Modelación numérica de la hidrodinámica, del oxígeno disuelto y la demanda bioquímica de oxígeno en sistemas con vegetación

This work deals with the implementation of a numerical model to simulate hydrodynamics and transport of pollutants in flows where submerged vegetation is present. The model is based on the Shallow-Water Equations to calculate the mean velocities, emphasizing calculations of the shear stress produced by both the vegetation and turbulence. The Advection-Diffusion-Reaction Equation is used to calculate the transport of the Biochemical Oxygen Demand and the Dissolved Oxygen. The main objective is to simulate the transport of these substances and the pollution filtering and reaereation functions of plants in water bodies such as wetlands. In the obtained velocity fields, the change of the behavior due to the restriction imposed by the vegetation can be seen. The BOD and DO concentrations are influenced by the residence time and the reaereation from the atmospheric exchange and plants breathing. As a conclusion, the model represents very precisely the behavior of dissolved substances transport in flows with presence of vegetation and can be applied to different ecosystems, being capable to predict the path and fate of pollution.El presente trabajo trata sobre la implementación de un modelo numérico para simular la hidrodinámica y el transporte de contaminantes en sistemas donde existe vegetación, tanto sumergida como emergente. Dicho modelo se basa en las ecuaciones de aguas someras para el cálculo de las velocidades del flujo, haciendo énfasis en la evaluación del esfuerzo cortante de arrastre de las plantas y en la turbulencia; así como en la ecuación de advección-difusión-reacción para la simulación del transporte de sustancias disueltas. En este trabajo se presenta el cálculo del transporte de la Demanda Bioquímica de Oxígeno y del Oxígeno Disuelto. El objetivo principal es reproducir las funciones de filtrado de contaminación y reaereación que cumplen las plantas en cuerpos de agua, como los humedales. En los resultados obtenidos del campo de velocidades se aprecia el cambio de comportamiento por la restricción al flujo que impone la vegetación. Las concentraciones de DBO y OD varían debido al tiempo de residencia y a la reaereación producida por el intercambio atmosférico y la respiración de las plantas. Se concluye que el modelo representa de manera óptima el comportamiento del transporte de sustancias disueltas en flujos con presencia de vegetación y que se puede aplicar a la gran variedad de ecosistemas, siendo capaz de predecir la ruta y destino de la contaminació

A Case Study of Nearshore Wave Transformation Processes along the Coast of Mexico near the Laguna Verde Nuclear Power Plant Using a Fast Simulation Method

A numerical model based on the mild-slope equation of water wave propagation over complicated bathymetry, taking into account the combined effects of refraction, diffraction, and reflection due to breakwater, is presented. The numerical method was developed using a split proposed version of the mild-slope equation and solved by an implicit method in a finite volume grid; this technique easily allows model the wave effects caused by the breakwater building in coastal waters, where industrial and other economic activities take place. Controlled case studies have been made and the results match very well with the reference solution. The capability and utility of the model for real coastal areas are illustrated by application to the breakwater of the Laguna Verde Nuclear Power Plant (LVNPP)

Numerical modelling of the laguna verde nuclear power station thermal plume discharge to the sea

The coastal water pollution is a problem that responds to the overpopulation, natural resources exploitation and the increase of technologic development; this has led to an alteration of the physical, chemical and biological parameters of both continental and coastal waters. Among the main sources of pollution are those arising from industrial activities, this is the case of the electricity generation industry which requires large volumes of water for cooling systems. This work contributes to the knowledge of the behaviour of thermal discharges into coastal waters, and it requires solving the Navier-Stokes-Reynolds equations for shallow waters, using a numerical model formerly developed; water quality equations associated are solved too. The results obtained are satisfactory, since dispersion patterns of the thermal plume are well reproduced in accordance with the patterns measured for different climate scenarios in the zone

Hydrodynamic modeling for the sustainable management of the guájaro hydrosystem, Colombia

