Nitrogen and phosphorus concentration of different structures of the aquatic macrophytes Eichhornia azurea Kunth and Scirpus cubensis Poepp & Kunth in relation to water level variation in Lagoa Infernão (São Paulo, Brazil)

Hydrobiologia ◽  
1996 ◽  
Vol 328 (3) ◽  
pp. 199-205 ◽  
Author(s):  
Flávia Nogueira ◽  
Francisco de Assis Esteves ◽  
Alex Enrich Prast
Keyword(s):  
Water Level ◽  
Aquatic Macrophytes ◽  
Sao Paulo ◽  
Phosphorus Concentration ◽  
São Paulo ◽  
Level Variation ◽  
Nitrogen And Phosphorus ◽  
Water Level Variation ◽  
Eichhornia Azurea

scholarly journals Analysis of the Water Level Variation in the Polish Part of the Vistula Lagoon (Baltic Sea) and Estimation of Water Inflow and Outflow Transport through the Strait of Baltiysk in the Years 2008–2017

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1328
Author(s):  
Michał Szydłowski ◽  
Wojciech Artichowicz ◽  
Piotr Zima
Keyword(s):  
Statistical Analysis ◽  
Numerical Model ◽  
Baltic Sea ◽  
Water Level ◽  
Vistula Lagoon ◽  
Level Variation ◽  
The Baltic Sea ◽  
Water Level Variation ◽  
The Baltic ◽  
The Vistula Lagoon

The Vistula Lagoon is located in both Poland and Russia along the southern coast of the Baltic Sea. It is connected to the Baltic Sea in the Russian part by the Strait of Baltiysk. The purpose of the paper is to identify the dominant factors underlying the water level variation mechanism at Tolkmicko in the Vistula Lagoon, revealed by a statistical analysis of the measured data and a discussion on the inflow and outflow transport variation through the strait, estimated by numerical modeling. Seawater transport is exceptionally valuable in terms of the hydrological water balance in the lagoon. Historical research on the hydrology of the lagoon shows that the water exchange in the lagoon is quite complex due to the presence of several different sources of water balance, such as seawater inflow, river inflow, groundwater inflow, precipitation, and evaporation. Unfortunately, there are no current data on seawater inflow and outflow through the Strait of Baltiysk due to the lack of continuous flow measurements in the strait. A novelty of the current work is an in-depth statistical analysis of the water level variation in the Polish part of the lagoon over a long time period and an estimation of water transport through the Strait of Baltiysk by use of a numerical model. The model reproduces well the water level variation responding to variations in the sea level outside the lagoon and the wind action over the lagoon. The years 2008–2017 were chosen as the analysis period. A two-dimensional free surface shallow water numerical model of the lagoon was adapted to simulate the water level variation in view of the wind over the lagoon and the sea level variation at one open boundary. Finally, it was concluded that the water level variation on the Polish side of the Vistula Lagoon is dominated by two factors: the water level in the Gulf of Gdańsk and the wind over the lagoon. The average annual marine water inflow into the Vistula Lagoon was estimated to be equal to 15.87 km3.

scholarly journals Induced reproduction in a migratory teleost species by water level drawdown

2015 ◽  
Vol 13 (1) ◽  
pp. 205-212 ◽  
Author(s):  
Chayrra Chehade ◽  
Mônica Cassel ◽  
Maria Inês Borella
Keyword(s):  
Environmental Factors ◽  
Water Level ◽  
Gonadosomatic Index ◽  
Hormonal Treatment ◽  
Fish Farming ◽  
Sao Paulo ◽  
Morphological Description ◽  
Advanced Stage ◽  
São Paulo ◽  
Sample Period

Captive reproduction is one of the problems faced in aquaculture requiring the manipulation of environmental factors and/or hormonal treatment. Thus, we seek to verify experimentally which gonadal changes were present in mature individuals of Astyanax altiparanae arising from decreased water level. Collections were made every four hours, initiated four hours before and finished 28 hours after stimulation, at the Fish Farming Station of Companhia Energética de São Paulo, São Paulo, Brazil. The gonads were analyzed by light microscopy. The females had ovaries in the spawning capable phase until 12h; in 16h, in a more advanced stage of spawning capable phase; and, from 20h, in the regressing phase. Males had testes in the spawning capable phase until 8h; in 12h, in a more advanced stage of spawning capable phase; and, from 16h, the return to the spawning capable phase. The morphological description was corroborated by the proportion of cell classes. Females presented variation on the gonadosomatic index, but it was not found an emptying of the gonad for neither sex. The process of inducing reproduction with water level drawdown was considered satisfactory, since both sexes presented a reduction in the number of mature gametes at the end of the sample period.

