scholarly journals Observations on aquatic Macrophyte Dynamics In the Reservoir Of The Balbina Hydroelectric Powerplant, Amazonas State, Brazil

1999 ◽  
Vol 29 (2) ◽  
pp. 243-265 ◽  
Author(s):  
Ilse WALKER ◽  
Roberto MIYAI ◽  
M. D. Amaral de MELO
Keyword(s):  
Eichhornia Crassipes ◽  
Dominant Species ◽  
Annual Variation ◽  
Aquatic Macrophyte ◽  
Hydroelectric Power Plant ◽  
Water Levels ◽  
Hydroelectric Power ◽  
Short Period ◽  
Drift Wood ◽  
Amazonas State

Between 1991 and 1995 aquatic macrophyte composition was observed in the lower part of the reservoir of the hydroelectric power plant of Balbina (Amazonas, Brazil). After closure of the dam in 1987, vegetation cover - mostly Eichhornia crassipes - was high, but was not quantified. After 1990 it declined rapidly with a characteristic succession pattern: Eichhornia ® Vincularia + Cyperaceae ® Salvinia. The Cyperaceae, and many other less dominant species, were mostly associated with drift wood, produced by the decomposing, emergent forest. Comparison of the chemical data of the Uatumã river before the construction of the dam (1983) with those of later years (1989 - 1995) suggests that the succession was the result of a relatively mild and short period of eutrophication, followed by declining nutrient levels. Annual variation of water levels, followed by aquatic and terrestrial decomposition of the marginal vegetation, may allow for the maintenance of relatively productive vegetation belts along the shore lines of islands and inundated stream valleys.

scholarly journals The effect of the Danube diversion on the soil moisture conditions in Csallóköz and Szigetköz

2021 ◽  
pp. 1-8
Keyword(s):  
Time Series ◽  
Soil Moisture ◽  
Monitoring Program ◽  
Hydroelectric Power Plant ◽  
Water Levels ◽  
Hydroelectric Power ◽  
Groundwater Levels ◽  
Rooting Zone ◽  
Soil Moisture Storage ◽  
Moisture Conditions

Summary. Following the commissioning of the Gabčíkovo (Bős) hydroelectric power plant in 1992, a monitoring program was launched to assess the agricultural and forestry consequences of the diversion of the Danube into a newly built derivation channel in the Žitný ostrov (Csallóköz) and Szigetköz areas. Prior to the Danube diversion, groundwater played a significant role in the water supply of plants, therefore it is of primary importance to monitor the changes in groundwater levels and soil moisture. Correlation between the groundwater depth and soil moisture time series taken at four measurement points of Szigetköz (T-03, T-04, T-09, T-16) between 1995 and 2012 was analysed. Average and extreme water levels (quartiles 1 and 4) were examined for the 18-year time series, in which 2nd and 3rd quartiles of the groundwater levels were treated together as characteristic water level. It was found that groundwater significantly correlated with soil moisture storage below the rooting zone of field crops. Összefoglalás. A Gabčíkovo (Bős) vízerőművet 1992-ben helyezték üzembe. A dunacsúnyi duzzasztó vize a bősi erőművön átfolyva a Szlovákiában épített vízlevezető csatornából 40 km után tért vissza a korábbi Duna főmederbe. A régi Duna főmederbe emiatt az elterelt szakaszon a korábbi vízmennyiség ötöde került. Minthogy mind a szlovákiai, mind a magyarországi mezőgazdasági és erdőterületek vízellátásában a talajvíz és a dunai árhullámok jelentős szerepet játszottak, 1995-től a Duna-elterelés hatásának felmérésére talajvízszint és talajnedvesség monitoring program indult a Csallóközben és a Szigetközben. A szlovák megfigyelések publikált anyagainak megállapításait és a Szigetközből két szántóföld, egy kaszálórét és egy nyárfaültetvény 1995 és 2012 közötti mérési adatait dolgoztuk fel. A talajvízmélység és a 10 cm-es talajrétegek mért térfogatszázalékos (v.%) nedvességtartalmából számított talajvízkészletek közötti korrelációt számítottuk. A 18 éves idősoron külön vizsgáltuk a jellemző, illetve a szélsőséges vízszintek (1. és 4. kvartilisek) hatását. A jellemző vízszintek hatásának vizsgálatához a talajvízszint értékek 2. és 3. kvartilisét egyben kezeltük. Megállapítottuk, hogy szignifikáns, ill. közel szignifikáns összefüggés csupán az átlagosnál a talajfelszínhez közelebbi (Q1) talajvízmélység esetén volt kimutatható mind a mély (T-03), mind a sekély talajrétegű (T-09) szántóföld 210–300 cm-es, illetve 120–140 cm-es talajszintjében. Vagyis a szántóföldi kultúrák számára az átlagos talajvízmélység nem jelentett vízpótlást. A régi Duna főmederhez közeli kaszálóréten (T-04) a talajvízmélység helyett a dunaremetei medervízszint adatok és a talajnedvességkészlet között még a 140 cm-es mélységben található kavicsos alapkőzet fölötti 20 cm-es talajrétegben sem volt jelentős kapcsolat. A mély talajrétegű (300 cm) erdészeti mérőhely (T-16) talajvízmélység és talajnedvességkészlet korrelációja csupán a 210–300 cm-es talajréteg esetében volt közel szignifikáns. A nyárültetvények fejlődéséhez szükséges éves 700–900 mm vízigény biztosítására emiatt a régi Duna főmederbe engedett többletvízre lenne szükség. A szántóföldi kultúrák terméshozama is elsősorban az adott év csapadékmennyisége és eloszlása szerint alakul. Amennyiben az időjárási feltételek kedvezőtlenek, megoldásként öntözni szükséges. Beszámoltunk továbbá arról, hogy két éve négy mérőhely üzemel, ami a naponta óránként mért 6 órás átlag talajnedvesség-adatokat gyűjti. A folyamatos talajnedvesség-adatgyűjtés célja az időjárás, a növényi vízfelhasználás és a talajvízből történő nedvesítés nyomon követése és a talajvízforgalom-modell leírásának a kontrollja. A közeljövő feladata az évente 12-14 alkalommal az ezeken a mérőhelyeken is gyűjtött kapacitívszondás és a folyamatos nedvességmérési eredmények megfeleltetése, minthogy a bemutatott közel azonos példa mellett több helyen és mélységben időben párhuzamos módon változik ugyan a kétféle érték, azonban akár több, mint 5 v.% különbséggel.

