Search

Over the past year, procurement in the public sector has attracted increased attention as governments have fought COVID-19 - first by trying to provide the vast array of equipment needed by the medical system and then by buying and distributing vaccines. At the same time, large government projects in Canada continue, ranging from Site C hydroelectric project in British Columbia to new fight jets and Navy ships for the Canadian Forces. These examples illustrate the overall relevance of public procurement. In this special issue, we have brought together a number of articles that address important aspects of public procurement in Canada.

Transient stability of a multi‐unit hydroelectric generating system significantly influences the safety operation of power stations. The uncertainty of operating parameter is one of the important factors to influence the system stability during the transient process. For this reason, the target of this paper aims to explore the optimised operating parameter in order to enhance the stability of a multi‐unit hydroelectric generating system. To overcome the limitations of existing methods in literature, a new high‐dimensional, complex and non‐linear dynamic model of the multi‐unit hydroelectric generating system that combines the conventional hydro‐turbine governing system and the shaft system is established. Then, the dynamic behaviour of the proposed system targeting the transient process is exhaustingly investigated with the change of the critical parameters. The calm interval of critical parameters is also determined in order to improve the transient stability of the system. The obtained results not only enrich the theoretical knowledge of transient dynamics but also ensure the safety operation of hydropower stations. Meanwhile, the presented research method, high‐dimensional non‐linear dynamic model and the interesting findings in transient process can promote the development of the theory of non‐linear dynamics.

Small hydroelectric power (SHP) facilities are proliferating around the world, including in Brazil where legislation encourages SHP over other hydropower development, defining SHP as facilities with installed capacities of 3–30 MW and reservoirs

Accurate data characterizing species distribution and abundance are critical for conservation and management of aquatic resources. Inventory methods, such as gillnet surveys, are widely used to estimate distribution and abundance of fish. However, gillnet surveys can be costly in terms of material and human resources, may cause unwanted mortality in the fish communities being studied, and is subject to size and species selection bias. Detecting allochthonous DNA released by species in their environment (i.e., environmental DNA, hereafter eDNA) could be used as a noninvasive and less costly alternative. In this study, we directly compare eDNA metabarcoding and gillnets for monitoring freshwater fish communities in terms of species richness and relative species abundance. Metabarcoding was performed with the 12S Mifish primers. We also used species‐specific quantitative PCR (qPCR) for the most abundant species, the walleye (Sander vitreus), to compare estimated relative abundance with metabarcoding and gillnet captures. Water sample collection, prior to gillnet assessment, was performed on 17 sites in the hydroelectric impoundment of the Rupert River (James Bay, Canada), comparing two water filtration methods. After controlling for amplification biases and repeatability, we show that fish communities’ complexity is better represented using eDNA metabarcoding than previously recorded gillnet data and that metabarcoding read count correlates with qPCR (r = 0.78, p

Altered rivers and managed flows are a hallmark of civilization and dams are a principal agent of alteration. Peak dam construction occurred at the turn of the last century in Western countries, and many of the largest dams are reaching the end of their service life. As a result, dam operators are increasingly facing a complex renewal/removal decision‐making process in a large part because the economic and social values of dams have changed. The Mactaquac Hydroelectric Generating Station (New Brunswick, Canada), operated by NB Power Corporation (NB Power), is Canada's 25th largest dam and it is reaching the end of its service life. A decision is required for the dam's future state and three options were originally proposed: renew, rebuild, or remove. An overarching science framework was developed with NB Power to inform and support decision‐making for the dam's decision process and an impending Environmental Impact Assessment. The framework guides research and monitoring for dam renewal/removal using science‐based solutions that aim to minimize impacts on the aquatic environment while supporting an efficient and cost‐effective decision‐making process. The framework has five components: (a) establish long‐term baselines of environmental conditions; (b) develop normal ranges describing the river's natural variability; (c) integrated physical and biological modelling; (d) assess the specific and cumulative state of fish passage; and (e) create and sustain a user‐friendly geospatial data management system. In this paper we present a case study that implements the science framework (Part 1) through the Mactaquac Aquatic Ecosystem Study (MAES) with a view to revisit and assess its final impact post‐project completion (Part 2).

