Hydrodynamics and Water Quality Aspects of Goleşti, Romania, Reservoir (original) (raw)

Hydrodynamics and Water Quality Aspects of Goleşti Reservoir in Romania

2014

Many aquatic ecosystems have become more eutrophic at the present. In this context, several models have been already developed for simulate the behavior of eutrophic ecosystems which involve hydrodynamics, food chain and nutrient cycles. Most of the reservoirs have a complex use allowing the flood attenuation, generation of hydroelectricity, household and industrial water supply, and irrigation. Stratification and water movement in those reservoirs is affected by variability in heat fluxes through the lake surface, in addition to chemical and biological processes. The resulting internal hydrodynamics is important in understanding the lake’s physical, chemical, and biological structure. This paper presents a hydrodynamic model which reproduces water movement in lakes caused by solar radiation and wind kinetic energy. Also, the lake stratification and thermocline variation (temperature gradient and depth) will be studied, correlated with exploitation conditions. The model was calibrat...

A Mathematical Model of a Shallow and Eutrophic Lake (Stiucii – Romania)

Energy Procedia, 2017

The existence of lakes with eutrophication problems(54% in Romania) demands a predictive tool for the quality of these ecosystems. This paper proposes an eutrophication model that describes the ecological behavior of a eutrophic closed ecosystem. This model was used to study the shallow lake-Stiucii located in Cluj area-Romania. The conceptual model analyzes a simply food web (nutrients, primary producers and secondary consumers), and reproduces the spatial and temporal concentration of water quality constituents. The results provided by the model show a good correlation with the recorded values of the studied parameters. The RMSE values for the total nitrogen, zooplankton biomass and ammonia obtained are: 0.2 for zooplankton, 0.21 for ammonia and 0.35 for total nitrogen.

The Eutrophication Phenomenon in Gole Ti Lake-Romania

2011

Eutrophication on worldwide scale, as an effect of the anthropic impact, is one of the most serious problems that affect the quality of the water. Existence of a large percentage of lakes with eutrophication problems, demands a predictive tool for the quality of these ecosystems. This study present the qualitative analysis of such an ecosystem, based on ecological modelling. This paper proposes an ecological model (nutrient-phytoplankton) that describes the biochemical behaviour of a eutrophic reservoir. The 1D model developed allows the estimation of nutrients concentration and algae biomass and nutrient limited evidence on algal growth rate. The model was calibrated and validated with data from 2008 and 2009 in Gole ti Lake. The model reproduces spatial and temporal concentration distribution of water quality constituents.

Numerical modeling of thermal stratification in a lake reservoir. Methodology and case study

Aquatic Sciences, 2000

A numerical model of the hydrodynamic and thermal structure of an artificial lake was designed and developed as a basis for an ecological water-quality model. It allows the quantification of the vertical mixing processes that govern not only the thermal structure but also the nutrient exchanges, and more generally the distribution of dissolved and particulate matter between the different parts of the lake. The vertical temperature profiles were calculated by solving the onedimensional heat transfer equation that takes into account the internal heat sources and sinks, advection due to inflow and outflow and the molecular and eddy diffusions. A finite-difference discretization of first-order in time and second-order in space was chosen. The numerical time-step was three hours and layers were one-meter in thickness. These time-and space-scales are wellsuited to perform a precise simulation of the different processes occurring over a seasonal period. Moreover, this simulation requires only a reasonable amount of computer time.

The Eutrophication Model and Its Application to Roşu Lake–Romania

wseas.us

Abstract: - The study of water quality in natural or artificial reservoirs is important in controlling the eutrophication phenomenon. Many lakes in Romania are eutrophic and dominated by algae blooms. The present ecological situation reflects the result of nutrient loading combination ...

Contribution of mathematical modeling to lake ecosystem understanding: Lake Bourget (Savoy, France

Hydrobiologia, 1995

This paper demonstrates how mathematical modeling can contribute to improve understanding of lake behavior. Since the 60's Lake Bourget, one of the largest in France, had been suffering from eutrophication which was checked in 1980 by the diversion of the main sewers entering the lake. A research program was implemented between 1987 and 1990, including an on-site sampling campaign conducted concurrently with thermal and biogeochemical modeling of lake behavior. The model helped provide a better understanding of the ecosystem, displaying some processes hitherto misunderstood: (1) Winter overturn does not reach the bottom of the water column when the weather is mild. This leads to a incomplete reoxygenation of the hypolimnion and to redox conditions inducing the release of orthophosphate from the sediment, (2) Grazing by herbivorous zooplankton is getting more important in the control of spring algal growth as eutrophication of the lake regresses, (3) Settling of particulate phosp...

Thermodynamic modeling in solving some issues of inland saline ecosystems

E3S Web of Conferences, 2019

The purpose of this work was to show some examples of using thermodynamic modeling to understand quantitatively the water-rock interaction processes in salt lakes systems. The systems of small lakes located compactly are convenient to comparative modeling, because this permits minimization of the number of variables in the model (the climatic, geomorphological and geological specifics, water balance in the same watershed area). Nevertheless, it turns out that each lake is a relatively autonomous system (natural biogeocenosis, formed as a result of diagenesis). Due to the conjugate processes of biogenic and inorganic interactions, they are in a steady state, which has been fixed during the geochemical sampling in the field.

Simulation of water temperature and dissolved oxygen distribution in Lake Vegoritis, Greece

Ecological modelling, 2003

Changes in lake water temperature and temperature stratification dynamics can have a profound effect on lake biological and chemical processes. A one-dimensional temperature stratification and oxygen prediction model was developed to simulate the seasonal temperature cycle and oxygen distribution for Lake Vegoritis in Northern Greece. The submodel of heat transport is based on the non-linear heat transfer equation using daily weather parameters as input data. The dissolved oxygen (D.O.) submodel is based on the unsteady diffusion equation with the oxygen fluxes through the free surface and bottom of lake as boundary conditions, and photosynthetic oxygen production, biochemical oxygen demand and plant respiration as internal sources and sinks. The solution of these equations uses the finite element method. The model was calibrated and verified by using data from Lake Vegoritis from two different years (1981 and 1993). The model results showed that there was good agreement between the simulated and the measured values of water temperature and D.O. at different depths in the lake and on different days of the year. #

Analysis and Modelling of Temperature at Lake’s Water – Atmosphere Interface

The knowledge of micrometeorological conditions on water surface of impoundments is crucial for the better modeling of the temperature and water quality parameters distribution in the water body and against the climatic changes. Water temperature distribution is an important factor that affects most physical, chemical and biological processes and reactions occurring in lakes. In this work, different processes of water surface temperature of lake’s estimation based on the energy balance method are considered. The daily meteorological data and the simulation results of energy balance components from an integrated heat transfer model for two complete years as well as the lake’s characteristics for Vegoritis lake in northern Greece were used is this analysis.The simulation results of energy balance components from a heat transfer model are considered as the reference and more accurate procedure to estimate water surface temperature. These results are used to compare the other processes....