21 research outputs found
Desalinisation of seawater in Spain: Aspects to be considered in the design of the drainage system to protect the marine environment
RESUMEN. La puesta en marcha del vigente Plan Hidrológico Nacional implica un aumento significativo de la desalinización de agua marina como fuente de recurso hídrico en las cuencas costeras españolas, y con ello, del caudal de salmuera generado y vertido al Mar Mediterráneo, con riesgo de afección negativa sobre sus hábitats. El presente artículo ofrece a técnicos y gestores una visión completa y un análisis sobre los principales aspectos a considerar en los estudios de vertido al mar de la salmuera: efectos y umbrales críticos de salinidad para ecosistemas del Mar Mediterráneo, sistemas de descarga, comportamiento del efluente en el medio receptor, formulaciones matemáticas, herramientas y software de modelización disponibles y planes de vigilancia. Se concluye con una serie de recomendaciones de utilidad para el diseño de estos sistemas de vertido.ABSTRACT. The introduction of the new National Water Plan has implied a significant increase in the desalinisation of seawater as a source of water supply to the Spanish coastal basins. This has, in turn, generated a flow of brine that is discharged into the Mediterranean with potentially negative effects for the marine environment. The present article offers technicians and administrators a complete view and analysis of the main aspects to be considered in studies on the drainage of brine into the sea: the effects and critical thresholds of salinity for the ecosystems of the Mediterranean; drainage systems; behaviour of the effluent in the receiving medium; mathematical formulae, available modelling tools and software; and monitoring plans. The article concludes with a series of recommendations for the design of these drainage systems
Wave attenuation modelling by submerged vegetation: ecological and engineering analysis
The correct address of wave characteristics in the vicinity of submerged vegetation is crucial to perform an ecological analysis. Although several attempts have been done in the past using an analytical approach or depth averaged models, the rigidity of the assumptions used to solve the physics produced limited application to real cases. The use of a NS model called IH-2VOF is used first to minimize the number of predefined assumptions for wave propagation and the non-linear interactions between waves and plants and second to explore the possibility to improve existing turbulence models to consider wave interaction with vegetation. The IH2-VOF model has been validated using large scale experiments developed by Stratigaki et al. (2011). The model has shown a high degree of accordance between the lab data and the numerical predictions in free surface evolution. Numerical predictions of the velocity field have been compared both over and inside the vegetation showing also a high degree of accordance. Drag coefficients obtained during the model calibration are in accordance with previous studies such as Mendez et al. (1999). The influence of wave height, wave period, water depth and patch density have been studied using additional numerical simulations with irregular waves. Both the wave period and the water depth have been revealed as the most important parameters in the modification of the flow patterns around the patch
Estructura flotante e instalación para el aprovechamiento de la energía del oleaje utilizando un catamarán flotante con varias cámaras de columna de agua oscilante.
