Construction Of Hydropower Plants Research Articles

A Multicriteria Evaluation of Sustainable Riparian Revegetation with Local Fruit Trees around a Reservoir of a Hydroelectric Power Plant in Central Brazil

The construction of hydropower plants often requires the flooding of large land areas, causing considerable alterations in the natural environment. In the region surrounding the reservoir of the Corumbá IV hydroelectric plant, located in the Cerrado region of Central Brazil, two types of soil predominate, classified as Dystroferric Red Latosol and Dystroferric Haplic Cambisol. The plant owners have to restore the degraded biome after the flooding of the margins caused by the filling of the reservoir. An experiment was carried out with fifteen native species, selected for having ideal phytosociological properties. Nine of them showed a survivability considered satisfactory in a planting situation, with a view to large-scale planting. Assuming that the planting of native fruit trees can be a quick solution to the attraction and preservation of wildlife, it would therefore provide sustainable riparian revegetation around the reservoir. We adopted the SIMOS technique to rank the criteria based on four morphological features and a Fuzzy AHP model to rank the contributions of the nine fruit tree species to the sustainable restoration of part of the riparian vegetation cover around the reservoir. In practical terms, we concluded that the soil types did not have any influence on tree survival after two years of growth, but the native trees’ morphological features varied among the species. These findings simplify the large-scale planting of seedlings that must be carried out by the operator in the riparian forest around the reservoir.

A new soft computing model for daily streamflow forecasting

Accurate stream flow quantification and prediction are essential for the local and global planning and management of basins to cope with climate change. The ability to forecast streamflow is crucial, as it can help mitigate flood risks. Long-term stream flow data records are needed for hydropower plant construction, flood prediction, watershed management, and long-term water supply use. An accurate assessment of streamflow is considered as very challenging and critical tasks. A new predicting model is developed in this research, combining the technique of sunflower optimization (SFA) as an evolutionary algorithm with the multi-layer perceptron (MLP) algorithm to predict streamflow in Malaysia's Jam Seyed Omar (JSO) and Muda Di Jeniang (MDJ) stations. Principal component analysis (PCA) was performed on Q (t) (t: the number of the current day) before model creation to pick essential inputs for a maximum of 6 lags. With the classical MLP and two other hybrid MLP models (MLP-particle swarm optimization (MLP-PSO) and MLP-genetic algorithm (MLP-GA)), the results of the MLP-sunflower algorithm (SFA) were benchmarked. As compared to other models, the MLP-SFA could be able to reduce the Root Mean Square Error (RMSE) by a value of between 12 and 21% at the JSO station and between 8 and 24% at the MDJ station. In conclusion, this research found that combining MLP with optimization algorithms improved the precision of the stand-alone MLP model, with SFA integration being the most efficient.

НОРМАТИВНО-ПРАВОВІ АСПЕКТИ ВИКОРИСТАННЯ В УКРАЇНІ ГІДРОЕНЕРГЕТИЧНОГО ПОТЕНЦІАЛУ ЗВОРОТНИХ ВОД ТЕХНОЛОГІЧНИХ ПРОЦЕСІВ ЗА «ЗЕЛЕНИМ» ТАРИФОМ НА ГЕНЕРОВАНУ ЕЛЕКТРОЕНЕРГІЮ

