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The nexus concept has considerably matured during the past decade. Numerous literature reviews have significantly contributed to taking stock of the advancements in knowledge and tool development to improve science-policy support on highly connected and interdependent resources. However, literature reviews often focus on specific sector-based nexus concepts (such as water-energy-food nexus) and analyses (such as environmental assessment, technical tools, or the management and policy dimension). Therefore, a comprehensive understanding of the actual nexus and the resources it builds upon still needs to be improved. This paper aims to test the validity of the nexus construct for research and practice. Based on a systematic review of reviews, including 62 nexus-related review papers and subsequent consultation of some sixty nexus experts, we suggest a robust but flexible approach to advancing the Resource Nexus for research and practice. In doing so, the knowledge provided by nexus research may provide more substantial support to decision-makers when designing and implementing policies for the sustainable management of environmental resources.

Biological invasions, identified as one of the primary drivers of ecosystem change, present significant threats to biodiversity, economies, and human health. Globally, with 37,000 naturalized species and an annual cost of approximately 423 billion USD, addressing the issue of invasive species is increasingly urgent. This paper underscores the necessity of a transdisciplinary, global approach to preventing, managing, and eradicating invasive species. Our focus is on integrating the Nexus approach within the United Nations University (UNU) Sustainability Nexus AID (Analytics, Informatics and Data) Programme, which aligns with the 2030 Sustainable Development Goals (SDGs). This programme, currently encompassing various modules focused on different problems, leverages a range of AID tools to support policy, research, and management strategies. In the Biological Invasions module, we have curated a repository of 56 AID tools, categorized into six areas: Databases and Data Sources; Mapping, Monitoring, and Citizen Science Tools; Modeling and Prediction; Impact and Risk Assessment; Management and Control; and Research and Education. We discuss the utilities of these tools, their pivotal role in informed decision-making, and strategies for enhancing their adoption, functionality, and usability, including expanding documentation and user guidance into relevant local and official UN languages. The potential of these tools to bridge the science-policy gap and their crucial role in combating biological invasions are highlighted. Drawing a parallel to the COVID-19 pandemic, we emphasize the crucial need for proactive stakeholder engagement and international collaboration to effectively address this pressing environmental challenge.

The interaction between climate and groundwater forms a complex, coupled system that affects land‐atmosphere feedback processes and thus local climatic parameters. We propose an analytical framework that integrates local groundwater information and soil hydrophysical characteristics to identify regions with bidirectional (two‐way) coupling where groundwater is influenced by climatic factors (e.g., precipitation) and may affect local climate (e.g., through surface fluxes). The framework capitalizes on the concept of the evaporation characteristic length to quantify the hydraulic connection of groundwater to the soil surface. To evaluate the framework, we calculate the maximum depth of hydraulic connection (Dmax) between groundwater and the soil surface in Hamburg, Germany. For regions with Dmaxexceeding the groundwater depth (d), a bidirectional mode of coupling is defined, while Dmax< dimplies a unidirectional coupling mode. Our results indicate that climate driven evaporation changes potentially alter the coupling between groundwater and climate depending on soil texture. Moreover, soil hydraulic properties and shallow groundwater tables could play a crucial role in shifting land‐atmosphere feedback processes by influencing the coupling mode. This research provides insights into the groundwater‐climate interactions under various climatic conditions and soil textures which could contribute to sustainable land‐use management practices, particularly in regions characterized by bidirectional coupling. This study explores the hydraulic connection between climate and groundwater. We developed an analytical framework that combines local groundwater levels and soil hydrophysical characteristics to identify areas with potential two‐way climate‐groundwater interaction. In areas with bidirectional mode of coupling not only the groundwater is influenced by the climate (e.g., through precipitation), but also it may affect climatic parameters by influencing soil moisture and evapotranspiration. We employed the framework to calculate the maximum depth of hydraulic connection (Dmax) linking groundwater and climate in Hamburg, Germany. Results identify bidirectional coupling zones, where climate and groundwater can mutually influence each other. We found that changes in soil properties, evaporation dynamics, and groundwater levels affect the climate‐groundwater coupling thus shedding light on the impact of (shallow) groundwaters on land‐athmosphere feedback processes. A physically based framework was proposed to quantify effects of soil hydraulic properties on groundwater and climate interactionsSaturated hydraulic conductivity and groundwater levels are crucial for assessing the coupling modes in the study area (Hamburg, Germany)Combined effects of climatic parameters, soil properties and shallow groundwater influence the mode of coupling in Hamburg, Germany A physically based framework was proposed to quantify effects of soil hydraulic properties on groundwater and climate interactions Saturated hydraulic conductivity and groundwater levels are crucial for assessing the coupling modes in the study area (Hamburg, Germany) Combined effects of climatic parameters, soil properties and shallow groundwater influence the mode of coupling in Hamburg, Germany