Una estructura flotante para el aprovechamiento de la energía del oleaje, que comprende múltiples cámaras independientes de columna de agua oscilante (CAO) alineadas, abiertas por el fondo, estando cada cámara comunicada por la parte superior con la atmósfera a través de un grupo turbo-generador formado por un conducto de aire, en cuyo interior se ubican una válvula de control del flujo de aire y una turbina de aire auto-rectificadora conectada a un alternador.Solicitud: 201100242 (28.02.2011)Nº Pub. de Solicitud: ES2387492A1 (24.09.2012)Nº de Patente: ES2387492B2 (26.03.2013
Forces induced on a vertical breakwater by incident oblique waves
Over the last years Navier-Stokes numerical models have been developed to accurately simulate wave interaction with all kinds of coastal structures, focusing on both functionality and stability of coastal structures. Although several models have been used to simulate wave interaction with coastal structures in two dimensions (2DV) there are a vast number of three-dimensional effects that need to be investigated in order to improve the design. In this paper a new model called IH-FOAM has been applied to study a vertical breakwater at prototype scale. As a first attempt of validation, the model has been used to simulate a regular wave train generated with a relative angle with the breakwater inducing three-dimensional wave patterns not only seaward the structure due to reflection but also generating an overtopping discharge variation along the breakwater trunk. Pressure laws and overtopping discharge at three different cross-sections along the structure have been studied. The pressure laws have been compared with classical Goda’s formulation. Although, the numerical model predictions are in accordance with Goda’s calculations, a clear three-dimensional variability of wave-induced pressure has been observed. Moreover, an additional study has been performed calculating pressure laws on the side-wall at the breakwater head. Large three-dimensional effects are detected from the simulations due to the flow separation at that area. Overtopping model predictions have been compared with Overtopping Manual calculations showing very close values along the trunk. However, lower overtopping discharge values are observed at the breakwater head. This paper is a preliminary work to show the range of applicability of a three-dimensional Navier-Stokes model to study wave interaction with a vertical breakwater under the action of an oblique wave train
Plataforma semisumergible para aplicaciones en mar abierto
Una plataforma semisumergible que comprende: una columna interior y al menos cuatro columnas exteriores, donde cada una de dichas columnas interior y exteriores comprenden una base resistente y un tronco, y donde cada columna comprende una sección de mayor resistencia a una determinada altura y una pluralidad de vigas que unen cada columna exterior con la columna interior y cada columna exterior con cada columna exterior adyacente. Un método de construcción de una plataforma semisumergible.Solicitud: 201200760 (18.07.2012)Nº Pub. de Solicitud: ES2387232A1 (18.09.2012)Nº de Patente: ES2387232B2 (03.02.2014
Plataforma semisumergible triángular para aplicaciones en mar abierto
Una plataforma semisumergible que comprende: una columna interior configurada para dotar de mayor flotabilidad y tres columnas exteriores, donde cada una de dichas columnas interior y exteriores comprenden una base resistente y un tronco, y donde cada columna comprende una sección de mayor resistencia a una determinada altura y una pluralidad de vigas que unen cada columna exterior con la columna interior y cada columna exterior con las otras dos columnas exteriores. Un método de construcción de una plataforma semisumergible.Solicitud: 201200759 (18.07.2012)Nº Pub. de Solicitud: ES2387342A1 (20.09.2012)Nº de Patente: ES2387342B2 (10.02.2014
Impact of dynamical regionalization on precipitation biases and teleconnections over West Africa
West African societies are highly dependent on the West African Monsoon (WAM). Thus, a correct representation of the WAM in climate models is of paramount importance. In this article, the ability of 8 CMIP5 historical General Circulation Models (GCMs) and 4 CORDEX-Africa Regional Climate Models (RCMs) to characterize the WAM dynamics and variability is assessed for the period July-August-September 1979-2004. Simulations are compared with observations. Uncertainties in RCM performance and lateral boundary conditions are assessed individually. Results show that both GCMs and RCMs have trouble to simulate the northward migration of the Intertropical Convergence Zone in boreal summer. The greatest bias improvements are obtained after regionalization of the most inaccurate GCM simulations. To assess WAM variability, a Maximum Covariance Analysis is performed between Sea Surface Temperature and precipitation anomalies in observations, GCM and RCM simulations. The assessed variability patterns are: El Nio-Southern Oscillation (ENSO); the eastern Mediterranean (MED); and the Atlantic Equatorial Mode (EM). Evidence is given that regionalization of the ENSO-WAM teleconnection does not provide any added value. Unlike GCMs, RCMs are unable to precisely represent the ENSO impact on air subsidence over West Africa. Contrastingly, the simulation of the MED-WAM teleconnection is improved after regionalization. Humidity advection and convergence over the Sahel area are better simulated by RCMs. Finally, no robust conclusions can be determined for the EM-WAM teleconnection, which cannot be isolated for the 1979-2004 period. The novel results in this article will help to select the most appropriate RCM simulations to study WAM teleconnections