Integrated factor analysis of water level variation in geographically isolated ponds

2020 ◽  
Vol 27 (31) ◽  
pp. 38861-38870
Author(s):  
Yufeng Li ◽  
Yuqin Wu ◽  
Alan Wright ◽  
Jiayi Xu ◽  
Hongyu Liu ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Water Level ◽  
Level Variation ◽  
Water Level Variation ◽  
Geographically Isolated

scholarly journals Study of Water Level Variation in the Reservoir at the Ilha Solteira Dam (Brazil) Based on Geodesic Remote Sensing

2019 ◽  
Vol 42 (1) ◽  
pp. 490-495
Author(s):  
J. R. S. OLIVEIRA ◽  
J. MARCATO ◽  
F. S. PROL ◽  
R. MACHADO ◽  
F. B. DALMAS ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Level ◽  
Level Variation ◽  
Water Level Variation

scholarly journals Nitrogen and phosphorus in cascade multi-system tropical reservoirs: water and sediment

2017 ◽  
Vol 17 (3) ◽  
pp. 133-150 ◽  
Author(s):  
Marcelo Pompêo ◽  
Viviane Moschini-Carlos ◽  
Julio Cesar López-Doval ◽  
Natália Abdalla-Martins ◽  
Sheila Cardoso-Silva ◽  
...  
Keyword(s):  
Sediment Quality ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Sao Paulo ◽  
São Paulo ◽  
Nitrogen And Phosphorus ◽  
Paulo State ◽  
Tropical Reservoirs ◽  
Water And Sediment ◽  
Main Compartment

AbstractThe aim of this research was to analyze the horizontal spatial heterogeneity of both water and superficial sediment quality among and within the reservoirs of the Cantareira System (CS), focusing on concentrations of N and P, attributed to the dumping of raw domestic sewage into water bodies, which is the main cause of water pollution in São Paulo State (Brazil). The CS is a multi-system complex composed of five interconnected reservoirs, with water transported by gravity through 48 km of tunnels and channels. From the last reservoir of the CS, with an output of 33 m3s−1, the water is conducted to a water treatment plant, producing half of the water consumed by 19 million people inhabiting São Paulo city. The upstream reservoirs are more eutrophic than the downstream ones. Data also suggest that the low phytoplankton biomass (ranging from 0.9 to 14.4 μg dm−3) is regulated by the low nutrient availability, mainly of phosphorus (TP ranging from below the detection limit, <9.0 μg dm−3, to 47.3 μg dm−3). For water, the DIN/TP ratios values range from 19 to 380. The upstream reservoirs function as nutrient accumulators and the sediment is the main compartment in which P and N are stored. Although the reservoirs are located in different river basins and are not in sequence along the same river, the results suggest a marked gradient between the reservoirs, with features similar to those of cascade reservoirs. The large volumes flowing through the canals and tunnels could explain the observed pattern. The CS reservoirs can therefore be considered multi-system reservoirs in cascade, constituting a particular case of multi-system reservoirs.

scholarly journals Reproductive seasonality of fishes from a lotic stretch of the Grande River, high Paraná river basin, Brazil

2005 ◽  
Vol 65 (3) ◽  
pp. 387-394 ◽  
Author(s):  
P. M. Andrade ◽  
F. M. S. Braga
Keyword(s):  
Water Level ◽  
Air Temperature ◽  
Relative Frequency ◽  
Reproductive Activity ◽  
Seasonal Reproduction ◽  
Level Variation ◽  
Reproductive Seasonality ◽  
Water Level Variation ◽  
Dam Operation ◽  
Fish Gonads

We searched for correlations between water level, rainfall, temperature, and reproductive activity of fishes in a lotic stretch of the Grande River below the Volta Grande Dam. Gillnets were used to catch the fish on six field journeys made bimonthly between April 1998 and February 1999. Fish gonads were classified according to maturation grade and the amount of mature or spent gonads was correlated with rainfall and air temperature. Most fish species showed seasonal reproduction (between October and February). The relative frequency of fully mature and spent gonads significantly correlated with rainfall (Spearman r = 0.94, p = 0.005) and air temperature (r = 0.84, p = 0.036), showing the importance of these factors in regulating the reproductive cycle of fishes in this location. Nevertheless, dam operation resulted in minimal water level variation that did not significantly correlate with reproductive activity (r = -0.43, p = 0.396).

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