The Guájaro reservoir is the most important water body located at the north of Colombia. It is supplied by an artificial channel (Canal del Dique) through a two floodgates system. As a result of excess nutrients and other pollution loads from the drainage basin in recent decades, the Guájaro reservoir suffers eutrophication and other pollution problems; however it still continues being exploited. For this reason, it is necessary to regulate the hydraulic structures that supply this water body, as they play an important role in managing levels, and these in turn for water supply and environmental purposes. The present work is carried out as a sustainability management alternative of the reservoir. The implementation of a two-dimensional hydrodynamic model and its calibration is achieved using time series of the free surface levels, and comparing the measured velocities and those estimated by the model for two different climatic periods, to assist the operation of the Canal del Dique-Guájaro hydrosystem. The corresponding comparisons showed a good behavior between measured and simulated data. Based on the quantitative results of the Nash-Sutcliffe reliability method, the results are considered quite satisfactory for estimating and predicting the amount of water flowing in and out of the reservoir through the channel reservoir hydrosystem

Hydrodynamic modeling for the water management of the Guájaro reservoir, Colombia

El embalse del Guájaro, en el norte de Colombia, es un sistema hídrico abastecido por un canal artificial (el canal del Dique) a través de un dispositivo de compuertas. Durante las últimas décadas, ha presentado problemas de aprovechamiento excesivo, por lo cual resulta necesario regular las estructuras hidráulicas que abastecen este cuerpo de agua, ya que desempenan ˜ un papel importante en el manejo de los niveles, los cuales, a su vez, repercuten en la oferta hídrica. Como medida de gestión para la sostenibilidad del embalse se ha desarrollado este trabajo, en que se presenta la implementación de un modelo hidrodinámico bidimensional (modelo EFDC Explorer), así como su calibración mediante la comparación de series temporales de los niveles de agua del embalse con los resultados de las velocidades medidas y las calculadas por el modelo, durante 2 períodos climáticos distintos (secas y lluvias), para contribuir con una herramienta computacional a la explotación sostenible del Hidrosistema Canal del Dique-Embalse El Guájaro. Las comparaciones realizadas mostraron un buen comportamiento y un buen ajuste entre los valores medidos y los simulados por el modelo, basados en los resultados cuantitativos de fiabilidad (Nash-Sutcliffe). Se considera que los resultados obtenidos son bastante satisfactorios y permiten estimar condiciones para la restauración, el aprovechamiento y el uso sostenible de este sistema hídricoThe reservoir of Guájaro, in northern Colombia, is a water system supplied by an artificial channel (the Canal del Dique) through a gate device. During the last decades, it has presented problems of excessive use, for which it is necessary to regulate the hydraulic structures that supply this body of water, since they play an important role in the management of the levels, which, in turn, have an impact in the water supply. As a management measure for the sustainability of the reservoir, this work has been developed, in which the implementation of a two-dimensional hydrodynamic model (EFDC Explorer model) is presented, as well as its calibration by comparing time series of the water levels of the reservoir with the results of the measured speeds and those calculated by the model, during 2 different climatic periods (dry and rainy), to contribute with a computational tool to the sustainable exploitation of the Hidrosistema Canal del Dique-El Guájaro Reservoir. The comparisons made showed a good behavior and a good fit between the measured values ​​and those simulated by the model, based on the quantitative reliability results (Nash-Sutcliffe). It is considered that the obtained results are quite satisfactory and allow to estimate conditions for the restoration, the aprovechamiento and the sustainable use of this hydric syste

Numerical modeling of hydrodynamics in the Agua Brava lagoon, located in Nayarit, Mexico

In this paper a study of the hydrodynamics of the Agua Brava lagoon system is performed by numerical modeling. The importance of studying this lagoon system lies with aquaculture activities carried out by shrimp farms. The π-HYDRO model is used for the numerical simulations of hydrodynamics and temperature and salinity dispersion. The boundary conditions regarding ocean properties were generated with the HYCOM ocean model, whereas tides were calculated from the tidal predictions of the MAR V1.0. A hydrological study was also performed to calculate the freshwater contributions and take them into account in the numerical simulations. The scenarios analyzed are the dry and wet seasons particularly for 2013. For the case of the dry season, a slight influence of hydrological contributions to the dynamics of the lagoon is observed, where the effects of the tidal flow are predominant. For the wet scenario, the effects of both tidal and hydrological flow drive the motion within the lagoon, especially being predominant the hydrological flow due to the river discharges in the near region to the shrimp farms