Efectos del Cambio Climático en la costa de América Latina y el Caribe: generación de bases de datos climáticos para el análisis de riesgos en las costas de Santa Catarina (Brasil). Resumen para gestores
En este documento de síntesis se presenta el Resumen para Gestores del proyecto “Generación e integración de bases de datos climáticos históricos y de proyecciones de cambio climático para la gestión de riesgos costeros en el estado de Santa Catarina (Brasil)”, financiado por el acuerdo de cooperación técnica entre la Comisión Económica para América Latina y el Caribe (CEPAL) y el Ministerio del Medio Ambiente del Brasil, "Desarrollo sostenible y su integración con América del Sur", coordinado por la Oficina de la CEPAL en Brasilia.I. Contexto general .-- II. El estudio de Santa Catarina, Brasil .-- III. Otras aplicaciones
Plataforma semisumergible triángular para aplicaciones en mar abierto
ABSTRACT: The invention relates to a semi-submersible platform comprising: an inner column designed to improve buoyancy and three outer columns, in which each of the inner and outer columns is made from reinforced concrete and comprises a resistant base, a shaft and a section located at a pre-determined height and having greater resistance. The semi-submersible platform also comprises a plurality of beams at the aforementioned pre-determined height, which connect each outer column to the inner column and to the other two outer columns, and a plurality of anchor lines designed to be anchored to the more resistant section of each outer column. The semi-submersible platform also comprises a lower plate on which the columns are secured and which is reinforced with a plurality of beams that connect the base of each outer column to the base of the inner column and to the base of the other two outer columns. The invention relates to a method for the construction of a semi-submersible platform.RESUMEN: Una plataforma semisumergible que comprende: una columna interior configurada para dotar de mayor flotabilidad y tres columnas exteriores, donde cada una de dichas columnas interior y exteriores son de hormigón armado y comprenden una base resistente, un tronco y una sección de mayor resistencia a una determinada altura. La plataforma semisumergible comprende además una pluralidad de vigas a dicha determinada altura que unen cada columna exterior con la columna interior y con las otras dos columnas exteriores, y una pluralidad de líneas de fondeo configuradas para ser ancladas a la sección de mayor resistencia de cada columna exterior. La plataforma semisumergible comprende además una placa inferio sobre la que se fijan las columnas reforzada por una pluralidad de vigas que conectan la base de cada columna exterior con la base de la columna interior y con la base de las otras dos columnas exteriores. Un método de construcción de una plataforma semisumergible.Solicitud Internacional: PCT/ES2013/000164 (05.07.2013)Nº Pub. Solicitud Internacional: WO2014/013097A1 (23.01.2014
Skillful prediction of tropical Pacific fisheries provided by Atlantic Niños
12 pages, 4 figures.-- Data availability Annual catch data from FAO major fishing areas are available from the Sea Around Us Project (http://www.seaaroundus.org/data/#/fao). Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) are available from the Met Office Hadley Centre observations datasets (https://www.metoffice.gov.uk/hadobs/hadisst/). National Centers for Environmental Prediction (NCEP) reanalysis data are available from the NOAA/OAR/ESRL PSL website (https://psl.noaa.gov/). GFDL COBALT and FishMIP simulation data (EcoOcean, BOATS and Macroecological) are accessible through the Potsdam-Institute for Climate Impact Research Earth System Grid Federation (ESGF) data node (https://esg.pik-potsdam.de/search/isimip/). Code availabilityS4CAST originally published MATLAB® code is open access and available from the Zenodo repository (doi:10.5281/zenodo.15985) in the URL https://zenodo.org/record/15985. The rest of MATLAB scripts used in this analysis can be made available upon request from the corresponding author ([email protected]). Updated S4CAST versions can be requested to the TROPA-UCM research group ([email protected])Tropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Niño Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical PacificThis research was funded by the EU H2020 project TRIATLAS (no. 817578), the Universidad Complutense de Madrid project FEI-EU-19-09 and the Spanish Ministry of Economy and Competitiveness project PRE4CAST (CGL2017-86415-R).With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe