scholarly journals Effects of high-altitude reservoirs on the structure and function of lotic ecosystems: a case study in Italy

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Antonio Petruzziello ◽  
Luca Bonacina ◽  
Francesca Marazzi ◽  
Silvia Zaupa ◽  
Valeria Mezzanotte ◽  
...  
Keyword(s):  
Organic Matter ◽  
High Altitude ◽  
Thermal Regime ◽  
Power Plants ◽  
Stream Water ◽  
Management Strategies ◽  
Macroinvertebrate Communities ◽  
Hydroelectric Power ◽  
Breakdown Rate ◽  
Lotic Ecosystems

AbstractAlpine and pre-alpine lotic ecosystems are often remote and not affected by humans, which makes them some of the world’s most pristine ecosystems. However, their status is often altered by the presence of reservoirs that are built to fulfill agricultural needs and hydroelectric demands. These reservoirs also disrupt stream continuity and alter the magnitude, timing, and frequency of natural flows. The present work assessed how high-altitude reservoirs affect the riverine ecosystems focusing on the following: (i) the macroinvertebrate communities, (ii) the breakdown of organic matter, and (iii) the thermal regime. Stretches altered by high-altitude reservoirs had the best conditions for most macroinvertebrate families due to a more stable flow conditions. The breakdown rate of coarse particulate organic matter was not affected by high-altitude reservoirs but its availability was higher in altered compared to pristine stretches. The presence of hydroelectric power plants modified the stream thermal regime. Reservoirs mitigate the atmospheric influence on stream water temperature while run of the river plants strengthen it in the diverted stretches. Where both these alterations were present, the thermal regime of the stream was more similar to the natural ones compared to stretches subjected to only one kind of alteration. This research showed how river impoundment alters the structure of macroinvertebrate communities and the function of the downstream lotic ecosystems and can provide the basis to correctly guide management strategies for lotic ecosystems affected by hydrological alterations.

scholarly journals Researches of the kharanorsk reservoir ecosystem according to the outcomes of the plankton primary production assessment

2021 ◽  
pp. 42-54
Author(s):  
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Column ◽  
Power Plants ◽  
Thermal Power ◽  
Central Zone ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Daily Production ◽  
Littoral Zones

This article presents the results of the assessment of production and destruction processes in the ecosystem of the Kharanorsk reservoir-cooler, used as a cooling pond of the Kharanorsk hydroelectric power station. The content of dissolved oxygen in the water of the reservoir is ubject to seasonal dynamics corresponding to biochemical processes occurring in the reservoir. In spring and autumn, the concentration of dissolved oxygen is in the range from 12.6 to 14.2 mg / L. We attribute the decrease in oxygen content in the summer month to 9.6 mg / L with an increase in air temperature and with the thermal effect of thermal power plants, which in total lead to an intensification of the processes of biochemical decomposition of organic and oxidation of mineral substances. High production capabilities of the ecosystem in both the central and littoral zones were found in July in the surface horizons of the water column (3.53 mgO2 / L – littoral; 3.92 mgO2 / L – center). The formation of organic matter in the direction “surface horizon - bottom layers” of the water column in the central zone decreases due to a decrease in the transparency of the water column. The cessation of the production of organic matter by phytoplankton in the bottom layers of the littoral zone we associate with the competitive relationship of bottom organisms in the use of nutrients. It has been established that the rate of daily production increases from April to July and begins to fall in October, but remains high relative to spring indicators in both the central and littoral zones of the reservoir. The studies are necessary for subsequent environmental monitoring studies, as well as for making managerial decisions to maintain the sustainability of the reservoir ecosystem.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

scholarly journals Analytical Approach to Sampling Estimation of Underwater Tunnels Using Mechanical Profiling Sonars

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1900
Author(s):  
Vitor Augusto Machado Jorge ◽  
Pedro Daniel de Cerqueira Gava ◽  
Juan Ramon Belchior de França Silva ◽  
Thais Mancilha ◽  
Waldir Vieira ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Hydroelectric Power ◽  
Large Power ◽  
Unmanned Underwater Vehicles ◽  
Power House ◽  
Simulated Environment ◽  
Sonar Sensor ◽  
Power Plant Operation ◽  
Plant Power

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.

scholarly journals Comparison of solar power measurements in alpine areas using a mobile dual-axis tracking system

2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Jelenko Karpić ◽  
Ekanki Sharma ◽  
Tamer Khatib ◽  
Wilfried Elmenreich
Keyword(s):  
High Altitude ◽  
Peak Power ◽  
Power Plants ◽  
Low Cost ◽  
Elevation Angle ◽  
Test Site ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Photovoltaic Power ◽  
Power Point

Abstract The rising demand for sustainable energy requires to identify the sites for photovoltaic systems with the best performance. This paper tackles the question of feasibility of photovoltaic power plants at high altitude. A direct comparison between an alpine and an urban area site is conducted in the south of Austria. Two low-cost automatic photovoltaic power measurement devices with dual-axis sun tracking and maximum power point tracking are deployed at two test sites. The system periodically performs a scan over the southern semihemisphere and executes maximum power point adjustment in order to assess the performance for a given direction. The gathered data shows a higher photovoltaic power yield in the higher altitude test site. Furthermore, the high altitude photovoltaic power as a function of azimuth and elevation angle appears to be not only higher but also more flat than in lower altitudes. This indicates a lower power loss in case of deviation from the optimal solar angles. The results show that even on low-cost hardware a difference in photovoltaic power can be observed, even though in this experiment it amounts to less than 5% increase of peak power in higher altitudes. However, the measured peak powers on the mountain are more stable and therefore closer to a constant level than the heavily fluctuating peak power values at the low altitude site. Additionally, a slight shift in optimal elevation angles between altitudes can be observed, as the optimum angle turns out to be lower on the high altitude site. This angle shift could be caused by snow reflections on the mountainous test site.

Water quality impacts of small hydroelectric power plants in a tributary to the Pantanal floodplain, Brazil

2021 ◽  
Author(s):  
Rúbia Fantin Cruz ◽  
Stephen K. Hamilton ◽  
Hans M. Tritico ◽  
Ibraim Fantin‐Cruz ◽  
Daniela Maimoni Figueiredo ◽  
...  
Keyword(s):  
Water Quality ◽  
Power Plants ◽  
Hydroelectric Power ◽  
Hydroelectric Power Plants

Application of Intelligent Technological Systems in Order to Increase Efficiency of the Lock Chamber System in Hydro Power Plants

2015 ◽  
Vol 806 ◽  
pp. 64-73
Author(s):  
Aleksandar Vujović ◽  
Zdravko Krivokapić ◽  
Jelena Jovanović
Keyword(s):  
Power Plants ◽  
Hydroelectric Power Plant ◽  
Global Market ◽  
Real System ◽  
Hydroelectric Power ◽  
Initial State ◽  
Hydro Power ◽  
Lock Chamber ◽  
Levels Of Automation ◽  
Hydro Power Plants

The paper is a result of research at the Mechanical Engineering Faculty in Podgorica and represents the aspiration of authors to combine scientific and technical experience in order to achieve improvement in a real system. It is a complex system of lock chambers in a hydroelectric power plant. Based on a detailed analysis of the initial state, through the process modeling of complex real system, the authors identify possible areas where the intervening and applying modern systems with greater flexibility is necessary to achieve higher levels of automation. Also, proposed in the paper are measures for ensuring the security of information that rise system performance to a higher level compared to the competition and create an advantage in the global market.

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