Гідроенергетичний потенціал малих річок України, з урахуванням природоохоронних обмежень на використання води стоку річки для виробництва електроенергії та використання територій для спорудження малих ГЕС, сягає рівня 375 МВт з річним обсягом виробництва електроенергії близько 1270 млн кВт·год/рік. Існують додаткові можливості збільшення потенціалу малої гідроенергетики в результаті використання скидного потенціалу зворотних вод технологічних процесів (водопостачання питної води, водовідведення, зворотні води гірничо-збагачувальних комбінатів, очисних споруд міст та підприємств). При цьому генерування електроенергії здійснюється за відсутності негативного впливу на флору і фауну, оскільки у зворотних водах відсутня риба, річкові тварини, рідкісні птахи, немає потреби в побудові греблі, нового водосховища, не затоплюються навколишні території. Будівництво малих ГЕС на введених в дію спорудах водопостачання та водовідведення сприяє модернізації існуючого об’єкта (ремонт або заміна окремих елементів) та підвищенню його надійності в результаті встановлення сучасної автоматизованої системи управління та моніторингу. Але в переважній більшості випадків, за винятком водопостачання питної води, зворотні води містять значну кількість домішок і хімічних сполук, що значно збільшує питомі витрати на обладнання. Експлуатація обладнання в агресивному середовищі зменшує рентабельність цих проєктів. Тому отримання «зеленого» тарифу на вироблену електроенергію такими малими ГЕС слугує майже єдиною мотивацією для приватних інвесторів. Проте в чинних нормативно-правових актах відсутнє однозначне трактування умов установлення «зеленого» тарифу для ГЕС на зворотних водах. У статті визначено нормативно-правові аспекти для встановлення «зеленого» тарифу на генеровану електроенергію при використанні гідроенергетичного потенціалу зворотних вод технологічних процесів. Наведено короткий опис реалізованого пілотного проєкту малої ГЕС на стічних водах міських очисних споруд на території України, для якої встановлено «зелений» тариф на вироблену електроенергію. Бібл. 17, табл. 2, рис. 1.

ENERGIZING COMMUNITIES THROUGH PARTNERSHIPS WITH EXTERNAL ACTORS: SMALL-SCALE HYDROPOWER PROJECTS IN JAPAN

This study aims to specify the contextual conditions that allow for the success of community renewable energy projects, against the background of the expanding use of renewable energy. It analyzes cases where farmers invested in organizations to establish ownership of hydropower plants in the Chugoku region, Japan. Community renewable energy projects derived from local initiatives to provide an alternative energy resource and serve as a catalyst for rural development. However, the costs of small hydropower plant construction and the expert knowledge required for their operation could hinder the diffusion of the technology. Population decline and aging in rural communities also constrain the development of community renewable energy projects. This study presents cases that illuminate the conditions enabling these organizations to succeed in securing the necessary resources for the operation of their renewable energy plants. The survey illustrates how studied organizations have opted to collaborate with external actors to construct or refurbish their plants. The findings indicate that as building partnerships with external actors often becomes essential, it is vital to develop a business-minded framework in which both communities and external actors can financially benefit from introducing small hydropower projects. The cases also reveal that in building collaborative relationships, broad disparities exist between communities and external actors in financial power and expert knowledge, which give the latter substantial advantages in negotiations. An additional important claim derived is that, for an effective partnership that enables a successful community renewable energy project, a third party with expert knowledge and the ability to audit partnership-building processes could play a crucial role in securing community initiatives and independence.

Dynamic Optimization for Analyzing Effects of Multiple Resource Failures on Project Schedule Robustness

This study develops hybrid modeling and algorithmic frameworks for analyzing the mutual effects of multiple sources of uncertainty on the quality and the robustness of construction schedules. To cope with multiple sources of disruptions, i.e., random resource failures and severe weather conditions, this paper develops a simulation-optimization model that aims to generate delay resistant project schedules. The Variable Neighborhood Search (VNS) is hybridized with an event-driven simulation framework to generate efficient and robust solutions for computationally expensive resource-constrained project scheduling problems (RCPSP). The simulation experiments have been carried out by a flexible modeling framework that can be adopted by project experts to design construction schedules subject to the uncertainty associated with the multiple resource failure. The problem is mathematically formulated as a bi-objective optimization model aiming to minimize the project makespan and maximize a novel surrogate robustness function simultaneously. The computational results of the proposed VNS method have been compared with those obtained from the commercial optimization solvers. The simulation-optimization model’s application is demonstrated through a case study of the hydropower plant construction project with multiple renewable and non-renewable resources. Based on an extensive statistical analysis of real-life scenarios, this study contributes to a trade-off analysis of project makespan and robustness in construction projects. The t-test statistical analysis results indicate the significance of the project’s average delay reduction by implementing the robust project schedule. The outcomes confirm that the designed framework can generate a more efficient project schedule with a higher rate of protection compared with the existing robust approaches.