scholarly journals The results of dipole sounding of the right bank of the dam of the Chirkei hydroelectric power plant

2019 ◽  
Vol 12 (2) ◽  
pp. 113-119
Author(s):  
Sh. G. Idarmachev ◽  
Ib. S. Idarmachev
Keyword(s):  
Rock Mass ◽  
Power Plant ◽  
Power Plants ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Geological Processes ◽  
Accuracy Of Measurements ◽  
Short Period ◽  
Geodynamic Processes ◽  
The Right

For the first time in the practice of full-scale studies in the area of the Chirkei HPP dam, the method of dipole electric sounding was used. The aim was to study the geodynamic processes in the rock mass located in the sides of the highrise dam to develop new methods of control of natural and man-made hazardous geological processes. The basis for the study of deformation processes in a large volume of the right bank of the dam was laid by the results of electric sounding of rocks by a small four-electrode in-well installation over the period 2010–2015, which showed that the change in the level of the reservoir caused seasonal deformation of rocks. The use of dipole sounding can significantly increase the size of the object under study. The volume of the probed rocks of the right bank of the dam is 6×106 m3, that is 2000 times larger compared to the four-electrode in-well installation. The equipment used is characterized by the continuity and high accuracy of measurements of apparent resistance of the mass, which enables to register the dynamic processes occurring in it. The results of observations by the method of dipole sounding over a short period of 2018 enable to conclude about the anthropogenic impact of the Chirkei hydroelectric power plant on the stress-strain state of rocks adjacent to the right side of the dam. For individual periods of observation, variations of apparent resistivity of large amplitude are detected, suggesting that the analyzed mass is in conditions of unstable equilibrium, i. e. displacements occur from time to time along the cracks in place. The movements can be triggered by starts of hydraulic units. Shifts in large tectonic cracks in the rock mass near the right side of the dam can lead to landslide processes and opening of cracks in the dam contact zone. The method of continuous dipole electric sounding can find its practical application for monitoring of hazardous geological processes in hydroelectric power plants.

scholarly journals Oxygen uptake from aquatic macrophyte decomposition from Piraju Reservoir (Piraju, SP, Brazil)

2011 ◽  
Vol 71 (1) ◽  
pp. 27-35 ◽  
Author(s):  
I. Bianchini Jr. ◽  
MB. Cunha-Santino ◽  
RS. Panhota
Keyword(s):  
Oxygen Consumption ◽  
Rate Constants ◽  
Aquatic Macrophyte ◽  
Oxygen Demand ◽  
Hydroelectric Power Plant ◽  
Order Kinetic ◽  
Hydroelectric Power ◽  
Myriophyllum Aquaticum ◽  
Reservoir Water ◽  
Eichhornia Azurea