In this paper, the life span of hydro and nuclear energy generations and the relationship between hydro and nuclear energy generations, environmental pollution, and economic growth were investigated for Japan covering the period of 1960–2018 by employing the Bathtub‐Weibull curve and Markov switching‐vector error correcting (MSVEC) method, respectively. According to the Bathtub‐Weibull curve analysis, a rising failure rate for nuclear energy was found, indicating that the life of nuclear energy has expired, but a decreasing failure rate for hydroelectric energy has been detected. Then two different MSVEC models were used. The MSVEC method, unlike traditional approaches, determines the relationship between variables under different regimes. The results of MSVEC methods indicate three important points. First, regime‐dependent asymmetry and regime changes are crucial for policy recommendations. Second, the shocks to hydropower and nuclear energy generations cause temporary deviations from the long‐run growth path in both regimes. Lastly, the increase in hydropower generation leads to a decrease in environmental pollution and an increase in GDP, and an increase in nuclear power generation increases pollution and growth in both regimes.

Quantifying the downstream survival of migrating fish past dams is critical for conservation efforts. Regulators require assessments of survival as a condition of operation. Failure to meet an established survival standard may result in required operational or costly structural changes at a facility. Establishing the survival standard, as well as the rules of assessment, is a point of contention between regulators and operators. Management goals are based on biological criteria, but there are inherent statistical and probabilistic trade‐offs when choosing a standard value and the method for assessment. We make a distinction between a “biological” goal (the conservation goal) and a “statistical” standard (a function of the biological goal, sample size, assessment method, and years of consecutive evaluation). An effective statistical standard maximizes true positives (passing the standard when the biological goal is being met) and true negatives (failing the standard when the goal is not being met), while minimizing false negatives and false positives. We explored the effects of sample size, true survival, and assessment methods on the probability of passing different statistical standards by simulating survival studies (simulating mark‐recapture experiments). We observed a strong influence of assessment methods on the probability of making the right decision (true positive or true negative), especially when sample size, and recapture probability was low. As a support tool, we developed an interactive user interface to explore specific scenarios, and to aid communication among decision‐makers.

