Article Type: ReviewFood and water security are one of the most critical subjects in all countries. Water deficiency is turning to a national crisis in Iran, due to climate change and non-optimal management of water resources. Due to the increase in water tensions, the national production will encounter major challenges which will lead to more dependency on importing foodstuff. It is notable that in the future, water deficiency will not be due to water shortage, but could be the consequence of the weakness in the regulations, inappropriate policies, and unplanned use of water resources. Accordingly, water governance in Iran has become a crucial concern in the context of increasing water deficiency, local and border water conflict, and global climate changes. Drying of water basins and the decline of groundwater is the result of the aforementioned regulations. Altogether, in the current situation of Iran, in order to guarantee the production of sustainable food products, considering the worsening state of water shortage, it is necessary to notice good governance, along with the empowerment of indigenous communities and the revival of their knowledge in areas related to the conservation and optimal utilisation of water resources. In this study, while addressing different dimensions of water governance and its role in water and food security, the innovative water governance methods have been described in the field of water security compared to conventional methods of integrated water resources management.

The inadequacy of water resources to meet the needs of food production is a very important issue that will increase in importance in the future. If local renewable water sources (in soil) and water (in rivers, lakes, reservoirs, aquifers) are sufficient to produce a reference food supply (including 3000 kcal of daily requirement, of which animal products include 20 percent) for all residents. If not, we consider a food production unit to have a lack of green-blue water. If it is not enough for all residents, we consider a food production unit to have a lack of green-blue water. The number of people living in food production units affected by green-blue water scarcity has increased from 360 million people in 1905 (21% of the world's population at that time) to 2.2 billion (34%) in 2005. During this period, the lack of green-blue water has spread to large areas and has increased in previous areas. Water security is a concept that is examined in different dimensions and aspects. Four dimensions of these cases were identified, each of which consists of two complementary aspects: direct-indirect, macro-micro, technical-political and peace-conflict. In this study, the indirect role of water on food security on a global scale was investigated using a quantitative spatial approach. Since food security is intertwined with water security in many ways, the role of water scarcity on the disruption of food production and the impact of trade on this interaction was analyzed, and while examining the relationship of social resilience with these issues, the areas that It was identified that they were facing certain challenges in this field. With this work, the concept of water security became systematic and finally related to the issues of vulnerability, resilience and sustainability.

Today, scientific research on the types of Nexus, especially the water- energy- food Nexus as the driver of improving the welfare of society, is expanding. Since the Nexus approach is relatively new and requires the cooperation of several fields, explaining the concepts, its literature review, with a special focus on the water- energy- food Nexus is essential. This article aims to express Nexus approach simple and clear, by a detailed review of several related articles from 2011 to 2021. Articles were reviewed and categorized by year, source variety, and topic. So the outline of the formation of the Nexus approach, water- energy- food Nexus and the questions raised about this approach were codified in a way that provides a practical insight for policy making. In general, the Nexus approach, especially the water- energy- food Nexus which creates a very complex system and must be considered from a political, social and economic perspective, is difficult to implement. However, the Nexus approach is transitioning to an important component of development planning, and its success requires the guidance of strategic policies and institutional structures in multilevel governance. It seems that countries need to reform their governance structures in line with the Nexus approach. Another issue that has been considered in this article is the difference between the Water- Energy- Food Nexus approach with the approach of integrated water resources management. Due to the similarities, there are doubts about the need to move from integrated water resources management to Water- Energy- Food Nexus.