The kinetics of oxygen consumption related to mineralisation of 18 taxa of aquatic macrophytes (Cyperus sp, Azolla caroliniana, Echinodorus macrophyllus, Eichhornia azurea, Eichhornia crassipes, Eleocharis sp1, Eleocharis sp2, Hetereanthera multiflora, Hydrocotyle raniculoides, Ludwigia sp, Myriophyllum aquaticum, Nymphaea elegans, Oxycaryum cubense, Ricciocarpus natans, Rynchospora corymbosa, Salvinia auriculata, Typha domingensis and Utricularia foliosa) from the reservoir of Piraju Hydroelectric Power Plant (São Paulo state, Brazil) were described. For each species, two incubations were prepared with ca. 300.0 mg of plant (DW) and 1.0 L of reservoir water sample. The incubations were maintained in the dark and at 20 ºC. Periodically the dissolved oxygen (DO) concentrations were measured; the accumulated DO values were fitted to 1st order kinetic model and the results showed that: i) high oxygen consumption was observed for Ludwigia sp (533 mg g-1 DW), while the lowest was registered for Eleocharis sp1 (205 mg g-1 DW) mineralisation; ii) the higher deoxygenation rate constants were verified in the mineralisation of A. caroliniana (0.052 day-1), H. raniculoides (0.050 day-1) and U. foliosa (0.049 day-1). The oxygen consumption rate constants of Ludwigia sp and Eleocharis sp2 mineralisation (0.027 day-1) were the lowest. The half-time of oxygen consumption varied from 9 to 26 days. In the short term, the detritus of E. macrophyllus, H. raniculoides, Ludwigia sp, N. elegans and U. foliosa were the critical resources to the reservoir oxygen demand; while in the long term, A. caroliniana, H. multiflora and T. domingensis were the resources that can potentially contribute to the benthic oxygen demand of this reservoir.

Water Level Control of Small-scale Hydroelectric Power Plant

2002 ◽  
Vol 122 (6) ◽  
pp. 989-994
Author(s):  
Shinichiro Endo ◽  
Masami Konishi ◽  
Hirosuke Imabayashi ◽  
Hayami Sugiyama
Keyword(s):  
Power Plant ◽  
Water Level ◽  
Hydroelectric Power Plant ◽  
Small Scale ◽  
Hydroelectric Power ◽  
Level Control

scholarly journals Spatial distribution of water level impact to back-barrier bays

2018 ◽  
Author(s):  
Alfredo L. Aretxabaleta ◽  
Neil K. Ganju ◽  
Zafer Defne ◽  
Richard P. Signell
Keyword(s):  
Water Level ◽  
Sea Level ◽  
Water Levels ◽  
Analytical Models ◽  
Barnegat Bay ◽  
Sea Level Fluctuations ◽  
Flooding Hazard ◽  
Short Period ◽  
Inlet Geometry ◽  
Spatial Estimates

Abstract. Water level in semi-enclosed bays, landward of barrier islands, is mainly driven by offshore sea level fluctuations that are modulated by bay geometry and bathymetry, causing spatial variability in the ensuing response (transfer). Local wind setup can have a secondary role that depends on wind speed, fetch, and relative orientation of the wind direction and the bay. Inlet geometry and bathymetry primarily regulate the magnitude of the transfer between open ocean and bay. Tides and short-period offshore oscillations are more damped in the bays than longer-lasting offshore fluctuations, such as storm surge and sea level rise. We compare observed and modeled water levels at stations in a mid-Atlantic bay (Barnegat Bay) with offshore water level proxies. Observed water levels in Barnegat Bay are compared and combined with model results from the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system to evaluate the spatial structure of the water level transfer. Analytical models based on the dimensional characteristics of the bay are used to combine the observed data and the numerical model results in a physically consistent approach. Model water level transfers match observed values at locations inside the Bay in the storm frequency band (transfers ranging from 70–100 %) and tidal frequencies (10–55 %). The contribution of frequency-dependent local setup caused by wind acting along the bay is also considered. The approach provides transfer estimates for locations inside the Bay where observations were not available resulting in a complete spatial characterization. The approach allows for the study of the Bay response to alternative forcing scenarios (landscape changes, future storms, and rising sea level). Detailed spatial estimates of water level transfer can inform decisions on inlet management and contribute to the assessment of current and future flooding hazard in back-barrier bays and along mainland shorelines.

Hydroelectric Power-Plant Simulator Implemented in Python

2021 ◽  
Author(s):  
Michal Kuchar ◽  
Adam Peichl ◽  
Milan Kucera ◽  
Jaromir Fiser ◽  
Pavel Kulik ◽  
...  
Keyword(s):  
Power Plant ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power

scholarly journals Dynamics of Lady’s slipper orchid (Cypripedium calceolus L.) population at Lake Kwiecko (West Pomerania)

2014 ◽  
Vol 36 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Maciej Korczyński ◽  
Ewa Krasicka-Korczyńska
Keyword(s):  
Power Plant ◽  
Endangered Species ◽  
Rare Species ◽  
Negative Impact ◽  
Good Condition ◽  
Hydroelectric Power Plant ◽  
Field Observations ◽  
Hydroelectric Power ◽  
Cypripedium Calceolus ◽  
Slipper Orchid

Abstract Cypripedium calceolus is considered an endangered species in the territory of Poland. Population of this rare species, situated at Lake Kwiecko (Western Pomerania), was regularly monitored in the years 1986-2013. The studied population has been under the permanent influence of the nearby hydroelectric power plant for almost 45 years. The field observations showed that the power plant had no negative impact on the condition of Cypripedium calceolus population. An indication of its good condition was, among others, an increase in the size - from 150 to 350 specimens within the study period.

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