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Cooperative game theory provides an appropriate framework to assess the likelihood of conflict resolution, encourage cooperation among parties, and determine each party's share in resource sharing conflicts. In calculating the fair and efficient allocation of the incremental benefits of cooperation, cooperative game theory methods often do not consider the exogenous bargaining powers of the players based on factors, that are external to the game, such as their political, economic, and military powers. This study reformulates three well-known cooperative game theory methods, namely, Nash-Harsanyi, Shapley, and Nucleolus, to account for the exogenous bargaining powers of the players in cooperative games. Using the Caspian Sea international conflict as an example, this paper shows how the negotiators' exogenous bargaining power can change the outcome of resource sharing games. The proposed weighted cooperative game theory approach can help determine practical resolutions for real-world conflicts in which the exogenous powers of players can have a significant influence on the outcome of negotiations. [ABSTRACT FROM AUTHOR]

Problems have a high rank in decision making when they are both urgent and important. Accordingly, water has not earned the attention it deserves in public policy agenda because under normal circumstances it is not viewed as an urgent matter in the eyes of the public and politicians. By creating a sense of urgency, extreme events such as droughts, floods, conflicts, and migrations can create opportunities for implementing some essential policy reforms that would be politically costly otherwise. So, despite their high short-term costs, extreme natural and societal events have the potential to increase the resilience of water systems in the long run. It is argued here that the societal and political sense of urgency about water must be promoted through public outreach and information dissemination. Otherwise, for useful reforms and long-term improvements, we will rely on costly and risky extreme events that sometimes have the potential to fully collapse the human-natural system-of-systems. [ABSTRACT FROM AUTHOR]

Highlights • Techno-economic modelling of PV/battery systems. • Novel approach developed to assess solar PV/battery technologies. • Grid-connected PV systems identified to have great potential. • Feasibility of PV/battery systems possible with >90% reduction in battery costs. • Further research and innovation in battery technologies necessary. Abstract Oman is a country characterised by high solar availability, yet very little electricity is produced using solar energy. As the residential sector is the largest consumer of electricity in Oman, we develop a novel approach, using houses in Muscat as a case study, to assess the potential of implementing roof-top solar PV/battery technologies, that operate without recourse to the electricity grid. Such systems target the complete decarbonisation of electricity demand per household and are defined in this study as grid-independent systems. The approach adopted starts with a technical assessment of grid-independent systems that evaluates the characteristics of the solar panel and the battery facility required to provide grid-independence. This is then compared to a similar grid-connected system and any techno-economic targets necessary to enhance the feasibility of residential roof-top PV systems in Muscat are identified. Such an analysis was achieved through developing a detailed techno-economic mathematical model describing four sub-systems; the solar panel DC source, the grid-independent sub-system, the grid-connected sub-system and the economic sub-system. The model was implemented in gPROMS and uses real hourly weather and climate conditions matched with real demand data, over a simulated period of 20 years. The results indicate that, in the context of the system studied, grid-independent PV systems are not feasible. However, combined with a sufficiently high electricity price, grid-independent systems can become economically feasible only with significant reductions in battery costs (>90% reductions). [ABSTRACT FROM AUTHOR]

The feasibility of groundwater monitoring was investigated by a case study on adopting smart water meters to measure groundwater extraction at individual farms and a centralized online information management system to measure collective aquifer water extraction. Benefits of optimal groundwater management was estimated using hydro-economic models that simulate, for a 70-year period, private and social optimality, taking into account the effects of seawater intrusion on groundwater salinity. A Bayesian inference system was used as an interface between a dynamic programming model and MODFLOW groundwater simulation model. The case study’s cost data were scaled-up to the aquifer level and compared to the incremental benefits between private and socially optimal water extraction. The results showed that the Net Present Value of measuring and monitoring groundwater extraction using smart water meters as $790 million ($1332/ha/year) with an Internal Rate of Return of 93%. The sustainable use of the aquifer results to a reduction of the cropped area by 10%, a reduction of the groundwater extraction by 20%, a change in the crop mix, and 42% of the least-efficient farms exiting farming. The exiting farmers could convert farm lands to other land uses such as residential, urban, industrial land use, with adequate facilitation provided by the government. The impact of change of groundwater management strategy on the arid ecology with reduction in tree cover is noted. [ABSTRACT FROM AUTHOR]

In practice, selecting an energy project for development requires balancing criteria and competing stakeholder priorities to identify the best alternative. Energy source selection can be modeled as multi-criteria decision-maker problems to provide quantitative support to reconcile technical, economic, environmental, social, and political factors with respect to the stakeholders' interests. Decision making among these complex interactions should also account for the uncertainty present in the input data. In response, this work develops a stochastic decision analysis framework to evaluate alternatives by involving stakeholders to identify both quantitative and qualitative selection criteria and performance metrics which carry uncertainties. The developed framework is illustrated using a case study from Fairbanks, Alaska, where decision makers and residents must decide on a new source of energy for heating and electricity. We approach this problem in a five step methodology: (1) engaging experts (role players) to develop criteria of project performance; (2) collecting a range of quantitative and qualitative input information to determine the performance of each proposed solution according to the selected criteria; (3) performing a Monte-Carlo analysis to capture uncertainties given in the inputs; (4) applying multi-criteria decision-making, social choice (voting), and fallback bargaining methods to account for three different levels of cooperation among the stakeholders; and (5) computing an aggregate performance index (API) score for each alternative based on its performance across criteria and cooperation levels. API scores communicate relative performance between alternatives. In this way, our methodology maps uncertainty from the input data to reflect risk in the decision and incorporates varying degrees of cooperation into the analysis to identify an optimal and practical alternative. [ABSTRACT FROM AUTHOR]

Iran is currently experiencing serious water problems. Frequent droughts coupled with over-abstraction of surface and groundwater through a large network of hydraulic infrastructure and deep wells have escalated the nation's water situation to a critical level. This is evidenced by drying lakes, rivers and wetlands, declining groundwater levels, land subsidence, water quality degradation, soil erosion, desertification and more frequent dust storms. This paper overviews the major drivers of Iran's water problems. It is argued that while climatic changes and economic sanctions are commonly blamed as the main drivers of water problems, Iran is mainly suffering from a socio-economic drought—i.e. "water bankruptcy," where water demand exceeds the natural water supply. In theory, this problem can be resolved by re-establishing the balance between water supply and demand through developing additional sources of water supply and implementing aggressive water demand reduction plans. Nevertheless, the current structure of the water governance system in Iran and the absence of a comprehensive understanding of the root causes of the problem leave minimal hope of developing sustainable solutions to Iran's unprecedented water problems. [ABSTRACT FROM AUTHOR]