Introduction: Due to climate change that is happening, the security of water and food in Iran has caused many worries, which include small towns like Boroujerd. A comprehensive assessment is necessary as well as the productivity of water resources, because it can provide information for government agencies and the public to develop appropriate patterns. The aim of this study is the use and productivity of water resources in Borujerd city, the aim of this study to utilize appropriately the existing water resources in the city of Boroujerd and it is based on recycling and reusing water resources and reduced harvesting of ground water. So the potential of water saving and return to the cycle has been evaluated, and the results can be used as a potential solution for water shortage in Boroujerd in the future.Materials and Methods: Water, energy, and food security globally are achieved through a communication approach, an approach that integrates governance and management into all over sectors and scales. A communication approach can support the transition to a green economy which aims instead, among other things, the use of resources and policy coherence. Given the increasing communication between sectors in space and time, reducing economic, social and adverse environmental concerns can increase overall resource efficiency, more benefits and provide human rights for water and food. Therefore in a relationship-based approach, common policy and decision making an approach which reduces the composition and creates collaboration among sectors is in need.Currently, the most reliable tool to produce climate scenarios is the paired 3D Atmosphere-Oceans General Circulation Models which called AOGCM in this paper. AOGCM is based on the physical relationships that are presented by mathematical relations. In formulating its AR5 synthesis report, the IPCC has made use of new RCP scenarios of greenhouse gas (GHG) emissions. The IPCC society has used new scenarios as trajectory representatives of various concentrations of greenhouse gases. New scenarios have four key trajectories called RCP2.6, RCP4.5, RCP6.0 and RCP8.5 that are based on their radiative stimulus in 2100 and different specifications of the technology level, social and economic situation and future policies.LARS-WG is a random weather generator that can be used to simulate atmospheric data at a station under current and future climate conditions. The first version developed in Budapest in 1990 as part of an agricultural risk assessment in Hungary, then reviewed and moderated by Semenov in 1998. This model produces a daily time series of minimum and maximum temperature, rainfall and solar radiation.Results and Discussion: Concerning precipitation variations, it can be concluded that changes in winter months from January to March in RCP2.6 will decrease by 20%. Rainfall variations in the spring are the same and have equal status with the base time. In summer, two scenarios experience a 40% reduction, in fall, RCP2.6 shows a 20% increase in rainfall and the scenario RCP8.5 shows about 10% precipitation reduction. The two scenarios show at least 1.5 degrees Celsius increase and the highest increases are in fall, and in October, a rise of 2.5 degrees has seen. Maximum temperature changes which indicate the temperature increase to 2 degrees at least in both scenarios. In scenario RCP8.5, in winter and fall, the maximum temperature is increased to 2.5 and 3 degrees, respectively. Boroujerdʼs water and sewage company harvests 22 hm3 (MCM) water annually for its population of 240,654 people. If the necessary measures are taken for gray and black water purification, Boroujerdʼs daily city sewage that is 35416/6 m3 daily, can return to the water cycle. The city's total wastewater is 12,750,000 m3 per year and it is possible to prevent underground water harvesting with purification. Rainfall is another important resource never utilized in Boroujerd. The gable roof and those with more than 15 degrees gradient can be used to collect the rainwater in the high rainfall season. The total roofs are 136.13 ha and according to the average rainfall 0/454m, it can be the maximum use of this resource. The annual volume of precipitation for this city is 612612/45m3 which is significant. Supposedly, it could provide 3.6% of fresh water. Also, if the volume of sewage is considered for purification, the amount of available water source reaches 13362612/45m3 which can meet 60/74% of current water demand.Conclusion: Rainwater is not used as a natural resource in Borujerd city and flows into seasonal rivers as runoff. It can be said that harvesting rainwater is an opportunity to reduce water shortage in the future. Rainwater system transferred through the water pipelines and sewage system. It is possible to store rainfall and water remained after snow melts for dry seasons and its surplus can be used to supply. Also due to climate changes and agriculture in Borujerd city, a plan should be provided to reduce the use of water in the summer which is expected to be implemented shortly.

Three vital sources of Water-Energy-Food (WEF) are inextricably interrelated so that may also produce environmental impacts such as greenhouse gas emissions in production/delivery process. Therefore, green-house-gas emission control plays a key role in WEF nexus management. Effective planning and management of limited WEF resources to meet current and future socioeconomic demands for sustainable development is challenging. Nexus management for WEF security necessitates integrated tools that are useful for effective planning and management strategies and policies. Hence, the comprehensive tools should be used for identifying the trade-offs and interactions among various sectors of water, energy, and food. In this study, the nexus in the integrated management of the sources by optimisation method is investigated. Also, a hypothetical optimisation model of the water, energy, and food nexus is examined. This model is applied to quantitatively analyse the interrelationships and trade-offs among system components including energy supply, electricity generation, water supply-demand, food production, and mitigation of environmental impacts. The results demonstrated how these types of analyses could be helpful for decision makers and stakeholders to make cost-effective decisions for optimal WEF management.