Globally, policies aiming for conservation of species, free-flowing rivers, and promotion of hydroelectricity as renewable energy and as a means to decarbonize energy systems generate trade-offs between protecting freshwater fauna and development of hydropower. Hydroelectric turbines put fish at risk of severe injury during passage. Therefore, comprehensive, reliable analyses of turbine-induced fish mortality are pivotal to support an informed debate on the sustainability of hydropower (i.e., how much a society is willing to pay in terms of costs incurred on rivers and their biota). We compiled and examined a comprehensive, global data set of turbine fish-mortality assessments involving275,000 individual fish of 75 species to estimate mortality across turbine types and fish species. Average fish mortality from hydroelectric turbines was 22.3% (95% CI 17.5-26.7%) when accounting for common uncertainties related to empirical estimates (e.g., handling- or catch-related effects). Mortality estimates were highly variable among and within different turbine types, study methods, and taxa. Technical configurations of hydroelectric turbines that successfully reduce fish mortality and fish-protective hydropower operation as a global standard could balance the need for renewable energy with protection of fish biodiversity.Mortalidad evidente, pero dependiente del contexto, de peces que pasan por turbinas hidroeléctricas Resumen Globalmente, las políticas que buscan la conservación de especies, el flujo libre de ríos y la promoción de la hidroeléctrica como una energía renovable y como un medio para reducir el carbono en sistemas de energía generan pros y contras entre la protección de la fauna de agua dulce y el desarrollo de la hidroeléctrica. Las turbinas hidroeléctricas ponen a los peces en riesgo de heridas severas al pasar por ellas. Por lo tanto, análisis integrales, confiables de la mortalidad de peces inducida por turbinas son esenciales para sustentar un debate informado de la sustentabilidad de la energía hidroeléctrica (i. e., que tan dispuesta esta una sociedad para pagar en términos de costos incurridos en los ríos y su biota). Compilamos y examinamos un conjunto de datos integrales, globales de evaluaciones de mortalidad de peces en turbinas involucrando275,000 peces individuales de 75 especies para estimar la mortalidad en tipos de turbinas y especies de peces. La mortalidad promedio de peces en turbinas hidroeléctricas fue 22.3% (95% IC 17.5-26.7%) cuando se consideraron incertidumbres comunes relacionadas con las estimaciones empíricas (e. g., efectos relacionados con el manejo o captura). Las estimaciones de mortalidad fueron muy variables entre y dentro de los diferentes tipos de turbinas, métodos de estudio y taxones. Las configuraciones técnicas de las turbinas hidroeléctricas que exitosamente reduzcan la mortalidad de peces y proporcionen una operación protectora de peces como un estándar global podrían equilibrar la necesidad de energía renovable con la protección de la biodiversidad de peces.【摘要】在全球范围内, 旨在保护物种、促进河流自由流动, 以及促进水电作为可再生能源及作为能源系统碳减排方法的政策在保护淡水动物和开发水电之间存在着利弊权衡。鱼类在通过水电涡轮机时面临受到严重伤害的风险。因此, 对水电涡轮机引起的鱼类死亡情况进行全面、可靠的分析, 对于支持关于水电可持续性的基于知识的辩论(即社会愿意为河流及其生物群落付出多少成本)至关重要。我们整理并分析了一个全面的全球涡轮机导致鱼类死亡的评估数据集, 涉及75种鱼类超过275,000条个体, o以估计不同类型的涡轮机引起的不同鱼类物种的死亡率。我们将经验估计中常见的不确定性(如处理或捕鱼相关的影响)纳入考虑, 发现水电涡轮机导致的鱼类平均死亡率为22.3%(95%CI为17.5-26.7)。不同涡轮机类型、研究方法, 以及鱼类类群组内和组间的鱼类死亡率估计值都有很大差异。我们建议将成功降低鱼类死亡率并能为鱼类提供保护的水电装置作为全球水电涡轮机的标准技术配置, 以平衡对可再生能源的需求与对鱼类生物多样性的保护。【翻译: 胡怡思;审校:聂永刚】.

In this study, the effect of the COVID‐19 pandemic on electrical energy storage technologies was investigated. The results of the crises and opportunities created by this unpredictable epidemic in the future processes were evaluated according to energy and especially electrical energy storage areas. Home quarantines used to reduce the spread of the epidemic significantly increased the electrical energy needs of home users. In addition, great changes have occurred in public transportation habits during the COVID‐19 pandemic, and it has been observed that approximately 20% of individuals may prefer electric micromobility devices working with lithium batteries due to the risk of infection in closed areas such as public buses or metros. Although the demand for main energy sources has decreased significantly during the COVID‐19 pandemic, it is important that the percentage of energy produced from renewable energy sources increases by about 1%. With the increasing use of renewable energy sources and the increasing importance of the concept of sustainability in all areas of our lives, energy storage systems compatible with renewable energy technologies will become more and more important. At the beginning of these technologies, hydroelectric energy storage systems with closed‐loop pumps are preferred for large‐scale applications. [ FROM AUTHOR] Copyright of Energy Storage (2578-4862) is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all Abstracts.)

There are 104 hydroelectric facilities proposed to be installed in the watersheds that feed the Pantanal, a vast floodplain wetland located mostly in Brazil. The Pantanal is host to 23 long‐distance migratory fish species that ascend upland tributaries to spawn. A Geographic Information System was used to predict the impact of hydroelectric dams on potential migration routes for these species. Both anthropogenic (hydroelectric dams) and natural barriers were included in the analysis. Natural barriers were identified by river slope. Critical river slopes of 10 and 25%, above which fish were predicted to be incapable of ascending, were modeled as natural barriers. Based on this model, we show that between 2 and 14% of rivers in the Pantanal watershed are naturally blocked to fish migration. An additional 5 to 9% of rivers are currently blocked due to 35 existing hydroelectric facilities. If all proposed dams are built, the area flooded by new reservoirs will triple and the river kilometers blocked will double, blocking 25 to 32% of the river system to fish migration. The Taquari and Cuiaba River sub‐basins will be the most impacted, each having more than 70% of their rivers blocked. The impact of individual proposed facilities on the loss of migration routes is related to their proximity to existing barriers. Fourteen of the proposed dams are upstream from existing barriers and will therefore not further restrict long‐distance fish migration routes while proposed dams are predicted to close an additional 11,000 to 12,000 km of river channels.

Despite the recent discoveries of considerable fossil fuel reserves, Brazil is one of the only great economic and industrial powers with very high amounts of renewable energy in its electricity matrix. Approximately 79.3% of the electric energy supply comes from renewable resources, of which hydroelectric power represents 70.6%. The two primary concerns regarding hydroelectricity are the damage caused to the environment by the construction of dams and the uncertainty of the supply in cases of long drought seasons. This article presents an analysis on the availability and energy exploitation of sugarcane straw and forest residues derived from eucalyptus for decentralized generation using a Geographic Information System–based model. The potential bioelectricity and bioethanol production from sugarcane and eucalyptus biomass in the Administrative Region of Campinas (ARC) is higher than the demand in this region. The results provide guidelines for designing alternatives to the intended Nationally Determined Contributions in Brazil within the scope of the ARC, and they can be used to provide energy empowerment, electric matrix diversification, and new policies that address the residue availability and demand., Assessment of agriculture biomass residues to replace fossil fuels and hydroelectric power energy – A spatial approach.

Flow modification of lotic ecosystems is one of the main threats to global freshwater biodiversity. Commonly, and in the river studied here, modification results from hydroelectric dam installation. We evaluated the impacts of damming on zooplankton communities in the Amazonian floodplain of the Madeira River (Porto Velho, Rondonia, Brazil) following construction in 2012 of the run‐of‐river dam of Jirau Hydroelectric Power Plant. Using data sampled between 2009 and 2015, we tested for discontinuities in zooplankton community composition attributable to damming and the naturally occurring flood pulse. The flood pulse remained the main predictor explaining variation in zooplankton community structure even with the installation of the dam on the Madeira River. Despite this, discontinuities for the entire zooplankton community and for the main compositional groups (testate amoebae, rotifers, cladocerans, and copepods) were detected in relation to the dam (pre‐/post‐dam periods), mainly in ebb and low water, and with weaker evidence of dam effects during flood and highwater hydrological periods. A multivariate regression tree explained 9.6% of the variation in zooplankton communities and identified four groups: (1) flood and high‐water periods; (2) low water post‐dam; (3) low water pre‐dam; and (4) ebb hydrological periods. The deviance in each multivariate regression tree node was attributable to variation in eight rotifer, three testate amoeba, and three copepod taxa. Our study demonstrates that the flood pulse, dam construction, and interaction between both of these factors affect zooplankton community structure in the Madeira River. While for many zooplankton community variables, effects occurred mainly during ebb and low‐water periods, some effects were also observed during high water and flood periods. We thus recommend the establishment of a permanent environmental monitoring programme during all hydrological periods in tropical floodplain rivers and the addition of sampling sites downstream from dams. Many rivers in the world are increasingly disrupted by multiple dams, yet little is known of their effects, especially for run‐of‐river dams. Our study identified short‐term impacts of only one run‐of‐river dam on zooplankton communities. More research is needed on the effects of multiple run‐of‐river dams on zooplankton and other biota, especially in tropical floodplain rivers, so that negative effects can be understood and ameliorated.