Historically, the U.S. waste collection fleet was dominated by diesel-fueled waste collection vehicles (WCVs); the growing need for sustainable waste collection has urged decision makers to incorporate economically efficient alternative fuels, while mitigating environmental impacts. The pros and cons of alternative fuels complicate the decisions making process, calling for a comprehensive study that assesses the multiple factors involved. Multi-criteria decision analysis (MCDA) methods allow decision makers to select the best alternatives with respect to selection criteria. In this study, two MCDA methods, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW), were used to rank fuel alternatives for the U.S. waste collection industry with respect to a multi-level environmental and financial decision matrix. The environmental criteria consisted of life-cycle emissions, tail-pipe emissions, water footprint (WFP), and power density, while the financial criteria comprised of vehicle cost, fuel price, fuel price stability, and fueling station availability. The overall analysis showed that conventional diesel is still the best option, followed by hydraulic-hybrid WCVs, landfill gas (LFG) sourced natural gas, fossil natural gas, and biodiesel. The elimination of the WFP and power density criteria from the environmental criteria ranked biodiesel 100 (BD100) as an environmentally better alternative compared to other fossil fuels (diesel and natural gas). This result showed that considering the WFP and power density as environmental criteria can make a difference in the decision process. The elimination of the fueling station and fuel price stability criteria from the decision matrix ranked fossil natural gas second after LFG-sourced natural gas. This scenario was found to represent the status quo of the waste collection industry. A sensitivity analysis for the status quo scenario showed the overall ranking of diesel and fossil natural gas to be more sensitive to changing fuel prices as compared to other alternatives. [ABSTRACT FROM AUTHOR]

Collaborative negotiation has been widely used for developing water policy. Nevertheless, a serious lacuna remains in the understanding of the factors that determine whether the negotiators in this bargaining process will be able to reach agreement. This paper argues that the literature has focused on the process that is followed in negotiations, to the virtual exclusion of the substance of the issues that are to be resolved. As a consensus can only be reached concerning a change in policy if each party receives compensation for the concessions that it makes, a precondition for collaborative negotiation is that each party must have control over some asset that it can "trade" with the other parties. When this condition is met, it can be said that the process has "substance." The authors identify a number of situations in which negotiations over water policy may possess this characteristic. However, they also argue that there is a large set of cases in which positive net gains are available, but in which at least one party lacks control over an asset that can be exchanged. In these cases, a number of government policies are investigated that could provide stakeholders with the necessary tradable goods and, therefore, could impart substance to the process. Many situations still remain, however, in which collaboration will lack substance, and stakeholders can be expected either to seek alternative means for pursuing their goals or to waste their effort in endless bargaining. [ABSTRACT FROM AUTHOR]

Summary Reservoir systems with multiple operators can benefit from coordination of operation policies. To maximize the total benefit of these systems the literature has normally used the social planner’s approach. Based on this approach operation decisions are optimized using a multi-objective optimization model with a compound system’s objective. While the utility of the system can be increased this way, fair allocation of benefits among the operators remains challenging for the social planner who has to assign controversial weights to the system’s beneficiaries and their objectives. Cooperative game theory provides an alternative framework for fair and efficient allocation of the incremental benefits of cooperation. To determine the fair and efficient utility shares of the beneficiaries, cooperative game theory solution methods consider the gains of each party in the status quo (non-cooperation) as well as what can be gained through the grand coalition (social planner’s solution or full cooperation) and partial coalitions. Nevertheless, estimation of the benefits of different coalitions can be challenging in complex multi-beneficiary systems. Reinforcement learning can be used to address this challenge and determine the gains of the beneficiaries for different levels of cooperation, i.e., non-cooperation, partial cooperation, and full cooperation, providing the essential input for allocation based on cooperative game theory. This paper develops a game theory–reinforcement learning (GT–RL) method for determining the optimal operation policies in multi-operator multi-reservoir systems with respect to fairness and efficiency criteria. As the first step to underline the utility of the GT–RL method in solving complex multi-agent multi-reservoir problems without a need for developing compound objectives and weight assignment, the proposed method is applied to a hypothetical three-agent three-reservoir system. [ABSTRACT FROM AUTHOR]

This paper develops a novel service request sequence optimization model for tower crane operation efficiency improvement. The suggested model uses integer programming and modifies the classical Traveling Salesman Problem (TSP) formulation for optimizing construction tower crane operations. Numerical examples demonstrate that the application of the developed optimization model can result in 25–45% saving in the total travel time of the tower crane depending on the number of simultaneous requests. [ABSTRACT FROM AUTHOR]

This paper evaluates the proposed alternatives for sharing the Caspian Sea from the social planner's or systems-level perspective with respect to the stakeholders' utilities from the oil and natural gas resources of the sea. Different multi-criteria decision-making methods, namely dominance, maximin, lexicography, simple additive weighting, and TOPSIS are applied to determine the social planner's ranking of these alternatives. Results suggest the Condominium governance regime as the most promising division method. Bankruptcy rules and cooperative game theory methods can be considered as the other socially optimal resolutions to the conflict over sharing the Caspian Sea energy resources among its five littoral countries. Consideration of these methods in negotiations may help with resolving the existing deadlock, which has been in place for two decades. [ABSTRACT FROM AUTHOR]

Highlights: [•] Addressing the major gap in previous climate change and hydropower research in California. [•] Simultaneous evaluation of climate change effects on high-elevation hydropower supply and pricing. [•] Estimating climate warming effects on high-elevation hydropower operations in California. [ABSTRACT FROM AUTHOR]

Water allocation is a growing concern in a developing world where limited resources like fresh water are in greater demand by more parties. Negotiations over allocations often involve multiple groups with disparate social, economic, and political status and needs, who are seeking a management solution for a wide range of demands. Optimization techniques for identifying the Pareto-optimal (social planner solution) to multi-criteria multi-participant problems are commonly implemented, although often reaching agreement for this solution is difficult. In negotiations with multiple-decision makers, parties who base decisions on individual rationality may find the social planner solution to be unfair, thus creating a need to evaluate the willingness to cooperate and practicality of a cooperative allocation solution, i.e., the solution's stability. This paper suggests seeking solutions for multi-participant resource allocation problems through an economics-based power index allocation method. This method can inform on allocation schemes that quantify a party's willingness to participate in a negotiation rather than opt for no agreement. Through comparison of the suggested method with a range of distance-based multi-criteria decision making rules, namely, least squares, MAXIMIN, MINIMAX, and compromise programming, this paper shows that optimality and stability can produce different allocation solutions. The mismatch between the socially-optimal alternative and the most stable alternative can potentially result in parties leaving the negotiation as they may be too dissatisfied with their resource share. This finding has important policy implications as it justifies why stakeholders may not accept the socially optimal solution in practice, and underlies the necessity of considering stability where it may be more appropriate to give up an unstable Pareto-optimal solution for an inferior stable one. Authors suggest assessing the stability of an allocation solution as an additional component to an analysis that seeks to distribute water in a negotiated process. [Copyright &y& Elsevier]