Abstract:Who is right about the environmental commons: Hardin or Ostrom? This paper recommends using the views of Garrett Hardin and Elinor Ostrom in a complementary manner, arguing that they are not mutually exclusive in complex, evolving, multi-shot, and never-ending environmental common-pool resource management problems. In these problems, noncooperative (Hardinian) and cooperative (Ostromian) tendencies, behavior, and institutions can coexist while their levels of dominance continuously change. To determine their dominance levels and potential viability over time, the paper proposes considering propensity to cooperate as a variable that is dependent on societies’ level of development.

The present paper tries to identify the optimal size of a wind farm using North European data. An empirical analysis of 61 sites constructed between 2004 and 2014 suggests that economies-of-scale are highly heterogeneous across on-shore and off-shore projects. A Varying Coefficient Model captures such diversity by making the impact of the farm site on the amount of its potential capacity a non-linear function of the number of installed turbines. The resulting scale elasticities suggest that small on-shore farms have a bigger per-turbines output than off-shore ones, while the opposite is true for big projects.

Being the second-largest country in the Middle East, Iran has a long history of civilisation during which several dynasties have been overthrown and established and health-related structures have been reorganised. Iran has had the replacement of traditional practices with modern medical treatments, emergence of multiple pioneer scientists and physicians with great contributions to the advancement of science, environmental and ecological changes in addition to large-scale natural disasters, epidemics of multiple communicable diseases, and the shift towards non-communicable diseases in recent decades. Given the lessons learnt from political instabilities in the past centuries and the approaches undertaken to overcome health challenges at the time, Iran has emerged as it is today. Iran is now a country with a population exceeding 80 million, mainly inhabiting urban regions, and has an increasing burden of non-communicable diseases, including cardiovascular diseases, hypertension, diabetes, malignancies, mental disorders, substance abuse, and road injuries.

We develop a game theoretic model of the role of foresight in games involving users interacting over a public good. Previous research in this area has applied game theory to understand social dilemmas and inform policy initiatives. However, considerations of the “evolving structure” of natural resource games over time and agents' planning horizon raises the complexity of game analysis substantially and has often been overlooked. We analyze a simple model of an irrigation system shared by two users and consider how players will act under different levels of foresight. Without foresight into game changes over time, players are blind to the fact that they are in a game of chicken. We model agents with foresight by interconnecting games across time and show how this creates opportunities for “strategic loss” early on, allowing players with foresight to reduce total costs. High future costs can thus be avoided with foresight if the rising costs of inaction are made apparent. We consider the effect of discounting and differences between players to provide policy recommendations regarding incentives for foresight. Myopic stakeholders allow public goods to deteriorate not realizing they are in a long‐term game of chickenForesight allows them to resolve conflicts earlier and cheaper through strategic lossThe incentive for foresight is ambiguous, depending on differentiation between players

Sustainable green chemistry depends on technically feasible, cost-effective and socially acceptable decisions by regulators, industry and the wider community. The discipline needs to embrace a new suite of tools and train proponents in their use. We propose a set of tools that will bridge the gap between technical feasibility and efficiency on one hand, and social preferences and values on the other. We argue that they are indispensable in the next generation of regulators and chemistry industry proponents.

ABSTRACTEngagement between investors and corporate boards has been suggested as a pathway to mitigate stranded asset and climate change risks. Debate is ongoing as to whether divestment or active ownership strategies are more appropriate to deliver long-term value and environmental sustainability. The paper tests the effectiveness of owner engagement strategies by studying the conditions for cooperation between investors and their companies. Characteristics of investors and companies are modelled in game theoretic frameworks, informed by semi-structured interviews with professionals from the energy and finance industries, and academia, NGO, and regulatory sectors. Conditions for mutual cooperation between investors and companies are characterized as prisoners’ dilemmas. A number of parameters are examined for their impact on the development of sustained cooperative equilibria, including: the benefits and costs of cooperation; the degree of strategic foresight; individual discount factors; and mutual history. Challenges in the formation of investor coalitions are characterized and solutions are proposed.

Optimal risk-based levee designs are usually developed for economic efficiency. However, in river systems with multiple levees, the planning and maintenance of different levees are controlled by different agencies or groups. For example, along many rivers, levees on opposite riverbanks constitute a simple leveed river system with each levee designed and controlled separately. Collaborative planning of the two levees can be economically optimal for the whole system. Independent and self-interested landholders on opposite riversides often are willing to separately determine their individual optimal levee plans, resulting in a less efficient leveed river system from an overall society-wide perspective (the tragedy of commons). We apply game theory to simple leveed river system planning where landholders on each riverside independently determine their optimal risk-based levee plans. Outcomes from noncooperative games are analyzed and compared with the overall economically optimal outcome, which minimizes net flood cost system-wide. The system-wide economically optimal solution generally transfers residual flood risk to the lower-valued side of the river, but is often impractical without compensating for flood risk transfer to improve outcomes for all individuals involved. Such compensation can be determined and implemented with landholders' agreements on collaboration to develop an economically optimal plan. By examining iterative multiple-shot noncooperative games with reversible and irreversible decisions, the costs of myopia for the future in making levee planning decisions show the significance of considering the externalities and evolution path of dynamic water resource problems to improve decision-making. Game theory can provide solutions and guidance for conflicting leveed river system planningNoncooperation between self-interested individuals leads to inefficient system-wide outcomesCompensation or authority is often needed for economically efficient leveed river system planning

Despite having a more advanced water management system than most Middle Eastern countries, similar to the other countries in the region, Iran is experiencing a serious water crisis. The government blames the current crisis on the changing climate, frequent droughts, and international sanctions, believing that water shortages are periodic. However, the dramatic water security issues of Iran are rooted in decades of disintegrated planning and managerial myopia. Iran has suffered from a symptom-based management paradigm, which mainly focuses on curing the problem symptoms rather than addressing the main causes. This paper reviews the current status of water resources in Iran and recognizes three major causes for the current water crisis: (1) rapid population growth and inappropriate spatial population distribution; (2) inefficient agriculture sector; and (3) mismanagement and thirst for development. The country is faced with serious challenges in the water sector, including but not limited to rising water demand and shortage, declining groundwater levels, deteriorating water quality, and increasing ecosystem losses. If immediate actions are not taken to address these issues, the situation could become more tragic in the near future. The paper suggests some crisis exit strategies that need to be immediately adopted to secure sustainable water resources, if Iran does not want to lose its international reputation for significant success in water resources management over thousands of years in an arid area of the world.

In this paper, a simple neuro-controller for power systems is presented. The controller performs the function of the terminal voltage control. By representing the proposed neuro-controller in s-domain, its parameters can be obtained analytically to ensure system stability. Results of simulation studies on a nonlinear third order generator model with the proposed neuro-controller using calculated parameters are given. Results of simulation studies demonstrate the effectiveness of this simple neuro-controller.

