14 research outputs found
Environmental flow estimation in two Andalusia basin: combined superficial and groundwater use
Las
líneas de actuación que en políticas de aguas emanan de la Directiva Marco de Aguas (Directiva 2000/60/CE) obligan a considerar nuevos
enfoques en las metodologías hasta ahora empleadas en la gestión del agua, incluyendo elementos innovadores y de mayor eficacia como la
utilización conjunta de aguas superficiales, subterráneas y los caudales ambientales. Varias instituciones y administraciones estatales y
andaluzas están llevando a cabo una serie de trabajos de investigación en dos sistemas de explotación de recursos hídricos que se
localizan en la Comunidad Autónoma de Andalucía. Localizados en la provincia de Jaén y Granada ambos presentan peculiaridades
interesantes en cuanto a la circulación del agua subterránea. El objetivo de estos trabajos es desarrollar y aplicar tecnologías que integren
criterios medioambientales (caudales ecológicos), económicos (coste del agua suministrada) y de gestión. Los resultados muestran como,
aplicando criterios de eficacia y uso conjunto, es posible mantener unos caudales ambientales en el primer sistema, y como los caudales
ambientales que se proponen en el segundo sistema serían fundamentales para mantener la estructura y composición del ecosistema ripario
de la cuenca estudiada.Water policies derived from
the Water Framework Directive (Directive 2000/60/CE) emphasize the need to incorporate new approaches in water management, including
innovative and more efficient approaches such as combined use of surface and ground water, and environmental flow. A number of
Spanish and Andalusian institutions and administrations are currently developing research programs on 2 water resource systems in Jaén
and Granada (Andalusia). Both of them show interesting peculiarities in terms of ground water flows. The objective of this work is to
develop and apply technologies that integrate ecological (environmental flow), economic (cost of water) and management criteria. Results
from the Jaén area show that the maintenance of environmental flows is possible when the principles of efficiency and combined use are
applied; in Granada, the recommended environmental flow is crucial to maintain the structure and composition of riparian ecosystems
Critical analysis of method used to establish environmental flows in the Segura river basin
Minimum environmental flows can be calculated by different methodologies. The main methods habitually used in Spain can be grouped under the headings of Hydrological or Habitat Simulation methodologies. As part of the planning process established by the WFD, the Subdirectorate General for Water Planning and Sustainable Use of the Spanish Environment Ministry has developed a standard that sets out the specific way in which these methodologies must be used to determine minimum environmental flows.
In the present work, minimum environmental flow values have been determined using different criteria on nine reaches in the Segura river basin (Spain), on the main course and in several tributaries. Calculations have been made by the most habitual methods and considering the official flow estimation criteria defined in the Segura Basin Management Plan and Spanish Environment Ministry recommendations, including those set out in the new Hydrologic Planning Regulation (RPH). The results obtained have then been analysed and compared. The values obtained using the official methodologies and instructions have been evaluated taking into account the criterion of the water lamina created on each reach and considering whether this is adequate for fish movement.Departamento de Ecología de la Universidad Autónoma de Madrid. Ecohidraulica S.L., Madrid. España
The natural variability approach. Application to the analysis of the hydrologic alteration in five rivers (Ebro basin, Spain)
Artículo internacional que aplica los criterios de NVA (Natural Variability Approach) a cinco ríos de la cuenca del Ebr
Dam function rules based on brown trout flow requirements: design of environmental flow regimes in regulated streams
The operation of small hydroelectric dams built on mountain streams induce changes in stream flow regimes that are manifested not only in the intensity of flow events, but also in the variability and frequency of high- and low-flow episodes. Former studies have shown the influence of flow variability upon the dynamics of a resident brown trout population, especially that related to the stream flow regime during spawning, incubation and emerging periods. As these life-stages are known to determine the population dynamics in further ages, stream flow variability appears to be a major influence on the regulation of a wild brown trout population. Thus, mean flow discharge should not be the only parameter taken into account when establishing ecological flow regimes to support rehabilitation of degraded trout populations in mountain streams. Ecological stream flow regime characteristics are proposed as a basis for the design of environmental flow regimes in mountain reaches downstream of hydroelectric or water supply dams. Case studies were conducted in a high mountain basin in Central Spain (River Tormes) for a period of 5 years showing that relationship between duration and frequency of high and low flow episodes during egg incubation could be linked to young-of-the-year recruitment and quantified in terms of flow management units. Duration and frequency of flow discharges could be manipulated so as to create favourable hydrological conditions for restoring sustainable populations of brown trout in rivers affected by flow regulatio