Abstract: Post-Soviet legal governance regime of Caspian Sea – the largest inland body of water on earth – remains a source of conflict among the five coastal states of Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan. Although different division methods have been suggested for sharing the sea and its valuable resources, the actual gain of the countries is unclear as the proposed methods focus either on the oil and gas or the areal share of the parties. The Caspian Sea Negotiation Support System (Caspian Sea NSS) is developed in this study to delineate optimal boundaries for sharing the sea through simultaneous consideration of the countries' areal and resource shares under different sharing methods. This NSS is a complex optimization model, with a solver engine that provides reliable results with a reasonable computational effort using a heuristic method. The model is run under different division scenarios to evaluate the sensitivity of each party's gain and locations of nautical boundaries to the division rules and the economic values of the resources. Results show a high sensitivity of the optimal nautical boundaries to the division rules and an indirect relationship between the allocated area and resource shares. The findings highlight the necessity for considering utility shares in negotiations as opposed to adopting areal division rules which ignore the utilities and might result in unfair resource allocation. The main policy implication of the study is that clarification of the countries' resource and areal gain under any suggested legal regime for governing the Caspian Sea is essential to the success of the negotiations. [Copyright &y& Elsevier]

Abstract: In a recent article in this journal entitled “Game Theory and Climate Diplomacy”, DeCanio and Fremstad (2013) provide an interesting treatment of a range of simple game theoretic characterizations of international climate negotiations. The authors use the Nash and Maxi-min stability definitions to analyze 25 two-by-two ordinal games, which they recognize as “possible game-theoretic characterizations of climate negotiations between two players (e.g., Great Powers or coalitions of states)”. The authors' main conclusion that the Prisoner's Dilemma might not be the best description of climate negotiations game is consistent with the findings of others who have studied two-by-two conflicts over natural commons (Bardhan, 1993; Madani, 2010; Sandler, 1992; Taylor, 1987). Nevertheless, given the importance of the climate change issue, as well as the potential effects of our actions on the state of the environment and the well-being of future generations, I would like to address some gaps in their analysis, which result in it having limited usefulness for policy purposes. Of course, all models are simplified representations of reality, full of limitations. “Essentially, all models are wrong, but some are useful” (Box and Draper, 1987). So, “the practical question is how wrong do they have to be to not be useful” (Box and Draper, 1987). Models' limitations need to be carefully considered when interpreting them or applying their results to policy but some models are too simple to provide useful policy advice. [Copyright &y& Elsevier]

California's Sacramento-San Joaquin Delta is the major hub of California's water supply system and is central to the ecosystem of many native threatened and endangered species. Conflicts over the Delta have evolved over more than a century. This paper traces changes in this conflict in game-theoretic terms, with its implications for the region's physical and ecological decline and governance. The Delta is not a zero-sum problem and win-win resolutions may exist if stakeholders cooperate. Game theory provides some insights on the potential for win-win solutions. The Delta problem has had a Prisoner's Dilemma structure, in which stakeholder self-interest makes cooperation unlikely within a reasonable time frame. However, the core of the Delta conflict is changing as the unsustainable future becomes more widely understood. Today's Delta problem has characteristics of a Chicken game, where cooperation is in everyone's interest, but it is unlikely because parties deviating from the status quo are likely to bear more of the costs of a long-term solution. The State of California may become the victim (or chicken) of the Delta game, bearing the greatest costs, if it continues to rely on leaving parties to develop voluntary cooperative solutions without a sufficient mechanism for enforcing cooperation. [ABSTRACT FROM AUTHOR]

As demands for limited natural resources increase, developing management institutions that ensure the sustainability of such resources is essential. Many natural resources are Common Pool Resources (CPRs), managed under different non-cooperative, cooperative, and externally imposed management frameworks. While early studies of non-cooperative CPR management suggest inevitable “tragedy of the commons,” here we discuss how users can avoid tragic outcomes by changing their decision making rationales and exploitation strategies even in a non-cooperative environment. This paper introduces and compares various types of non-cooperative institutions that are available to manage CPRs. These management institutions are then applied, using a numerical groundwater exploitation example, to determine how different planning variables are affected by the choice of management institution. Results indicate that CPR users can improve their gains by considering the externalities and developing long-term exploitation plans, as opposed to short-term plans with no consideration of externalities that result in rapid exhaustion of the resource and lead to the so-called “tragedy of the commons.” [Copyright &y& Elsevier]

Abstract: Game theory provides a useful framework for studying Multi-Criteria Decision Making problems. This paper suggests modeling Multi-Criteria Decision Making problems as strategic games and solving them using non-cooperative game theory concepts. The suggested method can be used to prescribe non-dominated solutions and also can be used as a method to predict the outcome of a decision making problem. Non-cooperative stability definitions for solving the games allow consideration of non-cooperative behaviors, often neglected by other methods which assume perfect cooperation among decision makers. To deal with the uncertainty in input variables a Monte-Carlo Game Theory (MCGT) approach is suggested which maps the stochastic problem into many deterministic strategic games. The games are solved using non-cooperative stability definitions and the results include possible effects of uncertainty in input variables on outcomes. The method can handle multi-criteria multi-decision-maker problems with uncertainty. The suggested method does not require criteria weighting, developing a compound decision objective, and accurate quantitative (cardinal) information as it simplifies the decision analysis by solving problems based on qualitative (ordinal) information, reducing the computational burden substantially. The MCGT method is applied to analyze California’s Sacramento-San Joaquin Delta problem. The suggested method provides insights, identifies non-dominated alternatives, and predicts likely decision outcomes. [Copyright &y& Elsevier]