Introduction: Implementing Integrated Water Resources Management requires balancing conflicting goals, and the effects on developing countries, which have a poor institutional capacity for change, and suggests a slower pace of integrated water resources management. The growing population of the world, especially in developing countries on one hand, and the need to provide food for this population, on the other hand, have not been the result of overreaching of resources. In this manner, the continuation of an untapped harvest of resources will endanger the sustainability of the region in the near future. Food production is largely depending on the water so that 70 to 80 percent of the water extracted from resources is consumed for irrigation, which is the reason why irrigated cultivation is regarded as inefficient consumers. Understanding how to extract, manage and consume water is the key to solve this problem. On the other hand, the health and safety of communities and agricultural production require energy. Principally in irrigation, it is not possible to extract water without consuming energy. Seeking to establish the goals of the third millennium of the United Nations, researchers have presented a variety of interdisciplinary approaches to achieve a dynamic balance in the food production and consumption of resources, most notably the approach of Water, Energy and Food (WEF) Nexus. Considering the limitation of the resources which is increasing day by day. This approach causes productivity increase by integrating water, energy and food cycles. Managing water, energy and food, despite the inherent systemic differences, are very similar, due to the close relationship between the system perspective and their interaction with each other, a new concept is now called a Nexus approach. This viewpoint describes the interconnected nature and the interplay of the three sectors.Materials and Methods: This research was carried out in Sefid-Rud dam Irrigation and Drainage Network. Sefid-Rud basin is located in the Guilan province, which is benefits from high precipitation, but factors such as dams construction in the upper reaches of the Sefid-Rud dam, the timely inconvenient precipitation and the lack of infrastructure to harvest the runoff, causes water shortages in the area. It is worth mentioning that 50% of the Guilan households have engaged in rice cultivation and more than 70% of the lands are located in the irrigation and drainage network of the Sefid-Rud dam. Hence, reducing rice cultivation in this region will have a great impact on economic and social life. Managing a Nexus approach to provide WEF security requires integrated and analytical approaches that can identify cross-sectoral exchanges, cost-effective planning, policy, and strategy management. Therefore, in this study, WEAP and LEAP software were used for managing water and food resources and managing the energy sector in Sefid-Rud irrigation and drainage network, respectively. Then, the integrated water resources management in the area was addressed by establishing a linkage between these two applications. In the first part of this study, the parameters output such as net water demand, water resources share for each demand node, unmet demand and the coverage regardless of the energy sector were compared.Results and Discussion: The results reveal that the annual water requirement of the Sefid-Rud irrigation and drainage network in 2016 with the NEXUS approach estimated about 8 million cubic meters more than the non-NEXUS approach. Agriculture is the most water-consuming node in the region and there are lots of dependencies on rice cultivation as the most water-consuming crop in the Guilan region. The next step aims to balance the supply and demand, the unmet demand at the agricultural section in the Foomanat, Central and East areas under various management scenarios. These scenarios are including dredging, increase the efficiency of transmission and distribution channels of irrigation and drainage networks, and eliminating unauthorized wells were evaluated.Conclusion: By examining the results of the applied management scenarios mentioned above, the 30% increase in the efficiency of transmission and distribution channels of irrigation and drainage networks in Sefid-Rud has the greatest impact on meeting the demand and reducing the unmet demands of triple areas. As a result of the 30% efficiency improvement scenario, decrease the agricultural demands of the Foomanat area, the central area, and the east (about 29.1, 84.5 and 62.1 million cubic meters, respectively) more than the reference scenario.

