Aina G. Gómez

Flushing time as a descriptor for heavily modified water bodies classification and management: application to the Huelva Harbour.

Since the flushing time is a physical descriptor used to distinguish between different types of heavily modified water bodies (HMWB), the establishment of a methodology for its calculation becomes important. In order to achieve this task, a methodological procedure involving the tide mean value and variable river flow values is proposed. The hydrodynamics were assessed using a two-dimensional model which integrates the depth-averaged mass and momentum equations in the time and space domains and includes a wet-dry point treatment method. The hydrodynamic model calibration and validation were performed on the basis of tidal gauge and velocity current measurements. A reasonable agreement with the field measurements of water elevation and velocity were achieved. On the other hand, a two-dimensional mathematical model, which solves the depth-averaged advection-diffusion equation, was properly calibrated and used to evaluate the behaviour of a conservative tracer within a water body. The transport model calibration was developed according to the field survey data carried out during late spring when the rivers flows are low. This study allowed the flushing time estimation under four scenarios showing that only the estuarine mouth presents a high renewal rate because the current velocities are higher. For heavy rain periods, a flushing time decrease was observed as river flows modify the circulation in the main channel. Neglecting the river forcing was found to be valid for the dry period.

Environmental risk analysis of oil handling facilities in port areas. Application to Tarragona harbor (NE Spain)

Diffuse pollution from oil spills is a widespread problem in port areas (as a result of fuel supply, navigation and loading/unloading activities). This article presents a method to assess the environmental risk of oil handling facilities in port areas. The method is based on (i) identification of environmental hazards, (ii) characterization of meteorological and oceanographic conditions, (iii) characterization of environmental risk scenarios, and (iv) assessment of environmental risk. The procedure has been tested by application to the Tarragona harbor. The results show that the method is capable of representing (i) specific local pollution cases (i.e., discriminating between products and quantities released by a discharge source), (ii) oceanographic and meteorological conditions (selecting a representative subset data), and (iii) potentially affected areas in probabilistic terms. Accordingly, it can inform the design of monitoring plans to study and control the environmental impact of these facilities, as well as the design of contingency plans.

Assessment of susceptibility to pollution in littoral waters using the concept of recovery time

Susceptibility to pollution can be related to the flushing capacity of aquatic systems. Transport time scales constitute a useful tool for representing the water exchange and transport processes. A new transport time scale, recovery time, and a methodology to estimate it by means of numerical models is hereby developed. Recovery time, calculated in Gijon, Santander and Tarragona harbours, is significantly related to physical, chemical and biological water quality indicators. Susceptibility, assessed through recovery time values, provides spatial patterns of expected flushing capacity, being sensitive to physical and hydrodynamic characteristics. The developed method is appropriate to estimate recovery time and assess susceptibility against pollution in littoral waters having great potential to be applied to different disciplines. Recovery time could be used in littoral waters as a surrogate of water quality indicators, to establish efficient monitoring programs, to define and characterize modified water bodies or to improve the design of marine infrastructures.

Transport time scales as physical descriptors to characterize heavily modified water bodies near ports in coastal zones

Physical descriptors that characterize Heavily Modified Water Bodies (HMWB) based on the presence of ports should assess the degree of water exchange. The main goal of this study is to determine the optimal procedure for estimating Transport Time Scales (TTS) as physical descriptors in order to characterize and manage HMWB near ports in coastal zones. Flushing Time (FT) and Residence Time (RT), using different approaches-analytical and exponential function methods-and different hydrodynamic scenarios, were computed using numerical models. El Musel (Port of Gijon) was selected to test different transport time scales (FT and RT), methods (analytical and exponential function methods) and hydrodynamic conditions (wind and tidal forcings). FT, estimated by the exponential function method while taking into account a real tidal wave and a mean annual regime of wind as hydrodynamic forcing, was determined to be the optimal physical descriptor to characterize HMWB.

Environmental risk assessment of water quality in harbor areas: a new methodology applied to European ports.

This work presents a standard and unified procedure for assessment of environmental risks at the contaminant source level in port aquatic systems. Using this method, port managers and local authorities will be able to hierarchically classify environmental hazards and proceed with the most suitable management actions. This procedure combines rigorously selected parameters and indicators to estimate the environmental risk of each contaminant source based on its probability, consequences and vulnerability. The spatio-temporal variability of multiple stressors (agents) and receptors (endpoints) is taken into account to provide accurate estimations for application of precisely defined measures. The developed methodology is tested on a wide range of different scenarios via application in six European ports. The validation process confirms its usefulness, versatility and adaptability as a management tool for port water quality in Europe and worldwide.