Hydraulic and environmental design of a constructed wetland as a treatment for shrimp aquaculture effluents

Shrimp aquaculture has grown to the extent that pressure on natural ecosystems has greatly increased. The shrimp farms effluents usually discharge their wastes, with high nutrients load, into coastal water bodies without any previous treatment. This work presents a method to design a constructed wetland for handling these effluents. Our method is based on a first order equation model and a hydrodynamic numerical model as the main component for the design process. Numerical results showed consistency with the first order theory, when pollutants concentration were reduced to values accepted by the applicable regulations

Validación de un modelo hidrodinámico y calidad del agua para el Río Magdalena, en el tramo adyacente a Barranquilla, Colombia

Water quality models are tools of control, that contribute to the planning, prevention and decision making focused on water resource management. Therefore, different countries, among which is Colombia, have established the relevance of its implementation to determine the discharges assimilation of water bodies. This is why this research aims to simulate the transport of pollutants from effluents of the industrial corridor of Barranquilla, to study the dispersion and contaminants fate to represent the pollution level in this ecosystem. To develop this work, a two-dimensional numerical model was adapted and implemented, which consists of two modules and is solved in two stages. Initially, the hydrodynamic module is applied to solve the Saint Venant equations derived from Navier-Stokes-Reynolds, using an Eulerian-Lagrangian method. After that, the contaminant transport module that solves the two-dimensional advection-diffusion-reaction equation is applied. With the simulation of rivers discharges, the evolution and behavior of pollutants discharged into it was described, which demonstrate the model capability to represent the water quality in receiving bodies with complex hydraulic and hydrodynamic conditions.Los modelos matemáticos de calidad del agua son una herramienta de control, que contribuyen a la planificación, la prevención y toma de decisiones enfocadas al manejo de los recursos hídricos. Por ello, diferentes países, entre los cuales está Colombia, han establecido la pertinencia de su implementación para determinar el grado de asimilación de los cuerpos de agua a vertimientos de diferente índole. Por lo cual, esta investigación tuvo como objetivo simular el transporte de los contaminantes provenientes de los efluentes del corredor industrial de Barranquilla, para realizar estudios de dispersión y destino de contaminantes que permitan representar el nivel de contaminación que se tiene en el ecosistema estudiado. Para el desarrollo de este trabajo se adaptó e implementó un modelo numérico bidimensional, que consta de dos módulos y se resuelve en dos tiempos. Inicialmente se aplicó el modulo hidrodinámico que resuelve las ecuaciones de Saint Venant derivadas de Navier-Stokes-Reynolds, mediante un método Euleriano-Lagrangeano. Posteriormente se aplicó el módulo de transporte de contaminantes que resuelve la ecuación de Advección-Difusión-Reacción en su forma bidimensional, también por el método Euleriano-Lagrangeano. A través de la simulación de los vertimientos descargados al río, se describió la evolución y comportamiento de los contaminantes descargados en éste, demostrando la capacidad del modelo implementado para representar la calidad del agua en este tipo de cuerpos receptores, con condiciones hidráulicas e hidrodinámicas complejas

The hydrodynamic modelling for the water management of el Guájaro Reservoir, Colombia