Design of an optimal nonlinear state feedback voltage regulator for power systems is proposed in this paper. In order to obtain the nonlinear control law the Hamilton-Jacobi-Belman (HJB) equation is solved using Taylor series expansion of its nonlinear terms. The performance of the proposed controller in a single machine-infinite bus power system is simulated and the advantages of the nonlinear feedback controllers in some grounds like increasing the fault tolerance and domain of validity of the close-loop system are investigated. Also, the advantages of the proposed controller in the presence of some disturbances are shown. Simulation results reveal the effectiveness of the proposed controller.

Traditional, mainstream definitions of drought describe it as deficit in water‐related variables or water‐dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision‐makers. Here, we argue that within coupled human‐water systems, drought must be defined and understood as a processas opposed to a productto help better frame and describe the complex and interrelated dynamics of both natural and human‐induced changes that define anthropogenic droughtas a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions and activities, and altered micro‐climate conditions due to changes in land and water management. This definition considers the full spectrum of dynamic feedbacks and processes (e.g., land‐atmosphere interactions and water and energy balance) within human‐nature systems that drive the development of anthropogenic drought. This process magnifies the water supply demand gap and can lead to water bankruptcy, which will become more rampant around the globe in the coming decades due to continuously growing water demands under compounding effects of climate change and global environmental degradation. This challenge has de facto implications for both short‐term and long‐term water resources planning and management, water governance, and policymaking. Herein, after a brief overview of the anthropogenic drought concept and its examples, we discuss existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon. This article reviews research and progress on the notion of anthropogenic droughtbroadly defined as drought events caused or intensified by human activities. Most commonly used drought definitions are based on deficit in hydrologic/meteorologic drivers such as precipitation and runoff. Within coupled human‐water systems, however, drought must be defined and understood as the complex and interrelated dynamics of both natural and human‐induced changes. This anthropogenic droughtdefinition considers the full spectrum of dynamic feedbacks and processes (e.g., land‐atmosphere interactions and water and energy balance) within human‐nature systems. Ideally, anthropogenic droughtand the corresponding human interactions should be incorporated in models that include land‐atmosphere interactions, water balance, and energy balance. In this article, we review existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon. Anthropogenic droughtis primarily governed by the joint impacts of natural renewable water variability, climate change, and human decisionsAnthropogenic droughtand water bankruptcy will become more ubiquitous under current development and climate change trajectoriesIdeally, human interactions should be incorporated in models that include land‐atmosphere interactions, water balance and energy balance Anthropogenic droughtis primarily governed by the joint impacts of natural renewable water variability, climate change, and human decisions Anthropogenic droughtand water bankruptcy will become more ubiquitous under current development and climate change trajectories Ideally, human interactions should be incorporated in models that include land‐atmosphere interactions, water balance and energy balance

Beneficiaries of common pool resources (CPRs) may select available noncooperative and regulatory exogenous institutions for managing the resource, as well as cooperative management institutions. All these institutions may increase the long‐term gains, prolong the life of the resource, and help to escape the tragedy of the commons trap. Cooperative game theory approaches can serve as the backbone of cooperative CPR management institutions. This paper formulates and applies several commonly used cooperative game theoretic solution concepts, namely, the core, Nash‐Harsanyi, Shapley, and nucleolus. Through a numerical groundwater example, we show how CPR users can share the gains obtained from cooperation in a fair and efficient manner based on these cooperative solution concepts (management institutions). Although, based on their fairness rationales, various cooperative management institutions may suggest different allocations that are potentially acceptable to the users, these allocation solutions may not be stable as some users may find them unfair. This paper discusses how different methods, such as application of the plurality rule and power index, stability index, and propensity to disrupt concepts, can help identify the most stable and likely solutions for enforcing cooperation among the CPR beneficiaries. Furthermore, how the noncooperative managerial characteristics of the CPR users can affect the stability and acceptability of the different cooperative CPR management institutions is discussed, providing valuable policy insights for cooperative CPR management at community levels. Suggesting various cooperating institutions for managing CPRsApplication of cooperative institutions for sustainable CPR managementEvaluating the effects of cooperative institutions on CPRs and their users