshti University, Environmental Sciences Research institute, Shahid Beheshti University, Evin, Tehran, Iran Mohammad Reza Nazari Environment and Natural Resources Economics Department, Environmental Sciences Research Institute, Shahid Beheshti University, Tehran, Iran Journal Article 2023 03 10 Introduction: Climate and ecosystem changes in coordination with other factors have challenged many basic paradigms of natural resource management. The purpose of this research was to know the correlation between water, energy, and food in Varamin Plain by the method of the mental model and the dynamics of water, energy, and food correlation under political scenarios. Material and Methods: Data and relationships related to the mental model were collected through interviews with the farmers and managers of the region using the Mental Modeler software. Data related to the correlation dynamics model was also collected through organizations, regional stakeholders and authoritative articles. The WEF nexus model developed for the study area consists of interconnected relationships for modeling water, agriculture and energy subsystems and their interactions. The simulation model was built using Vensim software, and the simulation period was considered a 20-year period. The equations in each subsystem were created based on the basic equations of the system dynamics approach and the causal loop diagrams of each subsystem using relationships and positive and negative feedbacks. Results and Discussion: The results of system dynamic modeling showed that the state of surface water resources and water security of the plain will be 158 million cubic meters and -162 million cubic meters, respectively, during the period of 20 years, which shows the reduction of resources compared to the original situation. The results of the model without applying the scenario showed that the volume of the Varamin Plain aquifer will decrease from 4000 million cubic meters to 2700 million cubic meters during the 20-year period. This shows that the policies of providing water resources, including the excessive use of wells, the development of urbanization and the creation of industries, as well as the lack of increase in the productivity of agricultural water through modern irrigation methods, are the reasons for such a problem. The application of scenarios for the allocation of the environmental needs of the Bandalikhan wetland showed that the plain will not have the ecological capacity to allocate water to the wetland, so that in the next 20 years, the water security of the plain will decrease to 180 million cubic meters. Also, applying the scenario of increasing irrigation efficiency without increasing the cultivated area from 58% to 70% was effective in improving the reduction of agricultural water demand and increasing the cultivated area. The increase in cultivated area up to 41,600 hectares had a positive effect on agricultural water demand, but more than this amount caused the pressure on water resources to increase. Based on the limitations of water resources and the reduction of water security in the Varamin Plain, the production of the plain's products will also face a decrease. Due to its proximity to the city of Tehran, the Varamin Plain plays an important role in meeting the needs of the people of Tehran and the surrounding cities. Conclusion: Examining the results and comparing the data showed that during the 20-year period, Varamin Plain will have an unfavorable situation regarding water resources and food production. The management of the resources of Varamin Plain requires a change in organizational, agricultural and developmental approaches. The development of solar systems in order to meet the energy needs, the establishment of the wastewater treatment plant in Varamin and the development of the treatment plant south of Tehran, as well as moving towards sustainable compression is effective in creating the stability of the plains resources in order to properly exploit the resources. On the other hand, increasing the irrigation efficiency without increasing the cultivation area can help in balancing the current situation so that with the implementation of the policies of the sixth development plan, the demand for agricultural water will be reduced to some extent and the pressure on the underground water resources will be reduced. Introduction: Climate and ecosystem changes in coordination with other factors have challenged many basic paradigms of natural resource management. The purpose of this research was to know the correlation between water, energy, and food in Varamin Plain by the method of the mental model and the dynamics of water, energy, and food correlation under political scenarios. Material and Methods: Data and relationships related to the mental model were collected through interviews with the farmers and managers of the region using the Mental Modeler software. Data related to the correlation dynamics model was also collected through organizations, regional stakeholders and authoritative articles. The WEF nexus model developed for the study area consists of interconnected relationships for modeling water, agriculture and energy subsystems and their interactions. The simulation model was built using Vensim software, and the simulation period was considered a 20-year period. The equations in each subsystem were created based on the basic equations of the system dynamics approach and the causal loop diagrams of each subsystem using relationships and positive and negative feedbacks. Results and Discussion: The results of system dynamic modeling showed that the state of surface water resources and water security of the plain will be 158 million cubic meters and -162 million cubic meters, respectively, during the period of 20 years, which shows the reduction of resources compared to the original situation. The results of the model without applying the scenario showed that the volume of the Varamin Plain aquifer will decrease from 4000 million cubic meters to 2700 million cubic meters during the 20-year period. This shows that the policies of providing water resources, including the excessive use of wells, the development of urbanization and the creation of industries, as well as the lack of increase in the productivity of agricultural water through modern irrigation methods, are the reasons for such a problem. The application of scenarios for the allocation of the environmental needs of the Bandalikhan wetland showed that the plain will not have the ecological capacity to allocate water to the wetland, so that in the next 20 years, the water security of the plain will decrease to 180 million cubic meters. Also, applying the scenario of increasing irrigation efficiency without increasing the cultivated area from 58% to 70% was effective in improving the reduction of agricultural water demand and increasing the cultivated area. The increase in cultivated area up to 41,600 hectares had a positive effect on agricultural water demand, but more than this amount caused the pressure on water resources to increase. Based on the limitations of water resources and the reduction of water security in the Varamin Plain, the production of the plain's products will also face a decrease. Due to its proximity to the city of Tehran, the Varamin Plain plays an important role in meeting the needs of the people of Tehran and the surrounding cities. Conclusion: Examining the results and comparing the data showed that during the 20-year period, Varamin Plain will have an unfavorable situation regarding water resources and food production. The management of the resources of Varamin Plain requires a change in organizational, agricultural and developmental approaches. The development of solar systems in order to meet the energy needs, the establishment of the wastewater treatment plant in Varamin and the development of the treatment plant south of Tehran, as well as moving towards sustainable compression is effective in creating the stability of the plains resources in order to properly exploit the resources. On the other hand, increasing the irrigation efficiency without increasing the cultivation area can help in balancing the current situation so that with the implementation of the policies of the sixth development plan, the demand for agricultural water will be reduced to some extent and the pressure on the underground water resources will be reduced.

https://envs.sbu.ac.ir/article_103781_2080488f112082ca1fb350495fffd83b.pdf