Governance of Water in Southern Chile: An Analysis of the Process of Indigenous Consultation as a Part of Environmental Impact Assessment

The management and organization of water resources shapes complex territorial scenarios. This is seen in south-central Chile, where the construction of hydropower plants in Indigenous territories has strained relations between the state, the Mapuche people and hydropower companies. We analyze the Indigenous consultation process to identify the relations between actors and the role of state institutions to evaluate the extent to which these facilitate collective action. Using a case study methodology and qualitative analysis, we identify challenges to water governance, which relate to the degree of heterogeneity of communities; power inequalities within the consultation process and their influence on structures of decision-making.

A review of research on the Lemanea genus in Serbia

Abstract The first data on the Lemanea genus in Serbia come from the late 20th century. Only one species, L. fluviatilis, was reported from 10 localities in Serbian riverine ecosystems between 1991 and 2017. Extensive research on this genus was performed in April–November 2017–2019, surveying 150 localities in 97 upland and mountain rivers. During this study period, the Lemanea genus was recorded at 14 localities in 12 rivers, while it disappeared from five previously reported localities. A total of four taxa were identified: Lemanea fucina, L. rigida, Lemanea sp. and L. fluviatilis. Lemanea fucina and L. rigida were recorded in Serbia for the first time. L. fluviatilis was the most common taxon. Our research confirmed that Lemanea species prefer similar specific environmental conditions. These species were found in temperate, soft or moderately hard, well-oxygenated and weakly alkaline waters, with low, moderate or high conductivity, and in waters with low content of inorganic nutrients. Due to their sensitivity to changes in environmental conditions, Lemanea species are exposed to negative anthropogenic impact leading to the degradation of their habitats. Intensive construction of small hydropower plants has threatened most habitats of the Rhodophyta species in the last few years.

Environmental Challenges in Regions: Analysis and Measures to Reduce Potential Risks

The environmental deterioration in Russia requires the identification and analysis of the main challenges facing the country and its individual regions in this sphere. Additionally, it is necessary to find ways to overcome these problems. Th e issu e is particularly relevant for resource regions where new economic activities develop. the Lower Angara region in Krasnoyarsk krai is one of such regions. The study considers the environmental problems in connection with the socio-economic conditions of a particular territory. I used the method of economic and mathematical modelling based on the author’s models for optimising environmental protection measures. The research combines the obtained results to built a comprehensive model of the future ecological situation that may develop in the region. The analysis discovered various causes of environmental challenges. The first reason is planning exxessive output at individual facilities. In particular, calculations have shown that in the conditions of the Lower Angara region, the unit capacity of the pulp and paper industry should not exceed 300–350 thousand tonnes (instead of the planned 720 thousand tonnes); the capacity of the aluminum plant should not exceed 200–250 thousand tonnes (instead of 600 thousand tonnes). Second, an excessive concentration of production in certain areas (primarily, in Boguchansky and Kodinsky industrial hubs) increases the environmental burden. Third, pollution control is complicated by unique production capacities of various facilities that require special purification systems. The fourth reason is the effects of synergism and additivity of contaminants. The fifth cause is the actual and potential negative consequences of the construction of hydropower plants on the Angara and Yenisei rivers. The results of this research can be used for creating a strategy for the integrated development of territorial economic systems to organise environmental protection activities and substantiate management decisions at the regional and local levels of governance.