A mass-balance Ecopath model of coastal areas in the Caspian Sea has been constructed for a quantitative description of the trophic structure of the ecosystem. The model is used to estimate the important biological parameters and relationships among the different ecologically important groups. Twenty five species were used in the present analysis. The model is based on the data collected of Kilka fisheries, beach seining (Bony fish fisheries), and set Gillnet (Sturgeon Fisheries) and also dietary information. Total landings along the Iranian portion of southern Caspian coast reached 39647 t, including sturgeon (41 t), kilka (22873 t) and bony fishes (16733 t) in 2014. Two species of kilka (Common kilka and Anchovy) are important commercially in the Caspian Sea, together accounting in the past decade for > 60 % of the total catch, as well as being a crucial part of the food chain. The mean average trophic level was estimated at 3.17 by Ecopath software. In this research, the mean level were studied between eight species varied from 2.56 to 4.04, Sander lucioperca occupy the highest and the as vimba vimba was the lowest level. The ranges of total mortality varied from 0.5 to 2.56 per years. The food consumption rate was estimated about 101.56 per year Mixd trophic level index (MTI) showed small pelagic fishes as prey, have crucial role in feeding of pelagic predators population such as invasion of the ctenophore Mnemiopsis leidyi, bream fish and benthic fish such as sturgeon. In general, niche overlap was greater in more species such as Alburnus chalcoides, Rutilus rutilus, Clupeonella cultriventris, Rutilus kutum and M. leidyi who consumed large amounts of plankton. In conclusion small pelagic fish exert a major control on the trophic dynamics of the Caspian Sea ecosystems and constitute midtrophic-level populations.

A mass-balance Ecopath model of coastal areas in the Caspian Sea has been constructed for a quantitative description of the trophic structure of the ecosystem. The model is used to estimate the important biological parameters and relationships among the different ecologically important groups. Twenty five species were used in the present analysis. The model is based on the data collected of Kilka fisheries, beach seining (Bony fish fisheries), and set Gillnet (Sturgeon Fisheries) and also dietary information. Total landings along the Iranian portion of southern Caspian coast reached 39647 t, including sturgeon (41 t), kilka (22873 t) and bony fishes (16733 t) in 2014. Two species of kilka (Common kilka and Anchovy) are important commercially in the Caspian Sea, together accounting in the past decade for > 60 % of the total catch, as well as being a crucial part of the food chain. The mean average trophic level was estimated at 3.17 by Ecopath software. In this research, the mean level were studied between eight species varied from 2.56 to 4.04, Sander lucioperca occupy the highest and the as vimba vimba was the lowest level. The ranges of total mortality varied from 0.5 to 2.56 per years. The food consumption rate was estimated about 101.56 per year Mixd trophic level index (MTI) showed small pelagic fishes as prey, have crucial role in feeding of pelagic predators population such as invasion of the ctenophore Mnemiopsis leidyi, bream fish and benthic fish such as sturgeon. In general, niche overlap was greater in more species such as Alburnus chalcoides, Rutilus rutilus, Clupeonella cultriventris, Rutilus kutum and M. leidyi who consumed large amounts of plankton. In conclusion small pelagic fish exert a major control on the trophic dynamics of the Caspian Sea ecosystems and constitute midtrophic-level populations. | Iranian Fisheries Science Research Institute | Published

The approach of water, food and energy nexus is a comprehensive view of sustainability; and agriculture plays a key role in the use of these resources and food security. Considering that the identification of the indicators of the water, food and energy security nexus in the agricultural sector is the main criterion for checking the status of the deployment of these resources in order to establish security in the agricultural sector. The gap in this field has caused this article to compile and evaluate the indicators of the approach of water, food and energy security nexus in the agricultural sector. To achieve this goal, the method of qualitative content analysis was used, using MAXQDA 18 software and manual analysis. The research sample included 228 articles related to the research topic, which were published in national and international journals during the years 2007-2022. The findings showed; Water, food, and energy security have eight, fourteen, and ten indicators, respectively, which were categorized into four categories: access, availability, usability, and sustainability. According to the findings, we conclude that these indicators include the dimensions of sustainable development, including economic, social and environmental dimensions, and are interdependent. Therefore, these indicators are a comprehensive tool to measure the approach of water, food and energy nexus in the direction of sustainable development.