Abstract: Cooperative game theory solutions can provide useful insights into how parties may use water and environmental resources and share any benefits of cooperation. Here, a method based on Nash and Nash–Harsanyi bargaining solutions is developed to explore the Federal Energy Regulatory Commission (FERC) relicensing process, in which owners of non-federal hydropower projects in the United States have to negotiate their allowable operations, with other interest groups (mainly environmental). Linkage of games to expand the feasible solution range and the “strategic loss” concept are discussed and a FERC relicensing bargaining model is developed for studying the bargaining stage (third stage) of the relicensing process. Based on the suggested solution method, how the lack of incentive for cooperation results in long delay in FERC relicensing in practice is explained. Further, potential effects of climate change on the FERC relicensing are presented and how climate change may provide an incentive for cooperation among the parties to hasten the relicensing is discussed. An “adaptive FERC license” framework is proposed, based on cooperative game theory, to improve the performance and adaptability of the system to future changes with no cost to the FERC, in face of uncertainty about future hydrological and ecological conditions. [ABSTRACT FROM AUTHOR]

California's hydropower system is composed of high and low elevation power plants. There are more than 150 high-elevation power plants, at elevations above 1,000 feet (300 m). Most have modest reservoir storage capacities, but supply roughly 74% of California's in-state hydropower. The expected shift of runoff peak from spring to winter due to climate warming, resulting in snowpack reduction and increased snowmelt, might have important effects on power generation and revenues in California. The large storage capacities at low-elevation power plants provide flexibility to operations of these units under climate warming. However, with climate warming, the adaptability of the high-elevation hydropower system is in question as this system was designed to take advantage of snowpack, a natural reservoir. With so many high-elevation hydropower plants in California, estimation of climate warming effects by conventional simulation or optimization methods would be tedious and expensive. An Energy-Based Hydropower Optimization Model (EBHOM) was developed to facilitate practical climate change and other low-resolution system-wide hydropower studies, based on the historical generation data of 137 high-elevation hydropower plants for which the data were complete for 14 years. Employing recent historical hourly energy prices, the model was used to explore energy generation in California for three climate warming scenarios (dry warming, wet warming, and warming-only) over 14 years, representing a range of hydrologic conditions. The system is sensitive to the quantity and timing of inflows. While dry warming and warming-only climate changes reduce average hydropower revenues, wet warming could increase revenue. Re-operation of available storage and generation capacities help compensate for snowpack losses to some extent. Storage capacity expansion and to a lesser extent generation capacity expansion both increase revenues, although such expansions might not be cost-effective. [ABSTRACT FROM AUTHOR]

Summary: Managing water resources systems usually involves conflicts. Behaviors of stakeholders, who might be willing to contribute to improvements and reach a win–win situation, sometimes result in worse conditions for all parties. Game theory can identify and interpret the behaviors of parties to water resource problems and describe how interactions of different parties who give priority to their own objectives, rather than system’s objective, result in a system’s evolution. Outcomes predicted by game theory often differ from results suggested by optimization methods which assume all parties are willing to act towards the best system-wide outcome. This study reviews applicability of game theory to water resources management and conflict resolution through a series of non-cooperative water resource games. The paper illustrates the dynamic structure of water resource problems and the importance of considering the game’s evolution path while studying such problems. [Copyright &y& Elsevier]

[Display omitted] • A water quality improvement using selective withdrawal and RDM. • An XLRM was used to make a comprehensive framework. • The RDM was used to classify pareto optimal solutions and find vulnerable ones. • The vulnerable outlets and ratio release were discovered by scenario discovery. In arid locations such as Oman, improving the quality of water released from a reservoir can be daunting. This is particularly true for Wadi Dayqah Dam, which struggles to provide sufficient, high-quality water for downstream needs. The study's objective was to establish more reliable operational guidelines, as well as identify vulnerable outlets and release ratios. To do so, a multi-objective optimization algorithm (NSGA-II) was combined with a selective withdrawal approach, using CE-QUAL-W2 and an Artificial Neural Network to simulate water quality in a reservoir. Then, a Robust Decision Making (RDM) approach was utilized to diagnose solutions that maintain acceptable water quality according to users' requirements. Finally, scenario discovery models (Patient Rule Induction Method (PRIM) and Classification and Regression Tree (CART)) were used to calculate vulnerable outlets and release ratios based on the established threshold. The study adopted an XLRM framework to manage a proposed model under climate change scenarios and specify the effects of involved factors. XLRM stands for eXogenous factors, Levers used by the policy-makers, Relationships between L and X, and Measurement matrix to evaluate scenarios. This study found that a higher-quality reservoir release correlated with more activated outlets and decreased pollutant concentration. Evaluating robust solutions showed that vulnerability increased under scenarios with lower annual rainfall, and water released from low and mid-level outlets was more vulnerable than that from the surface. To enhance operational stability and reduce vulnerability, the suggestions advocate for a strategic approach in releasing varying water ratios from outlets situated at different levels. Specifically, the proposal emphasizes the controlled release of both smaller and larger volumes of water from outlets positioned at lower and higher levels within the dam structure, respectively. This deliberate variation in water release aims to bolster the overall resilience of the operational framework, contributing to a more robust and reliable system. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The article focuses on water resources systems analysis, based on the result of a panel discussion held at the Environmental Water Resources Institute (EWRI) Congress in Cincinnati, Ohio in May 2013. Topics include the tools and techniques to identify components of a system, the science of defining water-based problems and the role of other branches of science in evaluating the system. Also discussed are computational capabilities, the use of satellite, sensor, automation and networking.

The authors discuss issues to be considered by water professionals for sustainability monitoring and assessment. They describe sustainable development as a quality issue and a process. They recommend developing processes and tools that help promote sustainability and practicing participatory planning and collaborative, trust-based decision-making based on a common sense of urgency.

The article offers information on importance of proactively addressing aging and problematic dams. Topics discussed include need a scientific and legal framework in place to evaluate if and when dam removal is required; role of Environmental impact assessment in dam rehabilitation and removal decisions; and need to address socio-economic, technological, and regulatory barriers to dam maintenance.

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 process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human‐induced changes that define anthropogenic drought as 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. Plain Language Summary: This article reviews research and progress on the notion of anthropogenic drought broadly 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 drought definition 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 drought and 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. Key Points: Anthropogenic drought is primarily governed by the joint impacts of natural renewable water variability, climate change, and human decisionsAnthropogenic drought and 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 [ABSTRACT FROM AUTHOR]

There is mounting evidence that human-made climate changes do project onto the natural modes of climate variability. As a result, hydro-climatic extreme events have become more intense and more frequent in the last decades. Yet, unraveling the role of climate change and climate variability in the occurrence of extreme events remains poorly known. Such information is critical to assess and manage disaster risks and improve adaptation and mitigation strategies to decrease the damages and costs to society. This study seeks to tease out the impact of anthropogenic climate change from natural climate variability on daily extreme rainfall events at 263 stations in Europe over an approximately century-long period from 1925 to 2015. The decadal oscillations of daily extreme rainfall in different seasons are determined using the quantile perturbation method and then tested for the presence of nonstationarity. The attribution analysis of significant extreme rainfall events based on the Monte Carlo method is performed by comparing the occurrence probability under natural forcing alone and under natural plus anthropogenic forcings. The results reveal a climate change footprint in the decadal oscillations of extreme rainfall, with significant upward trends ranging between 27% and 56% of the continental area in different seasons. From a spatial point of view, western Europe characterized by strong upward trends is the most hazardous region of the continent to extreme rainfall events. We also find that the extreme rainfall events under climate change have become twice as frequent as under natural forcing. The attribution of human-caused climate change to significant extreme rainfall events over Europe varies with seasons and is in the range of 35-52%. [ABSTRACT FROM AUTHOR]

Background: Vaccination has played a pivotal role in reducing the burden of COVID-19. Despite numerous studies highlighting its benefits in reducing the risk of severe disease and death, we still lack a quantitative understanding of how varying vaccination roll-out rates influence COVID-19 mortality. Methods: We developed a framework for estimating the number of avertable COVID-19 deaths (ACDs) by vaccination in Iran. To achieve this, we compared Iran's vaccination roll-out rates with those of eight model countries that predominantly used inactivated virus vaccines. We calculated net differences in the number of fully vaccinated individuals under counterfactual scenarios where Iran's per-capita roll-out rate was replaced with that of the model countries. This, in turn, enabled us to determine age specific ACDs for the Iranian population under counterfactual scenarios where number of COVID-19 deaths are estimated using all-cause mortality data. These estimates covered the period from the start of 2020 to 20 April 2022. Results: We found that while Iran would have had an approximately similar number of fully vaccinated individuals under counterfactual roll-out rates based on Bangladesh, Nepal, Sri Lanka, and Turkey (~ 65–70%), adopting Turkey's roll-out rates could have averted 50,000 (95% confidence interval: 38,100–53,500) additional deaths, while following Bangladesh's rates may have resulted in 52,800 (17,400–189,500) more fatalities in Iran. Surprisingly, mimicking Argentina's slower roll-out led to only 12,600 (10,400–13,300) fewer deaths, despite a higher counterfactual percentage of fully vaccinated individuals (~ 79%). Emulating Montenegro or Bolivia, with faster per capita roll-out rates and approximately 50% counterfactual full vaccination, could have prevented more deaths in older age groups, especially during the early waves. Finally, replicating Bahrain's model as an upper-bound benchmark, Iran could have averted 75,300 (56,000–83,000) deaths, primarily in the > 50 age groups. Conclusions: Our analysis revealed that faster roll-outs were consistently associated with higher numbers of averted deaths, even in scenarios with lower overall coverage. This study offers valuable insights into future decision-making regarding infectious disease epidemic management through vaccination strategies. It accomplishes this by comparing various countries' relative performance in terms of timing, pace, and vaccination coverage, ultimately contributing to the prevention of COVID-19-related deaths. [ABSTRACT FROM AUTHOR]

Urbanisation and climate change are augmenting the uncertainty surrounding the future state of the world’s water resource and are resulting in cities experiencing growing levels of risk of pluvial flooding. Drainage infrastructure is generally built using the paradigm of ‘predict and optimise’; however, this approach fails to account for erroneous predictions. This can result in drainage systems delivering insufficient levels of flood protection. Irrespective of these uncertainties new drainage systems must be built, and existing ones adapted in such a way that they remain reliable. This work presents a critical analysis of the drivers of change of urban pluvial flooding and the uncertainties surrounding urban flood planning; thereby highlighting the shortcomings of current planning methodologies. Different Decision Making Under Deep Uncertainty (DMDU) frameworks are then explored and it is shown that they offer an improved ability to design reliable urban flood systems regardless of highly uncertain future conditions. [ABSTRACT FROM AUTHOR]

Inefficient collection and scheduling procedures negatively affect residential curbside collection (RCC) efficiency, greenhouse gas (GHG) emissions, and cost. As Florida aims to achieve a 75% recycling goal by 2020, municipalities have switched to single-stream recycling to improve recycling efficiency. Waste diversion and increased collection cost have forced some municipalities to reduce garbage collection frequency. The goal of this study was to explore the trade-offs between environmental and economic factors of RCC systems in Florida by evaluating the RCC system design of 25 different Central Florida communities. These communities were grouped into four sets based on their RCC garbage, yard waste, and recyclables collection design, i.e., frequency of collection and use of dual-stream (DS) or single-stream (SS) recyclables collection system. For the 25 communities studied, it was observed that RCC programs that used SS recyclables collection system recycled approximately 15–35%, by weight of the waste steam, compared to 5–20% for programs that used DS. The GHG emissions associated with collection programs were estimated to be between 36 and 51 kg CO 2eq per metric ton of total household waste (garbage and recyclables), depending on the garbage collection frequency, recyclables collection system (DS or SS), and recyclables compaction. When recyclables offsets were considered, the GHG emissions associated with programs using SS were estimated between −760 and −560, compared to between −270 and −210 kg CO 2eq per metric ton of total waste for DS programs. These data suggest that RCC system design can significantly impact recyclables generation rate and efficiency, and consequently determine environmental and economic impacts of collection systems. Recycling participation rate was found to have a significant impact on the environmental and financial performance of RCC programs. Collection emissions were insignificant compared to the benefits of recycling. SS collection of recyclables provided cost benefits compared to DS, mainly due to faster collection time. [ABSTRACT FROM AUTHOR]

Early identification and detection of abnormal patterns is vital for a number of applications. In manufacturing for example, slide shifts and alterations of patterns might be indicative of some production process anomaly, such as machinery malfunction. Usually due to the continuous flow of data, monitoring of manufacturing processes and other types of applications requires automated control chart pattern recognition (CCPR) algorithms. Most of the CCPR literature consists of supervised classification algorithms. Fewer studies consider unsupervised versions of the problem. Despite the profound advantage of unsupervised methodology for less manual data labeling their use is limited due to the fact that their performance is not robust enough and might vary significantly from one algorithm to another. In this paper, we propose the use of a consensus clustering framework that takes care of this shortcoming and produces results that are robust with respect to the chosen pool of algorithms. Computational results show that the proposed method achieves not less than 79.10% G -mean with most of test instances achieving higher than 90%. This happens even when in the algorithmic pool are included algorithms with performance less than 15%. To our knowledge, this is the first paper proposing an unsupervised consensus learning approach in CCPR. The proposed approach is promising and provides a new research direction in unsupervised CCPR literature. [ABSTRACT FROM AUTHOR]

Given the important role of hydropower in peak electricity management, Middle Eastern countries are actively pursuing development of more hydropower resources by construction of large dams. Nonetheless, climate change is expected to affect the future productivity of hydropower by influencing the hydrologic cycle and different climate variables in the region. Although reactive plans to minimize climate change impacts on hydropower production have been implemented in the developed world, the developing world can still benefit from proactive actions. Studies of climate change impacts before and during implementation of hydropower projects can result in timely responses and adaptation to climate change with a potential of considerable cost savings. This study investigates the potential impacts of climate change on the hydropower systems in the Karkheh River Basin-the third largest river basin in Iran-in terms of potential for hydroelectricity generation. A simulation model is developed to examine how hydropower generation levels vary for different future climate change scenarios in this representative Middle Eastern basin. The obtained results suggest that the existing operation rules and design specifications, developed based on the historical climatic conditions, can lead to inefficient operations of the hydropower in the basin. Because of insignificant streamflow reductions in the short term, hydropower production may not change considerably in the near future. However, a serious hydropower generation deficit is expected in the midterm and long-term horizons in the Karkheh River Basin. Therefore, adaptation to the future climate change conditions and revision of the operation rule curves and design specifications are essential to optimal hydropower operations in this basin. [ABSTRACT FROM AUTHOR]

The imbalance between energy resource availability, demand, and production capacity, coupled with inherent economic and environmental uncertainties make strategic energy resources planning, management, and decision-making a challenging process. In this paper, a descriptive approach has been taken to synthesize the world's energy portfolio and the global energy balance outlook in order to provide insights into the role of Organization of Petroleum Exporting Countries (OPEC) in maintaining "stability" and "balance" of the world's energy market. This synthesis illustrates that in the absence of stringent policies, i.e., if historical trends of the global energy production and consumption hold into the future, it is unlikely that non-conventional liquid fuels and renewable energy sources will play a dominant role in meeting global energy demand by 2030. This should be a source of major global concern as the world may be unprepared for an ultimate shift to other energy sources when the imminent peak oil production is reached. OPEC's potential to impact the supply and price of oil could enable this organization to act as a facilitator or a barrier for energy transition policies, and to play a key role in the global energy security through cooperative or non-cooperative strategies. It is argued that, as the global energy portfolio becomes more balanced in the long run, OPEC may change its typical high oil price strategies to drive the market prices to lower equilibria, making alternative energy sources less competitive. Alternatively, OPEC can contribute to a cooperative portfolio management approach to help mitigate the gradually emerging energy crisis and global warming, facilitating a less turbulent energy transition path while there is time. [ABSTRACT FROM AUTHOR]

• A generic framework to generate continuous, high-resolution groundwater level data. • The framework helps fill missing observations at monitored and non-monitored sites. • Application of the framework in agro-urban regions of the Indus Basin is presented. • Major urban areas in the Indus Basin experience significant GWL drop (0.9 m/year) • Groundwater level data capture changes between upstream–downstream croplands. High-resolution, continuous groundwater data is important for place-based adaptive aquifer management. This information is unavailable in many areas due to spatial sparsity of and temporal gaps in groundwater monitoring. This study advances the ability to generate high-resolution (1 km2), temporally continuous estimates of groundwater level (GWL) changes by incorporating 1 km2 covariates and existing piezometer observations into predictive modeling. We employed a hybrid machine learning (ML) model, primarily using the geographically weighted random forest (RF gw) model. To assess the performance of the RF gw model, we conducted a comprehensive comparison with the SGS geostatistical method and non-spatial ML models (RF and XGBoost). The framework was implemented across the Indus Basin using biannual (July and Oct) GWL data from piezometers and local covariates from 2003 to 2020. The RF gw model demonstrated superior accuracy in predicting GWLs, improving R2 by 10 %, 17 %, and 22 % compared to SGS, RF, and XGBoost, respectively. Notably, SGS, RF, and XGBoost substantially underestimated the GWL in deeper wells (7–11 m), whereas RF gw showed a much smaller underestimation (up to ∼ 3 m). The 90 % prediction interval revealed that RF gw had less uncertainty (1–3 m) followed by RF (2–5 m), and SGS and XGBoost (up to 8 m) for most testing piezometers. Incorporating high-resolution covariates into RF gw predictive modeling provided reliable estimates of GWL changes for unmonitored sites. Using the reconstructed GWL data, we examined the GWL changes in head (i.e., upstream) and tail (i.e., downstream) farms within canal distributaries, illustrating faster groundwater drawdown in tail farms (e.g., 0.82 m/yr) than head farms (0.02 m/yr in the Hakra canal distributary). Densely populated urban areas (e.g., Lahore, Multan, and Faisalabad) had the highest GWL decline (e.g., up to 0.9 m/yr). The framework can be used in other groundwater-stressed regions to support better aquifer management in the face of limited in-situ observations. [ABSTRACT FROM AUTHOR]

We convened a workshop to enable scientists who study water systems from both social science and physical science perspectives to develop a shared language. This shared language is necessary to bridge a divide between these disciplines' different conceptual frameworks. As a result of this workshop, we argue that we should view socio-hydrological systems as structurally coconstituted of social, engineered, and natural elements and study the "characteristic management challenges" that emerge from this structure and reoccur across time, space, and socioeconomic contexts. This approach is in contrast to theories that view these systems as separately conceptualized natural and social domains connected by bi-directional feedbacks, as is prevalent in much of the water systems research arising from the physical sciences. A focus on emergent characteristic management challenges encourages us to go beyond searching for evidence of feedbacks and instead ask questions such as: What types of innovations have successfully been used to address these challenges? What structural components of the system affect its resilience to hydrological events and through what mechanisms? Are there differences between successful and unsuccessful strategies to solve one of the characteristic management challenges? If so, how are these differences affected by institutional structure and ecological and economic contexts? To answer these questions, social processes must now take center stage in the study and practice of water management. We also argue that water systems are an important class of coupled systems with relevance for sustainability science because they are particularly amenable to the kinds of systematic comparisons that allow knowledge to accumulate. Indeed, the characteristic management challenges we identify are few in number and recur over most of human history and in most geographical locations. This recurrence should allow us to accumulate knowledge to answer the above questions by studying the long historical record of institutional innovations to manage water systems. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hydropolitical conflicts between the Eastern Nile countries over the Grand Ethiopian Renaissance Dam (GERD) are systematically analyzed at three points in time: just before the announcement of construction by Ethiopia on April 11, 2011, before the negotiations in early January 2014, and late August 2014. Hypergame theory, as developed within the framework of the Graph Model for Conflict Resolution for handling misperceptions, is used to gain strategic insights into these conflicts and to ascertain the possible resolutions of the disputes. In all of three conflicts, the key decision makers are Egypt and Sudan, the downstream countries, and Ethiopia, the upstream nation. The findings from the analyses demonstrate the significant utilization of strategic surprise, a decisive act in which a decision maker intentionally exercises a course of action in the dispute that is hidden to its opponents in order to attempt to reach a more desirable outcome for itself. In particular, both Egypt and Sudan were caught by surprise when Ethiopia publicly announced on April 11, 2011 that it was going to build GERD, since no prior notification was given. Because Ethiopia was aware of Egypt and Sudan's misperception this dispute is modeled as a second level hypergame. The conflict investigations also show that the geopolitical and economic changes in Egypt, Sudan, and Ethiopia allowed Ethiopia to construct the dam without any harsh confrontation with Egypt and Sudan. [ABSTRACT FROM AUTHOR]

By combining long-term ground-based data on water withdrawal with climate model projections, this study quantifies the compounding effects of human activities and climate change on surface water availability in Iran over the twenty-first century. Our findings show that increasing water withdrawal in Iran, due to population growth and increased agricultural activities, has been the main source of historical water stress. Increased levels of water stress across Iran are expected to continue or even worsen over the next decades due to projected variability and change in precipitation combined with heightened water withdrawals due to increasing population and socio-economic activities. The greatest rate of decreased water storage is expected in the Urmia Basin, northwest of Iran, (varying from ~ − 8.3 mm/year in 2010–2039 to ~ − 61.6 mm/year in 2070–2099 compared with an observed rate of 4 mm/year in 1976–2005). Human activities, however, strongly dominate the effects of precipitation variability and change. Major shifts toward sustainable land and water management are needed to reduce the impacts of water scarcity in the future, particularly in Iran's heavily stressed basins like Urmia Basin, which feeds the shrinking Lake Urmia. [ABSTRACT FROM AUTHOR]

Highlights • Joint analysis of human-landscape and climate drivers of lake shrinkage was performed. • Climate change is not the main cause of water level decline in Lake Urmia. • Agricultural vegetation expansion since 2000 has increased upstream water consumption. • Increased water consumption is the likely driver of Lake Urmia desiccation. Abstract Lake Urmia—a shallow endemic hypersaline lake in northwest Iran—has undergone a dramatic decline in its water level (WL), by about 8 m, since 1995. The primary cause of the WL decline in Lake Urmia has been debated in the scientific literature, regarding whether it has been predominantly driven by atmospheric climate change or by human activities in the watershed landscape. Using available climate, hydrological, and vegetation data for the period 1981–2015, this study analyzes and aims to explain the lake desiccation based on other observed hydro-climatic and vegetation changes in the Lake Urmia watershed and classical exploratory statistical methods. The analysis accounts for the relationships between atmospheric climate change (precipitation P, temperature T), and hydrological (soil moisture SM, and WL) and vegetation cover (VC; including agricultural crops and other vegetation) changes in the landscape. Results show that P, T, and SM changes cannot explain the sharp decline in lake WL since 2000. Instead, the agricultural increase of VC in the watershed correlates well with the lake WL change, indicating this human-driven VC and associated irrigation expansion as the dominant human driver of the Lake Urmia desiccation. Specifically, the greater transpiration from the expanded and increasingly irrigated agricultural crops implies increased total evapotranspiration and associated consumptive use of water (inherently related to the irrigation and water diversion and storage developments in the watershed). Thereby the runoff from the watershed into the lake has decreased, and the remaining smaller inflow to the lake has been insufficient for keeping up the previous lake WL, causing the observed WL drop to current conditions. [ABSTRACT FROM AUTHOR]

Reforms currently under way in China's electricity markets bear important implications for its decarbonization objectives. The southwestern province of Yunnan is among the provinces piloting the current iteration of power market reforms. As such, lessons from Yunnan will inform future market reform and renewable energy policies in China and potentially elsewhere. The dominance of hydropower in Yunnan's energy portfolio and the particular transmission constraints it faces, offer an interesting case study of the challenges of decarbonization. We report on market architecture reforms and aggregate market data collected from the Yunnan Power Exchange. We review four elements in the reformed market architecture. Market pricing rules, transitional quantity controls, the generation rights market, and inter-provincial trade. The specifics of market reform reflect a compromise between decarbonization, inter-provincial competition, grid security and development objectives and contribute to understanding of how the dual transitions of hydropower decarbonization and market liberalization interact. We conclude on six insights regarding the role of the grid operator, security checks on trade, integration of cascade hydropower, the inclusion of renewables in the generation rights market, price controls, and market participant price uncertainty. [ABSTRACT FROM AUTHOR]

The uncertainty of a changing climate raises challenges for water infrastructure planning and design. Not accounting for nonstationarity may result in under-designed structures that fail too frequently, or over-designed structures that are economically inefficient. This concern is magnified by uncertainty in the long-term frequency and magnitude of future extreme events. Planning strategies that allow adaptations over a structure's life could improve both reliability and economic efficiency. This study develops a method to inform adaptive water infrastructure planning with uncertain hydrologic and other forms of nonstationarity, applied to levee system planning. A stochastic dynamic programming model including a Markov process is developed for infrastructure planning with uncertain nonstationarity in flood frequency. Bayes' theorem is used to update peak flow probabilities conditioned on observed past peak flows and to update expected residual flood damages over time. A levee system planning problem with a numerical example from California illustrates the approach to derive optimal levee heights over time, and economic values of adapting to uncertain nonstationary flood risk. The projected range of probabilistic hydrology scenarios affects the optimal results, particularly in later planning stages as hydrology scenarios diverge with time. Adaptive planning strategies allowing more levee upgrades over time slightly lowers the overall cost and provides better flood protection than one-time construction under nonstationary hydrology for any climate in the example. Compared to a known future nonstationary hydrology, incorporating uncertain nonstationary climate results in higher levees being planned for observed severe hydrology scenarios in later stages. The overall present value cost with uncertain nonstationary climate depends on rates of change in peak flow distribution parameters in future hydrology scenarios. [ABSTRACT FROM AUTHOR]

Lake Urmia in northwest Iran, once one of the largest hypersaline lakes in the world, has shrunk by almost 90% in area and 80% in volume during the last four decades. To improve the understanding of regional differences in water availability throughout the region and to refine the existing information on precipitation variability, this study investigated the spatial pattern of precipitation for the Lake Urmia basin. Daily rainfall time series from 122 precipitation stations with different record lengths were used to extract 15 statistical descriptors comprising 25th percentile, 75th percentile, and coefficient of variation for annual and seasonal total precipitation. Principal component analysis in association with cluster analysis identified three main homogeneous precipitation groups in the lake basin. The first sub-region (group 1) includes stations located in the center and southeast; the second sub-region (group 2) covers mostly northern and northeastern part of the basin, and the third sub-region (group 3) covers the western and southern edges of the basin. Results of principal component (PC) and clustering analyses showed that seasonal precipitation variation is the most important feature controlling the spatial pattern of precipitation in the lake basin. The 25th and 75th percentiles of winter and autumn are the most important variables controlling the spatial pattern of the first rotated principal component explaining about 32% of the total variance. Summer and spring precipitation variations are the most important variables in the second and third rotated principal components, respectively. Seasonal variation in precipitation amount and seasonality are explained by topography and influenced by the lake and westerly winds that are related to the strength of the North Atlantic Oscillation. Despite using incomplete time series with different lengths, the identified sub-regions are physically meaningful. [ABSTRACT FROM AUTHOR]

The article discusses the challenges and opportunities associated with the large-scale hydropower system development in China. Topics covered include insights on topical areas of hydropower generation, transmission, and absorption, areas where the history of water resources systems research and modeling approaches can help address these challenges, and the need to model complex hydraulic and electrical relations in large-scale cascade hydropower systems.

The soon-to-be completed Grand Ethiopian Renaissance Dam (GERD), which will be the largest hydroelectric power plant and among the largest reservoirs in Africa, has highlighted the need for expanding traditional integrated water resources management to better include the cultural, social, and political complexities of large water infrastructure in development projects. The GERD will store a maximum of 74 billion cubic meters of water corresponding to approximately the average annual outflow of the Nile from the Aswan high dam. Undoubtedly, the GERD will be vital for energy production and a key factor for food production, economic development, and poverty reduction in Ethiopia and the Nile Basin. However, the GERD is also a political statement that in one stroke has re-written the hydropolitical map of the Nile Basin. The GERD has become a symbol of Ethiopian nationalism or 'renaissance' (hidase in Amharic). A contrasting concept to nationalism is hydrosolidarity. This concept has been put forward to better stress equitable use of water in international water management challenges that would lead to sustainable socioeconomic development. We use the opposing notions of nationalism and hydrosolidarity at three different scales, everyday politics, state policies, and interstate and global politics to analyse some aspects of the new hydropolitical map of the Nile Basin. We argue that nationalism and national interests are not necessarily negative standpoints but that there may instead be a meeting point where regional and national interests join with hydrosolidarity principles. We believe that this meeting point can maximize not only the common good, but also the good from a national interest point of view. For this, it is important not increase collaboration instead of being locked in to the historical narrative of nationalistic culture and historical discourse. This would benefit and improve future sustainability. [ABSTRACT FROM AUTHOR]

Highlights: [•] Assessment of water transfer as a solution to water shortages in central Iran. [•] Developing a system dynamics model for the Zayandeh-Rud River Basin. [•] Understanding the casual relationship between different components of the problem. [•] Identifying the main driver of water shortages in the basin. [•] Providing policy insights based on the Fixes that Backfire system archetype. [Copyright &y& Elsevier]

Abstract: Increasing private sector involvement in transportation services has significant implications for the management of road networks. This paper examines a concession model’s effects on a road network in the mid-sized city of Fresno, California. Using the existing transportation planning models of Fresno, we examine the effects of privatization on a number of typical system performance measures including total travel time and vehicle miles traveled (VMT), the possibility of including arterials, and the differences between social cost prices and profit maximizing prices. Some interesting insights emerge from our analysis: (1) roads cannot be considered as isolated elements in a concession model for a road network; (2) roads can function as complements at some levels of demand and become substitutes at other levels; (3) policy makers/officials should consider privatizing/pricing arterials along with privatizing highways; (4) temporally flexible but limited price schedule regulations should be part of leasing agreements; and (5) non-restricted pricing may actually worsen system performance, while limited pricing can raise enormous profits as well as improve system performance. [Copyright &y& Elsevier]

Abstract: This study evaluates climate change impacts on crop production and water productivity of four major crops (wheat, barley, rice, and corn) in Iran''s Zayandeh-Rud River Basin. Multi-model ensemble scenarios are used to deal with uncertainties in climate change projections for the study period (2015–2044). On average, monthly temperature will increase by 1.1 to 1.5°C under climate change. Monthly precipitation changes may be positive or negative in different months of the year. Nevertheless, on the annual basis, precipitation will decrease by 11 to 31% with climate change. While warming can potentially shorten the crop growth period, crop production and water productivity of all crops are expected to decrease due to lower precipitation and higher water requirements under higher temperature. Out of the four studied crops, rice and corn are more vulnerable to climate change due to their high irrigation water demand. So, their continued production can be compromised under climate change. This finding is of particular importance, given the locally high economic and food value of these crops in central Iran. [Copyright &y& Elsevier]

This paper explores the independent and combined effects of changes in temperature and runoff volume on California's water supply and potential water management adaptations. Least-cost water supply system adaptation is explored for two climate scenarios: 1) warmer-drier conditions, and 2) warmer conditions without change in total runoff, using the CALVIN economic-engineering optimization model of California's intertied water supply system for 2050 water demands. The warm-dry hydrology was developed from downscaled effects of the GFDL CM2.1 (A2 emissions scenario) global climate model for a 30-year period centered at 2085. The warm-only scenario was developed from the warm-dry hydrology, preserving its seasonal runoff shift while maintaining mean annual flows from the historical hydrology. This separates the runoff volume and temperature effects of climate change on water availability and management adaptations. A warmer climate alone reduces water deliveries and increases costs, but much less than a warmer-drier climate, if the water supply system is well managed. Climate changes result in major changes in reservoir operations, cyclic storage of groundwater, and hydropower operations. [ABSTRACT FROM AUTHOR]