Progress for On-Grid Renewable Energy Systems: Identification of Sustainability Factors for Small-Scale Hydropower in Rwanda

In Rwanda, most small-scale hydropower systems are connected to the national grid to supply additional generation capacity. The Rwandan rivers are characterized by low flow-rates and a majority of plants are below 5 MW generation capacity. The purpose of this study is to provide a scientific overview of positive and negative factors affecting the sustainability of small-scale hydropower plants in Rwanda. Based on interviews, field observation, and secondary data for 17 plants, we found that the factors contributing to small-scale hydropower plant sustainability are; favorable regulations and policies supporting sale of electricity to the national grid, sufficient annual rainfall, and suitable topography for run-of-river hydropower plants construction. However, a decrease in river discharge during the dry season affects electricity production while the rainy season is characterized by high levels of sediment and soil erosion. This shortens turbine lifetime, causes unplanned outages, and increases maintenance costs. Further, there is a need to increase local expertise to reduce maintenance cost. Our analysis identifies environmental factors related to the amount and quality of water as the main current problem and potential future threat to the sustainability of small-scale hydropower. The findings are relevant for energy developers, scholars, and policy-makers in Rwanda and East Africa.

Integrated Impact Assessment for Sustainable Hydropower Planning in the Vjosa Catchment (Greece, Albania)

Mitigating climate change, while human population and economy are growing globally, requires a bold shift to renewable energy sources. Among renewables, hydropower is currently the most economic and efficient technique. However, due to a lack of impact assessments at the catchment scale in the planning process, the construction of hydropower plants (HPP) may have unexpected ecological, socioeconomic, and political ramifications in the short and in the long term. The Vjosa River, draining parts of Northern Greece and Albania, is one of the few predominantly free-flowing rivers left in Europe; at the same time its catchment is identified an important resource for future hydropower development. While current hydropower plants are located along tributaries, planned HPP would highly impact the free-flowing main stem. Taking the Vjosa catchment as a case study, the aim of this study was to develop a transferable impact assessment that ranks potential hydropower sites according to their projected impacts on a catchment scale. Therefore, we integrated established ecological, social, and economic indicators for all HPP planned in the river catchment, while considering their capacity, and developed a ranking method based on impact categories. For the Vjosa catchment, ten hydropower sites were ranked as very harmful to the environment as well as to society. A sensitivity analysis revealed that this ranking is dependent upon the selection of indicators. Small HPP showed higher cumulative impacts than large HPP, when normalized to capacity. This study empowers decision-makers to compare both the ranked impacts and the generated energy of planned dam projects at the catchment scale.

Influence of the Vilyui hydropower plant on the regime of the Vilyui river

Based on the analysis and comparison of the Vilyui river regime in the natural and regulated state, the article reveals the features of changes in the annual distribution of runoff, level and ice regimes and the regime of solid runoff. To assess the consequences of the impact of large hydroelectric power stations in the Far North, comprehensive studies of the Vilyui river basin were conducted. Vilyui hydroelectric station is the first hydroelectric power station in the permafrost zone. The reservoir is completely located within the Republic of Sakha (Yakutia). Despite the low level of development of water resources in the Far East, the prospects for the construction of traditional hydropower plants remain. The hydropower potential of the republic is estimated at 283 billion kWh, which is 66 % of the total hydropower potential of the Far East region. The construction and operation of hydropower plants on rivers leads to fundamental changes in the natural conditions of the river. The results of the study show that flow regulation by large reservoirs is the main factor of anthropogenic disturbances in the flow volume and water regime of the Arctic rivers. To date, the diverse effects of river regime changes after the construction of a hydroelectric power station on the territory of permafrost are not fully considered in either design or prospective planned developments. The importance of accounting and studying the consequences of flow regulation can be judged by the complex economic problems that arose after the construction of hydropower facilities in the European part of Russia. In this regard, a comprehensive study of changes in environmental conditions in the territory of permafrost distribution after regulation of river flow by large reservoirs is one of the most important tasks.