Motivation In this article, we examine the role of norms in protecting the rights of Indigenous Peoples with regard to hydroelectric dams. We argue that the way large‐scale dams are built and managed—including their impacts on Indigenous Peoples—varies according to the political context of the host country. In more restrictive political contexts, norms may often be neglected or compromised. Purpose The political system and domestic legislation are crucial factors that need to be considered in more depth in research scholarship on dams. We contribute to filling this research gap by presenting a comparative analysis of the Bakun dam in Malaysia and the Gibe III dam in Ethiopia, demonstrating that norms tend to be ignored or compromised in restrictive and authoritarian political environments. Approach and Methods We compare the similarities and differences of these two dam projects systematically drawing on empirical field research comprising interviews, focus group discussions and the analysis of primary and secondary documents. Findings Our research reveals that international and private norms are often neglected in partly free or unfree political systems. Even domestic legislation can be circumvented by a strong or authoritarian state government, and this can lead to serious delays and neglect of protective standards. Policy Implications International standards are often more ambitious than national standards and their implementation in the hydropower dams industry can help to improve the social and environmental sustainability of projects. Active civil society organizations can use norms and standards to strengthen social mobilization within the country and can transmit important information outside the country to build transnational alliances. Pressure and persuasion mechanisms can lead to norm change and norm compliance by state actors.

Ceboruco (2280 m.a.s.l.), in the western Trans-Mexican Volcanic Belt, is considered among the most hazardous volcanoes in Mexico. Some 55,000 people and important infrastructure (e.g. hydroelectric...

Electricity production by hydropower is negatively affected by drought. To understand, monitor and manage risks of less than normal streamflow for hydroelectricity production (HP) at the global sca...

Estimating survival using data on marked individuals is a key component of population dynamics studies resulting management and conservation decisions. When human impacts on populations are considerable, such decisions require not only estimating survival but also quantifying how much mortality is due to anthropogenic versus natural causes. This is of particular importance when individuals vary in their vulnerability to different causes of mortality due to, for example, their body size, developmental stage, or reproductive state. In this study we used multistate mark-recapture models to estimate the effects of individual body size on harvest- and background mortality risks of large freshwater brown trout (Salmo trutta). In doing so, we accounted for additional individual differences in vulnerability to cause-specific mortality by distinguishing individuals passing a hydroelectric dam on their spawning migration from those that reproduced below the dam instead and further investigate temporal patterns of and correlations among mortality hazard rates over 50 years. We found that harvest mortality was highest for intermediate-sized trout, and outweighed background mortality for almost the entire observed size range of trout. For trout spawning above the dam, background mortality decreased for larger body sizes and at lower river discharge. Both mortality causes, as well as the probability of spawning above the dam, varied substantially over time but a trend was evident only for fishers’ reporting rate, which decreased from an average of 80% to only 10% over half a century. Our model demonstrates how continuous size effects can be integrated into analyses of cause-specific mortality by using a novel parameterisation with hazard rates. This allowed us to estimate effects of both size and environment on harvest- and background mortality with-out confounding, and provided an intuitive way to estimate temporal patterns within and correlation among the mortality sources. In combination with compu-tationally fast custom MCMC solutions this modelling framework provides unique opportunities for studying individual heterogeneity in cause-specific mortality using mark-recapture-recovery data.

