RIBAGUA-Revista Iberoamericana del Agua最新文献

Many calibration works have been performed to support the validity of the smoothed particle hydrodynamics (SPH) method for studying turbulent-free surface flows. However, its high computational requirements made it difficult to use in real cases. The development of techniques for supercomputing graphics processing units (GPU) has changed this situation, and is allowing its use as a design tool.

CEDEX has developed a model based on this technology, SPHERIMENTAL, in order to support studies on physical modelling. This has enabled the model to be calibrated in order to study complex phenomena.

This paper shows the works done to check the hydrodynamics free surface flows in the Nagore dam morning glory spillway, describing both the previous calibration works and the results obtained.

A method to calculate the freshwater discharge in an estuary and the net exchange flow with the sea measuring the evolution of the water level in fixed monitoring stations is presented. It rises from the need to obtain reliable data of discharges under the particular morphological conditions that determine the hydrodynamic behaviour of the coastal plain Quequén Grande River estuary (Buenos Aires, Argentina), in which the tide behaves as a standing wave. The technique is calibrated with direct measurements of discharges performed with an acoustic Doppler current profiler in field studies during periods of poor and abundant rains. It is found that the exchange of water with the sea is proportional to the time derivative of the height of the free surface, and the fluvial discharge can be estimated from the height difference between monitoring stations. The results make it possible to quantify the river contribution during dry and wet seasons, and the flows generated by occasional and unusual tides. The method proposed is simple, does not require complex instruments to continuously measure velocity, and takes advantage of existing monitoring nets to provide the information of the estuarine flows in real time and of historic files to evaluate the changes produced in the past.

El objeto de este artículo es presentar una panorámica del excepcional desarrollo en materia de diques portuarios que ha tenido lugar en España desde finales del siglo xx, presentando algunos de los proyectos más importantes, como son los de los puertos de Gijón, Ferrol, Coruña, Algeciras, Cartagena y Barcelona. Asimismo se incluyen referencias a los ensayos en modelo físico realizados en el CEDEX para el diseño y la construcción de estos diques.

The aim of this paper is to provide an overview of the important port breakwaters development that has taken place in Spain from the end of the XX century, including the detail of the ports of: Gijón, Ferrol, Coruña, Algeciras, Cartagena and Barcelona. References are also made to physical models tests conducted at CEDEX for its design and construction.

Storm surge from tropical cyclones is the main cause of flood induced damage in tropical regions. Nevertheless, storm surge estimations are limited by the scarcity of measurements and historical information of tropical cyclones. This is particularly true in Mexico because data is very scarce. Thus, this research presents an alternative method for estimating storm surge values from tropical cyclones for different return periods, in areas with insufficient historical information. The selected framework consists on the implementation of hydrodynamic models to reproduce the mean sea level elevation induced by the presence of tropical cyclones on the coast. For this, we used synthetic events (120 events) generated in the Atlantic Ocean during the defined time period between 1980–2010 and limited to a 100 km circular region around the mouth of the Panuco River in Mexico (22.26°N, 97.78°W), together with historical events (25) occurring between 1951 and 2012. The wind fields of these events are used as forcing for a hydrodynamic model in order to define the maximum storm surge at the point of interest. The obtained information allows for a more reliable extreme value analysis to determine storm surge levels for different return periods. The results demonstrate the usefulness of this methodology for using synthetic events in combination with historical information, in order to increase the reliability of the design values in areas with limited data.

After more than 20 years implementing the “Recommendations for the management of dredged material in Spanish ports” 1994 and taking into account both technical and scientific advances as well as the entry into force of new legislation in the European and Spanish contexts, in the process of implementation of the Spanish Law 41/2010 on the Protection of the Marine Environment, the Interministerial Commission for Marine Strategies adopted in April 2014 the “Guidelines for the characterization of dredged material and their relocation within waters of the maritime-terrestrial public domain”. These Guidelines should be applied for all the projects developed in the Spanish harbours from them.

This article reviews the main contents of this new management framework for dredged material in Spain and emphasizes the main differences with the former framework used in Spain. In the conclusions section, it is highlighted the methodological improvements and the problems solved, according the authors opinion, regarding the previous framework used.

Current legislation on microbiological control of water for human consumption in our country, and in many others, does not include the search of human-pathogenic parasites or viruses. Even though water purification methods used for the removal of bacteria from water do also remove the great majority of parasitic forms, some of their resistance elements are not affected by chlorination treatments. Groundwater obtained from shallow wells in semi-rural areas may also constitute a risk since they are very susceptible to contamination.

The aim of this work was to quantify parasitic elements and viruses present in water for human consumption in the Province of Salta, in Argentina. For that, 60 L water samples were collected in six points located in the Province, including two sources of water: the distribution network and shallow wells. Samples were collected during dry and wet seasons. Ultrafiltration techniques were used to concentrate the water in pathogens. Optical microscopy using a Neubauer chamber for the quantification of parasite elements and real-time PCR for the quantitative detection of viruses were used.

We found a great variety of protozoa genera in both groundwater and in the distribution network. Only in groundwater samples we found helminths and in one of them also adenovirus. Results showed that there is little relation between the presence of bacterial indicators (established by legislation) and pathogens as parasites and viruses. Numerous water samples that are within the limits established by legislation (for which they would be considered acceptable as water for human consumption) had pathogenic parasites or viruses. This shows the urgent need to update the current legislation to include parasitic indicators that allow certifying that the water is safe for human consumption, therefore decreasing the risk of waterborne diseases.