Empirical Analysis and Geomechanical Modelling of an Underground Water Reservoir for Hydroelectric Power Plants

The European Union policy of encouraging renewable energy sources and a sustainable and safe low-carbon economy requires flexible energy storage systems (FESSs), such as pumped-storage hydropower (PSH) systems. Energy storage systems are the key to facilitate a high penetration of the renewable energy sources in the electrical grids. Disused mining structures in closed underground coal mines in NW Spain have been selected as a case study to analyze the construction of underground pumped-storage hydropower (UPSH) plants. Mine water, depth and subsurface space in closured coal mines may be used for the construction of FESSs with reduced environmental impacts. This paper analyzes the stability of a network of tunnels used as a lower water reservoir at 450 m depth in sandstone and shale formations. Empirical methods based on rock mass classification systems are employed to preliminarily design the support systems and to determinate the rock mass properties. In addition, 3D numerical modelling has been conducted in order to verify the stability of the underground excavations. The deformations and thickness of the excavation damage zones (EDZs) around the excavations have been evaluated in the simulations without considering a support system and considering systematic grouted rock bolts and a layer of reinforced shotcrete as support system. The results obtained show that the excavation of the network of tunnels is technically feasible with the support system that has been designed.

Improving survival: injury and mortality of fish struck by blades with slanted, blunt leading edges

Compact turbines offer potential to reduce hydropower plant construction costs, but conventional turbine blade designs endanger entrained fish due to high blade strike speeds and thin leading edges. We evaluated the potential for combined blade leading edge slant and large leading edge thickness to increase strike survival. Rainbow trout (Oncorhynchus mykiss) were subjected to strikes with 100 mm thick blade analogues. At 10 m/s, strikes at fish length to blade leading edge thickness ratio (L/t) of 2 resulted in 98% survival at a location along the blade witha 30° slant relative to the tangential direction, compared to 26.8% survival at a location with 90°slant. For L/t 1.14-2, survival was found to be sensitive to location of strike within the mid-body region, determined from high-speed video. Strikes of 200 mm fish at 10 m/s resulted in 68% survival when body strike location was 0.58 (near caudal), and 7.9% when body strike location was 0.36 (near head). These results are consistent with previous trends and indicate opportunities to improve turbine blade design for greater entrained fish survival at higher turbine speeds, at both low head (<30 m) and high head projects.

Simulation of the Potential Impacts of Projected Climate Change on Streamflow in the Vakhsh River Basin in Central Asia under CMIP5 RCP Scenarios

Millions of people in Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan are dependent on the freshwater supply of the Vakhsh River system. Sustainable management of the water resources of the Vakhsh River Basin (VRB) requires comprehensive assessment regarding future climate change and its implications for streamflow. In this study, we assessed the potential impacts of projected climate change scenarios on the streamflow in the VRB for two future periods (2022–2060 and 2061–2099). The probable changes in the regional climate system were assessed using the outputs of five global climate models (GCMs) under two representative concentration pathways (RCPs), RCP4.5 and RCP8.5. The probable streamflow was simulated using a semi-distributed hydrological model, namely the Soil and Water Assessment Tool (SWAT). Evidence of a significant increase in the annual average temperature by the end of the 21st century was found, ranging from 2.25 to 4.40 °C under RCP4.5 and from 4.40 to 6.60 °C under RCP8.5. The results of three GCMs indicated a decreasing tendency of annual average precipitation (from −1.7% to −16.0% under RCP4.5 and from −3.4% to −29.8% under RCP8.5). Under RCP8.5, two GCMs indicated an increase (from 2.3% to 5.3%) in the average annual precipitation by the end of 2099. The simulated results of the hydrological model reported an increasing tendency of average annual streamflow, from 17.5% to 52.3% under both RCPs, by the end of 2099. A shift in the peak flow month was also found, i.e., from July to June, under both RCPs. It is expected that in the future, median and high flows might increase, whereas low flow might decrease by the end of 2099. It is concluded that the future seasonal streamflow in the VRB are highly uncertain due to the probable alterations in temperature and precipitation. The findings of the present study could be useful for understanding the future hydrological behavior of the Vakhsh River, for the planning of sustainable regional irrigation systems in the downstream countries, i.e., Uzbekistan and Turkmenistan, and for the construction of hydropower plants in the upstream countries.