El embalse del Guájaro, en el norte de Colombia, es un sistema hídrico abastecido por un canal artificial (el canal del Dique) a través de un dispositivo de compuertas. Durante las últimas décadas, ha presentado problemas de aprovechamiento excesivo, por lo cual resulta necesario regular las estructuras hidráulicas que abastecen este cuerpo de agua, ya que desempenan ˜ un papel importante en el manejo de los niveles, los cuales, a su vez, repercuten en la oferta hídrica. Como medida de gestión para la sostenibilidad del embalse se ha desarrollado este trabajo, en que se presenta la implementación de un modelo hidrodinámico bidimensional (modelo EFDC Explorer), así como su calibración mediante la comparación de series temporales de los niveles de agua del embalse con los resultados de las velocidades medidas y las calculadas por el modelo, durante 2 períodos climáticos distintos (secas y lluvias), para contribuir con una herramienta computacional a la explotación sostenible del Hidrosistema Canal del Dique-Embalse El Guájaro. Las comparaciones realizadas mostraron un buen comportamiento y un buen ajuste entre los valores medidos y los simulados por el modelo, basados en los resultados cuantitativos de fiabilidad (Nash-Sutcliffe). Se considera que los resultados obtenidos son bastante satisfactorios y permiten estimar condiciones para la restauración, el aprovechamiento y el uso sostenible de este sistema hídricoThe Guájaro Reservoir in northern Colombia is a hydrosystem that is supplied by an artificial channel (Canal del Dique) through a system of floodgates. During the last decades, has been presenting problems of excessive use, which is why, it is necessary to regulate the hydraulic structures that serve this water body, as they play an important role in managing the levels that in turn affect the water supply. The present work is carried out as a sustainability management alternative of the reservoir. A two-dimensional hydrodynamic model (EFDC Explorer) and its calibration is implemented using time series of the free surface levels, and comparing the measured velocities and those estimated by the model for two different climatic periods, to assist the operation of the Hydrosystem Canal del Dique-Guájaro Reservoir sustainability. The corresponding comparisons showed a good behavior between measured and simulated data, based on the quantitative results of Nash-Sutcliffe reliability method. It is considered that the results are quite satisfactory and allows the estimation of conditions for restoration, its use, as well as the incoming and outgoing water through hydrosystem channel-reservoir

The hydrodynamic modelling for the water management of el Guájaro Reservoir, Colombia

El embalse del Guájaro, en el norte de Colombia, es un sistema hídrico abastecido por un canal artificial (el canal del Dique) a través de un dispositivo de compuertas. Durante las últimas décadas, ha presentado problemas de aprovechamiento excesivo, por lo cual resulta necesario regular las estructuras hidráulicas que abastecen este cuerpo de agua, ya que desempenan ˜ un papel importante en el manejo de los niveles, los cuales, a su vez, repercuten en la oferta hídrica. Como medida de gestión para la sostenibilidad del embalse se ha desarrollado este trabajo, en que se presenta la implementación de un modelo hidrodinámico bidimensional (modelo EFDC Explorer), así como su calibración mediante la comparación de series temporales de los niveles de agua del embalse con los resultados de las velocidades medidas y las calculadas por el modelo, durante 2 períodos climáticos distintos (secas y lluvias), para contribuir con una herramienta computacional a la explotación sostenible del Hidrosistema Canal del Dique-Embalse El Guájaro. Las comparaciones realizadas mostraron un buen comportamiento y un buen ajuste entre los valores medidos y los simulados por el modelo, basados en los resultados cuantitativos de fiabilidad (Nash-Sutcliffe). Se considera que los resultados obtenidos son bastante satisfactorios y permiten estimar condiciones para la restauración, el aprovechamiento y el uso sostenible de este sistema hídricoThe Guájaro Reservoir in northern Colombia is a hydrosystem that is supplied by an artificial channel (Canal del Dique) through a system of floodgates. During the last decades, has been presenting problems of excessive use, which is why, it is necessary to regulate the hydraulic structures that serve this water body, as they play an important role in managing the levels that in turn affect the water supply. The present work is carried out as a sustainability management alternative of the reservoir. A two-dimensional hydrodynamic model (EFDC Explorer) and its calibration is implemented using time series of the free surface levels, and comparing the measured velocities and those estimated by the model for two different climatic periods, to assist the operation of the Hydrosystem Canal del Dique-Guájaro Reservoir sustainability. The corresponding comparisons showed a good behavior between measured and simulated data, based on the quantitative results of Nash-Sutcliffe reliability method. It is considered that the results are quite satisfactory and allows the estimation of conditions for restoration, its use, as well as the incoming and outgoing water through hydrosystem channel-reservoir