This work deals with getting operating rules for a dam which take into account the Comisión Federal de Electricidad operator's requests, besides to find a balance between the restrictions imposed by Comisión Nacional del Agua, in order to guarantee on the one hand, the biggest benefits for hydropower generation and on the other hand the lowest spill and deficit scenarios to avoid damages in downstream sites. This problem can be solved by applying a mathematical optimization model using several methodologies for this purpose.

In this analysis operating rules were obtained and simulated, for the hydropower system “El Infiernillo” using a stochastic dynamic programming algorithm, this method has been applied since almost two decades in several important hydropower dam systems in Mexico. The objective function used was to maximize the generation benefits, imposing penalties in case of spill or deficit in the system and also adding penalties when an upper or lower guide curve could be overtopped on their limits, these guide curves help to reconcile the operator organizations by setting with an upper level the safe dam storage volume for management purposes in case of extremes hydrometeorogical events and with the lower limits a minimum hydropower generation can be guaranteed in the system. With the application of the algorithm in several occasions proposing different penalty values, optimum operating rules expressed as a data table were obtained. Such rules where simulated with the fortnight inflow historical volume to the Dam from years 1965 to 2013.

The extraction volume in the time interval chosen for the simulation can be decided in a simply way by the operator helped with an extraction values table according to the storage in the dam; besides is incorporated, during the simulation, the effect of the inflow volume autocorrelation by adding or subtracting a specified volume taking into account the inflow magnitude from the previous time interval, with respect to the mean historical inflow volume in the same previous time interval.

Se ha realizado una investigación mediante modelación física sobre diques en escollera rebasables con el objetivo de verificar la idoneidad del uso de los parámetros de altura de ola H_50t (altura promedio de las 50 mayores olas totales) y H_50i (altura promedio de las 50 mayores olas incidentes) en la formulación de los números de estabilidad que permiten diseñar la estructura. Adicionalmente, se ha introducido la dependencia del francobordo en estas formulaciones. Se han realizado ensayos experimentales sobre una estructura en escollera con un núcleo y un manto bicapa, para tres niveles de francobordo (emergido, a nivel del agua en reposo y sumergido), a escala 1:50. Se han comparado los valores del daño S medidos y calculados, considerando las estimaciones obtenidas en función de la altura de ola incidente H_50i y de la altura total H_50t. Se ha demostrado que, para la estructura utilizada en este trabajo, el mejor ajuste se obtiene utilizando la H_50i en la estimación del daño. Una posible razón de la peor estimación del daño utilizando la altura de ola total es que la necesidad del uso de una fórmula para el coeficiente de reflexión R añade una nueva dispersión a los resultados.

An investigation on low-crested breakwater has been carried out using physical modeling with the objective of verifying the suitability of using the wave parameters H_50t (average height of the 50 largest total waves) and H_50i (average height of the 50 largest incident waves) in the stability formulations. Additionally, the dependence of the freeboard has been introduced in the mentioned formulations. Experimental tests have been performed on a breakwater structure with a core and a two-layer armour, for three freeboard levels (emerged, at still water level and submerged) at 1:50 scale. The measured and calculated damage values, S, have been compared, considering the different estimations based on the incident wave parameter H_50i and the total wave parameter H_50t. It has been shown that for the structure used in this work, the best fit was obtained using the parameter H_50i. One possible reason for that is the fact that in the estimation of H_50t the need to use a formula for the reflection coefficient R adds new dispersion results.

El uso creciente del recurso hídrico para satisfacer las diferentes demandas de un sistema, muchas veces por encima de su disponibilidad hídrica, ha generado una reducción en el nivel de satisfacción de dichas demandas, así como una reducción en los caudales medioambientales necesarios para alcanzar el buen estado ecológico. A largo plazo, estos problemas pueden verse intensificados como consecuencia del cambio climático. La satisfacción de las demandas de un sistema sin afectar al medio ambiente es uno de los principales objetivos de una eficaz gestión del recurso hídrico. La consideración de unos requerimientos ambientales puede influir en la sensibilidad de un sistema en el momento de satisfacer adecuadamente las diferentes demandas. Este artículo se enfoca en evaluar dicha sensibilidad a largo plazo, mediante el uso de dos indicadores de eficiencia que permiten identificar los problemas de escasez de agua bajo diferentes escenarios de reducciones en las aportaciones. Los requerimientos ambientales se determinaron tomando en cuenta las distribuciones mensuales y anuales de las aportaciones para los diferentes escenarios futuros. Como resultado de aplicar la metodología a la cuenca del Guadalquivir, en España, se observa que los problemas de escasez de agua que actualmente padece la cuenca puedan verse intensificados bajo cambio climático, comprometiendo una adecuada satisfacción de las demandas de agua del sistema. Estos problemas podrían reducirse, e incluso eliminarse, si se consigue limitar el consumo de agua por debajo de la disponibilidad hídrica que presente la cuenca, especialmente en los recursos destinados a la agricultura.

The increasing use of water resources in order to meet the different demands of a system, often above their water availability has led to inadequate attention to such demands, as well as, has generated a reduction in environmental flows needed to achieve good water status. In the long term, these problems may be intensified under climate change scenarios. An adequate attention of the system demands without affecting the environment is one of the main objectives of the water resources management. The consideration of the environmental flows can influence the sensitivity of a system when addressing the different demands. This paper focuses on assessing this sensitivity to long term by using two efficiency indicators, which ones allow to identify water scarcity problems under different scenarios of flows reduction. Environmental requirements are determined by taking into account the monthly and annual distributions of the flows for different future scenarios. The proposed methodology is applied to the Guadalquivir basin in Spain. The results show that the current water scarcity problems of the basin can be intensified when the environmental requirements are considered in the system. These problems could be reduced or even eliminated, if water consumption is limited below the water availability