Longitudinal connectivity is one of the prime issues addressed in river restoration our days. At the same time, mitigation of climate change impacts by modes of renewable energy increasingly puts pressure on the remaining free flowing river stretches for hydroelectricity production. At the site level, this trade‐off manifests in the negotiation of water for upstream and downstream fish passage versus losses for hydroelectricity production. This study has compiled and analysed 193 studies evaluating fish passes designed to provide upstream migration for all species and size classes of the respective river system. The overall assessment of functioning and discharge dedicated to fish pass maintenance, site, and river characters were provided by the studies. The main objective here was deriving general guidance for the minimum amount of water needed for fully functioning upstream fish passage in relation to river size. There was a significant correlation between functionality and design discharge of a fish pass. Fully functioning fish passes (N = 92) had median design discharge of 5% of the mean average discharge of the river, restrictedly functioning of 1.1% and not functioning of 0.22%. A power model could be derived of design discharge needs in relation to river discharge, which is inversely related to river size. In large rivers, a rather small share of mean discharge is sufficient, whereas in small rivers, it cannot be further downscaled due to dimensions. This model might provide first guidance in adjusting needs for both hydroelectricity generation and fish conservation in regulated rivers.

Large-scale hydroelectric dams have—throughout their history—had adverse impacts on local population groups, natural resources, and entire eco-systems furthering resistance and protest against them. In this paper, we aim to investigate the impact of social mobilization against large-scale dams by considering political opportunity structures, actor constellations, and frames. We comparatively analyze three case studies in varying political systems, that is, Gibe III in Ethiopia, Belo Monte in Brazil, and Barro Blanco in Panama. Our investigation is based on field research in these countries comprising data collection of governmental reports, newspaper articles, materials published by civil society organizations, and semi-structured interviews. The analysis reveals that the impact of mobilization against dams is certainly limited in contexts with authoritarian governments. In democratic contexts, the impact depends on the degree of external involvement, as well as the ability of movements to avoid fracture, especially in view of temporal dimensions of large infrastructure projects.

This paper compares the global flows of Chinese overseas investment in power plants with renewable energy investment potential embodied in “Nationally Determined Contributions.” With over US$1tn (671 GW) in Nationally Determined Contributions renewable energy investment potential in developing countries, we estimate the total level of power plant investments from China's policy banks and commercial entities since the early 2000s at US$216bn (158 GW). Although past investment has mainly been directed at fossil fuels and hydroelectric power, we argue that China is uniquely poised to lead renewable energy global investments for three reasons: (i) China's solar and wind industries are globally competitive; (ii) Chinese policy banks can give domestic firms advantages in financing global expansion; and (iii) renewable energy investment opportunities still exist in developing countries with less sovereign risk than for traditional energy investments. The Chinese government should provide special incentives for the policy banks to capitalize on these investment opportunities by deploying Chinese solar and wind technologies to Belt and Road countries and beyond.

© 2018 John Wiley & Sons, Ltd. Accurate and reliable reservoir inflow forecast is instrumental to the efficient operation of the hydroelectric power systems. It has been discovered that natural and anthropogenic aerosols have a great influence on meteorological variables such as temperature, snow water equivalent, and precipitation, which in turn impact the reservoir inflow. Therefore, it is imperative for us to quantify the impact of aerosols on reservoir inflow and to incorporate the aerosol models into future reservoir inflow forecasting models. In this paper, a comprehensive framework was developed to quantify the impact of aerosols on reservoir inflow by integrating the Weather Research and Forecasting model with Chemistry (WRF-Chem) and a dynamic regression model. The statistical dynamic regression model produces forecasts for reservoir inflow based on the meteorological output variables from the WRF-Chem model. The case study was performed on the Florence Lake and Lake Thomas Alva Edison of the Big Creek Hydroelectric Project in the San Joaquin Region. The simulation results show that the presence of aerosols results in a significant reduction of annual reservoir inflow by 4–14%. In the summer, aerosols reduce precipitation, snow water equivalent, and snowmelt that leads to a reduction in inflow by 11–26%. In the spring, aerosols increase temperature and snowmelt which leads to an increase in inflow by 0.6–2%. Aerosols significantly reduce the amount of inflow in the summer when the marginal value of water is extremely high and slightly increase the inflow in the spring when the run-off risk is high. In summary, the presence of aerosols is detrimental to the optimal utilization of hydroelectric power systems.

Dam removals in the United States continue to accelerate in pace and scope, but no national analyses have examined how removed dams compare with existing dam stock. Here, we review and analyse the best available national data on dams from the National Inventory of Dams (NID), dam removals from American Rivers, the U.S. Geological Survey, and the National River Restoration Science Synthesis databases to compare trends and characteristics of removed versus existing dams in the United States. If historical trends continue, by 2050 the United States can expect between 4,000 and 36,000 total removals, including 2,000–10,000 removals of NID dams. Best‐fit regression models estimate total costs between $50.5 million and $25.1 billion (mean $10.5 billion, median $416.5 million) for all removals and $29.6 million to $18.9 billion (mean $7.2 billion, median $285 million) for NID removals, a significant cost savings over present stated dam rehabilitation needs. Structural characteristics and ages of documented removals are not representative of existing dams, with privately owned hydroelectric dams subject to public oversight and water supply dams the most disproportionately removed. We conclude that dam removal science would benefit from the creation of an interdisciplinary framework for studying dams as environmental, social, and technological interventions, facilitated by transparent datasets around dams and removals and reflexive research approaches that combine statistical approaches with place‐based analyses.

Most economic initiatives and infrastructure projects in Brazilian Amazonia have social benefits that are small and ephemeral, while their socioenvironmental impacts are severe. More sustainable forms of development are inhibited by barriers such as a decision†making system with heavy influence (including corruption) from actors with interests in nonsustainable activities. These interests have driven a recent surge of legislative threats to environmental licensing. Better alternatives exist for many destructive forms of “development†projects. Examples include transport using rivers (rather than building highways) and electricity generation from Brazil's vast solar and wind resources (rather than hydroelectric dams). Traditional rural populations could receive support from programs that tap the value of the Amazon forest's environmental services, but institutional mechanisms are in their infancy, among challenges that include differing political interests of countries providing environmental services and those that might pay for them, lack of data and a “theoretical battlefield†regarding accounting for benefits.

In the wake of the COP21 conference in Paris, the transition to a low-carbon energy supply remains a central issue on the political agenda. The deployment of renewable energies is often challenged by multiple issues (e.g., public acceptance, landscape protection, and so forth). Political actors try to overcome such challenges with various measures; however, the policy instruments used vary greatly in their strength. This article questions what factors lead to the adoption of strong policy instruments promoting hydroelectricity. Explanatory factors are derived from Kingdon’s multiple streams framework and are analyzed with fuzzy-set qualitative comparative analysis within the Swiss cantons. The findings show that the strength of policy promoting hydroelectricity depends on the conjunction of mainly two factors: ambitious climate targets and an already well-established hydroelectricity sector that generates large tax revenues for the cantons. Depending on the context, the strength of left-wing and green parties as well as the current level of exploitation play an important role with the aforementioned factors.

Conventional methods for estimating whole-stream metabolic rates from measured dissolved oxygen dynamics do not account for the variation in solute transport times created by dynamic flow conditions. Changes in flow at hourly time scales are common downstream of hydroelectric dams (i.e., hydropeaking), and hydrologic limitations of conventional metabolic models have resulted in a poor understanding of the controls on biological production in these highly managed river ecosystems. To overcome these limitations, we coupled a two-station metabolic model of dissolved oxygen dynamics with a hydrologic river routing model. We designed calibration and parameter estimation tools to infer values for hydrologic and metabolic parameters based on time series of water quality data, achieving the ultimate goal of estimating whole-river gross primary production and ecosystem respiration during dynamic flow conditions. Our case study data for model design and calibration were collected in the tailwater of Glen Canyon Dam (Arizona, U.S.A.), a large hydropower facility where the mean discharge was 325 m3 s−1 and the average daily coefficient of variation of flow was 0.17 (i.e., the hydropeaking index averaged from 2006 to 2016). We demonstrate the coupled model's conceptual consistency with conventional models during steady flow conditions, and illustrate the potential bias in metabolism estimates with conventional models during unsteady flow conditions. This effort contributes an approach to solute transport modeling and parameter estimation that allows study of whole-ecosystem metabolic regimes across a more diverse range of hydrologic conditions commonly encountered in streams and rivers.

The number of hydroelectric dams used for energy production and the cultivation of sugar cane crops for ethanol production have increased significantly in the southeastern region of Brazil. These land use/land cover changes (LULCC) associated with energy policy can affect landscape changes over a range of temporal and spatial scales. This article focuses on how human-landscape interactions have influenced geomorphological dynamics in the lower course of the Piracicaba River for two different scenarios that represent pre-dam and post-dam conditions in 1962 and 2007, respectively, and the expansion of sugar cane crops after 1975. This assessment was performed by mapping land use and geomorphological changes in the study area in the 1962 and 2007 scenarios, in addition to quantifying the sedimentation rates upstream from the Barra Bonita Reservoir using 210Pb. The main land uses identified for the 1962 scenario were pastures, meadows, annual crops and forests. However, the main land use change was the expansion of sugar cane cropland from 4 to 39%. In the 1962 scenario, the lower course of the Piracicaba River had a predominantly meandering pattern, and there were pronounced alluvial plains in the region. In the 2007 scenario, oxbow lakes were not mapped, and the river terraces were reduced in area due to the construction of the Barra Bonita Reservoir. The changes in the sedimentation rates indicate an association between the construction of the Barra Bonita Reservoir and the expansion of sugar cane crops. It was therefore not possible to assess the specific influences of each anthropogenic change on the sedimentation processes, reinforcing that the human-landscape systems in Sao Paulo State associated with energy policy are complex.

Worldwide populations of freshwater eels have declined with one of the contributing causes related to mortality during passage through hydropower turbines. An inherent trade‐off underlies turbine management where the competing demand for more hydropower comes at the expense of eel survival. A win–win solution exists when an option performs better on all competing demands compared to other options. A predictive model for eel migration based on a recent telemetry study was used to develop decision rules for turbine management in the Shenandoah River system. The performance of alternative decision rules was compared to the status quo policy to search for win–win solutions. Decision rules were defined by the probability of eel movement and were evaluated by the probabilities of false positive and false negative errors. The exact value of the cut‐off probability used in the decision rule will need to be determined through negotiation between stakeholders, but a range of cut‐off probabilities resulted in a win–win situation with both reduced eel mortality and increased turbine operation relative to the current shutdown strategy. Monitoring the implementation is needed to evaluate and update the predictive model and to refine the decision rule. Although the decision is framed for the Shenandoah River system, the analytical approach could be used to develop decision rules for turbine shutdown policy in other areas.

Belo Monte is one of the most divisive dams in Brazilian history, becoming entangled in a thirty-year struggle between pro- and anti-dam interests over the role of the facility within a complex web of Brazilian development and the future of the Brazilian Amazon. This research explores how the proponents of Belo Monte have adopted a number of policy frames as a means of deflection, to divide the opposition and legitimize the project. It investigates this claim by analyzing speeches given within the Brazilian Câmara dos Deputados and the public speeches of high-level politicians. These sources, organized around a framework previously identified by Ahlers et al. (2014), show that the government and individual politicians have used a variety of framing devices to legitimize the hydroelectric facility. Principal methods of framing used also demonstrate how contemporary narratives (e.g. sustainability) have been employed to deflect opposition criticism and widen the scheme's perceived beneficiaries. In doing so, this paper demonstrates how the transformation represented by Belo Monte encompassed not only a process of engineering but also a re-articulation of the complex and its role in modern Brazil.