Can a GIS toolbox assess the environmental risk of oil spills? Implementation for oil facilities in harbors

Oil spills are one of the most widespread problems in port areas (loading/unloading of bulk liquid, fuel supply). Specific environmental risk analysis procedures for diffuse oil sources that are based on the evolution of oil in the marine environment are needed. Diffuse sources such as oil spills usually present a lack of information, which makes the use of numerical models an arduous and occasionally impossible task. For that reason, a tool that can assess the risk of oil spills in near-shore areas by using Geographical Information System (GIS) is presented. The SPILL Tool provides immediate results by automating the process without miscalculation errors. The tool was developed using the Python and ArcGIS scripting library to build a non-ambiguous geoprocessing workflow. The SPILL Tool was implemented for oil facilities at Tarragona Harbor (NE Spain) and validated showing a satisfactory correspondence (around 0.60 RSR error index) with the results obtained using a 2D calibrated oil transport numerical model.

The Influence of Hydromorphological Stressors on Estuarine Vegetation Indicators

Estuaries are one of the most threatened ecosystems, with a great number of stressors related to pollution, hydromorphological changes, and invasive species. However, the response of the biological indicators proposed for their ecological status assessment is not always well established. When using estuarine vegetation (saltmarshes and seagrasses) as an indicator, there are several theoretical concepts regarding the relationships between the variations of this indicator and hydromorphological stressors. It is precisely these relationships which are presented in this work. To carry out this objective, based on the first intercalibration process, a set of metrics for saltmarsh and seagrass taxonomic compositions (e.g., loss of number of taxa and richness) and abundance (e.g., relative coverage and relative extent) have been selected and applied to different estuaries located in Northern Spain. Additionally, a methodology for the hydromorphological status assessment, based on the analysis of the anthropogenic changes in the hydrodynamic and morphological estuarine characteristics (e.g., the extension of land claim areas or changes in the estuarine perimeter), has been developed and applied to these transitional water bodies in order to find a gradient of pressured sites in which we seek correlations between the vegetation metrics and hydromorphological stressors. As a result, the response of the different vegetation indicators is variable. In some cases, a negative correlation of the indicator with the pressure degree exists, whereas in other cases, the relationship is not as clear. Nonetheless, according to the results, it can be suggested that the placing of anthropogenic structures diminishes the quality of the estuarine vegetation. Therefore, to maintain a suitable environment for the estuarine vegetation seems necessary in order to reduce the number of the hydrodynamic structures which are no longer in use.

Prioritization maps: The integration of environmental risks to manage water quality in harbor areas

A method to integrate the environmental risk of the multiple effects from uses and activities developed in harbor areas is presented. Consequences are considered as the effects derived from all identified hazards. Vulnerability is expressed in terms of functional relations between environmental susceptibility against a disturbance and the state of protection of the receptors at risk. Consequences and vulnerability are integrated obtaining a spatial variation of risk: prioritization maps. The maps are developed by 4 main stages: (1) environmental hazard identification; (2) estimation of the consequences; (3) estimation of vulnerability and, (4) integration of environmental risks. To adapt prioritization maps to the peculiarities of the study area, three different methods for the integration of the effects are proposed: average-value, worst-case and weighted methods. The implementation to a real case (Tarragona harbor, NE Spain) confirms its usefulness as a risk analysis tool to communicate and support water quality management in harbors.

Resultados de la gammagrafía de perfusión miocárdica con 99mTc-tetrofosmina y estímulo con dipiridamol en pacientes diagnosticados de angina microvascular

Resumen —El objetivo del estudio fue analizar los resultados de la gammagrafia de perfusion miocardica con 99m Tc-tetrofosmina (Tc-Tf) y estimulo con dipiridamol en pacientes diagnosticados de angina microvascular. La poblacion de estudio esta compuesta por 50 pacientes que habian sido dados de alta con el diagnostico de angina microvascular y a los que se habia realizado Tc-Tf-dipiridamol. La prueba fue clinica y electricamente positiva en el 40% y el 12% de los casos, respectivamente. Se encontraron defectos de perfusion en 35 pacientes (70%), que fueron reversibles en 21 (60%), fijos en 11 (21%), y mixtos en 3 (9%). En cuanto a la localizacion de los defectos de perfusion, esta fue en el territorio de la coronaria derecha en 21 pacientes, de la descendente anterior en 18, y de la circunfleja en 2. Los pacientes que habian realizado una prueba de esfuerzo positiva, en comparacion con los que habian realizado una ergometria negativa, presentaron mas frecuentemente defectos de perfusion (91% vs 50%, p = 0,0327) e isquemia gammagrafica (64% vs 20%, p = 0,392). La aparicion de angina fue mas frecuente en mujeres que en varones (56% vs 22%, p = 0,013), asi como la existencia de defectos de perfusion en el territorio de la arteria descendente anterior (26% vs 4%, p = 0,028). Los varones, por el contrario, mostraron mas frecuentemente defectos de perfusion en la cara inferior (57% vs 30%, p = 0,057). En conclusion, el Tc-Tf-dipiridamol muestra alteraciones de la perfusion en el 70% de los pacientes diagnosticados de angina microvascular, siendo esta proporcion del 91% en pacientes con ergometria positiva. El patron gammagrafico en estos pacientes puede estar condicionado, en parte, por el sexo.