Effect of Head Variations on Performance Four Sizes of Blowers as Turbines (BAT)

Piko hydro power plant construction using water turbines is still small. One of the challenges is that water turbines are not sold freely in the market, to get them people must order in advance so that the price of turbines becomes expensive. The purpose of this experimental study is to analyze the performance of blowers as turbines (BAT). The research results are known, that centrifugal blowers was successfully functioned as a water turbine. The smaller the size of the blower results in better performance. The performance of 2-inch blowers is superior compared to 2.5-inch, 3-inch and 4-inch blowers. The maximum power and efficiency of a 2-inch BAT is 583.02 Watt and 50.90% occurs at 14 m head, 8.34 L/s discharge and 800 rpm rotation. The mathematical equation of the BAT efficiency curve is y = 105.1x 3 − 363.6x 2 + 398.5x − 89.72. BAT applicative research in the community needs to be carried out by subsequent researchers to find out the challenges and ease of using centrifugal blowers as turbines.

An assessment of environmental flow for modelling the operating conditions of Mongolian hydropower plants in the transboundary basin of the Selenga River

The decision of Mongolia’s Government to implement the projects for the construction of hydropower plants (HPPs) in the transboundary basin of the Selenga River caused the need to study their possible impact on the Russian part of the basin and Lake Baikal. To assess the impact of planned in Mongolia HPPs on the territory of the Russian Federation (water resources and ecosystem), we have studied the expected changes in the yearly hydrological regimes due to flow regulation. A methodology developed at the Melentiev Energy Systems Institute (MESI) allows integrating various models (hydrological, energy, environmental, etc.) into a single system. We have employed this system to model the parameters of the planned HPPs reservoirs and their regulation modes, as well as the deviations of hydrological regimes of Selenga River due to the HPPs construction from those under natural conditions. The concept of “environmental flow” is used to assess changes in the intra-annual hydrological regime of a river. We determine the boundaries of the environmental flow for each month based on an analysis of a variety of biotic and abiotic restrictions for the entire river bed from the border of the Russian Federation to the Selenga River delta.

Feasibility analysis of construction of new hydropower plants in Ukraine taking into account the risk of unused possibilities

The article presents results of feasibility analysis of construction of new hydropower plants in Ukraine according to the Hydropower development program for the period till 2026, which was approved by our Government in 2016. In particular, there are analyzed perspective plans for building the Kakhovka hydropower plant #2 and six new hydropower plants on the river Dniester, as well as developing small hydropower in the country. The feasibility analysis is based on pairwise comparison of alternatives by the criterion of minimum aggregate risk taking into account the risk of unused opportunities. Components of aggregate risks of alternatives are estimated in dimensionless units for water-energy and operability characteristics and costs of commissioning of new hydro aggregates.

On some challenges of environmental impact assessment of small hydropower plants in Ukraine

One of the pressing problems of today is the greening of nature management, which is recognized as one of the fundamental components of the newest concept of “sustainable” development. The Law of Ukraine “On Environmental Impact Assessment”, adopted in 2017, has opened up new opportunities for environmental review and regulation of potentially hazardous activities related to the use of natural resources, with involvement of the general public in decision-making processes.According to this Law, hydropower plants on rivers, regardless of their capacity, are also included in the types of planned activities and objects that can have a significant environmental impact and are subject to environmental impact assessment. Thus, at the legislative level, it is recognized that so-called “small hydropower plants” are capable of adversely affecting the environment and should be considered environmentally and socially dangerous until the opposite is established by the results of the environmental expertise.It is because of the small capacity of hydropower plants in numerous publications of various domestic authors that the idea that small hydropower plants can not adversely affect the environment and are environmentally safe has been formed and continues to be upheld. Due to this, small hydropower has received the status of “green” energy and state supporting in the form of various attenuations, in particular at the expense of “green” tariff. Our analysis of notifications of planned activities that are subject to the environmental impact assessment coming into the Unified Registry for Environmental Impact Assessment and of the environmental impact assessment reports materials shows that private investors are openly abusing these preferences. Notifications of planned activities, environmental impact assessment reports are prepared in a frankly poor and non-professional manner, mostly by persons who are little connected for research or have an opinion on the absolute environmental safety of small hydropower plants. As a result, information provided to the public often turns out to be incomplete, one-sided, distorted, and in some cases, untrue.The article highlights the most pressing problems encountered during the practical implementation of the Law of Ukraine “On Environmental Impact Assessment” regarding the construction and operation of small hydropower plants, which could be in interest of scientific and engineering communities, officials and the public.

Detection and interpretation of recent and historical streamflow alterations caused by river damming and hydropower production in the Adige and Inn river basins using continuous, discrete and multiresolution wavelet analysis

In alpine catchments, fluctuations of river discharge occur at multiple temporal scales due to natural (e.g., snow and glacier melt) and anthropogenic factors (e.g., reservoir and hydropower operation). In the last century, several modifications of the natural flow regime have been observed, originating in the complex interplay between construction of dams for hydropower production, changes in water management policies and climate. In this work, we show that multiresolution analysis via discrete wavelet transform and continuous wavelet transform allow identifying both old breakpoints caused by dam and hydropower plant construction as well as more recent breakpoints caused by changes in hydropower plant operation. According to the detected breakpoints we can differentiate a pre-impact period (natural flow regime), post-impact period (characterized by river damming and hydropower facilities operation) and a last period after the recent detected breakpoints (caused by changes in water management). Moreover, by analyzing streamflow time series and their log transform it is possible to highlight low flow alterations and distinguish the causes of the breakpoints, since they affect different temporal scales. The change point analysis is performed using different mother wavelets: Haar, Daubechies 2 (db2), and Daubechies 20 (db20). Considering the results obtained with the Haar mother wavelet: a total of 14 historical breakpoints in 13 streamflow time series belonging to the Adige and Inn catchments were identified and 93% correspond to metadata associated to river damming and hydropower production; a total of 5 recent breakpoints were identified, which correspond to metadata associated to river damming and hydropower production. In case of the log transform of the streamflow: 32 historical breakpoints were identified and 100% confirmed by metadata; 20 recent breakpoints were detected and 83% correspond to metadata. The uncertainty in the temporal location is investigated computing the mean difference between detected breakpoint temporal location and metadata and is generally smaller than 1 year. This work shows that change point analysis performed using wavelet transform allows us to differentiate and correctly locate in time most of change points in streamflow variability that can be associated to river damming and hydropower production.

How Relevant Are Non-Use Values and Perceptions in Economic Valuations? The Case of Hydropower Plants

The construction of hydropower plants, particularly of large ones, is far from being a consensual decision: advocates defend their construction based on the unquestionable benefits hydropower provides, while critics argue that these facilities are far from harmless and cause adverse impacts on the environment, being not only against the construction but also demanding the destruction of existing ones. We review a selection of recent empirical studies concerning impacts of hydropower developments, to make a case for the consideration of non-use values in the economic valuation of the environmental and social impacts of hydropower plants, through the use of non-market valuation methodologies. Additionally, we present data from a case study of hydropower economic valuation, where different subgroups of the population with differing degrees of contact and familiarity with hydropower rate their perception of impacts. Respondents with more contact are less penalizing of hydropower than other respondents. We conclude that non-use values are non-negligible and can be valued through stated preference methods, but researchers should take into consideration perceptions and the role of users and non-users. Non-use values should thus not be neglected by policy makers and regulators at the planning and public consultation stages or as part of the decommissioning decision.