Definición del potencial ecológico en aguas fuertemente modificadas: aplicación en el tramo medio del río Tajo
El objetivo de este trabajo es doble, por un lado medir el grado de alteración hidrológica al que se ven sometidas las masas de agua del tramo medio del río Tajo, debido a la regulación de caudales, lo que las clasifica como masas hidrológicamente alteradas. En segundo lugar tratar de relacionar el grado de alteración hidrológica, con el estado ambiental definido por varios indicadores hidrobiológicos: bentos, macrófitas, peces y estado de las riberas
Caracterización de las formaciones riparias para la clasificación tipológica de los ríos de Navarra, y evaluación de su estado ecológico mediante la aplicación de dos índices de calidad de ribera (RQI y QBR): Comparación entre ellos
Este estudio se enmarca dentro de las medidas llevadas a cabo por el Gobierno de Navarra para alcanzar los objetivos dictados por la Directiva Marco de Agua, DMA. Para la consecución de la evaluación del estado ecológico de los ríos, previamente se deben realizar los estudios de caracterización física y de sus cuencas vertientes obteniendo una tipología de los segmentos fluviales (DMA, artículo 3, anexo II). Hasta el momento se carecía de trabajos de síntesis que ofreciesen una visión de conjunto sobre la vegetación de las riberas en Navarra. Este tipo de trabajos resulta de gran utilidad para la identificación de tramos de ríos con elevado valor ecológico y posibilita la selección adecuada de especies vegetales para la recuperación de ríos degradados, utilizando las plantas más adecuadas, desde el punto de vista territorial y ambientalmente, para cada situación. En este estudio se aporta más información a cada uno de los tipos fluviales presentes en Navarra y se evalúa su interrelación teniendo en cuenta aspectos morfológicos y de ribera. Para ello, se ha realizado una caracterización de las diferentes formaciones riparias, atendiendo a las condiciones de cuenca vertiente y características morfológicas de los tramos en los que se ubican cada una de ellas. Con el objetivo de realizar un mejor enfoque en las medidas de restauración que se establezcan para cada tipo fluvial, se ha evaluado también la calidad ecológica de las riberas según la cuantificación establecida por dos índices distintos: QBR y RQI, determinando en qué aspectos éstas se encuentran más degradadas para cada uno de los tipos fluviales. Para completar los resultados se ha llevado a cabo un análisis de las relaciones entre los diferentes parámetros utilizados, evaluando cómo funcionan los índices QBR y RQI. Este análisis proporciona las bases para la determinación de las condiciones de referencia para cada uno de los tipos fluviales, necesarias para establecer una clasificación de calidades
La freza de la trucha común en la cuenca alta del río Cabriel. Resultados y utilidad para la gestión
ECOHIDRÁULICA realiza actualmente el estudio hidrobiológico de la cuenca alta del río Cabriel, para la Junta de Castilla-La Mancha. En el marco de este proyecto se ha estudiado la freza de la trucha común (Salmo trutta L.). El trabajo de campo ha sido realizado, durante el invierno 2007-2008, por Agentes de la Junta, que han tomado datos de los frezaderos detectados en cada tramo muestreado. Se ha registrado: ubicación del tramo, fecha del muestreo, tipo de hábitat, número de frezaderos en el tramo, solapamiento, ubicación dentro del tramo y dimensiones de los frezaderos, problemática y, en caso de ser observada, características de la acción de freza
Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study
PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.
PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
A comparative analysis of methods for establishing environmental flows in a Mediterranean watershed: suggestions for management
In Spain, the largest inter-basin transfer is between the Tagus and Segura Basins. This transfer affects the regimes of the Mundo River, a tributary, and the Segura River. In this study, we examine two methodologies for the calculation of environmental flow regimes for the stretches affected by this alteration. When several methodologies are used to determine environmental flows, difficulty arises in deciding which values to propose to restore the river system hydrologically. This work tries to overcome this problem because we present a proposal to make them complementary. As a method for establishing the validity of minimum flow results, a simulation has been carried out on the river section, which has made it possible to evaluate the habitat created and the possibility of fauna movement. The results obtained by the habitat simulation method exceeded those obtained by hydrological methods in terms of habitat creation and hydraulic conditions for connectivity. These same tests have been used to assess the minimum official proposal made by the water administration.
HIGHLIGHTS
A procedure has been established that allows different results of ecological minimum flow values to be used in a complementary way to improve fish habitat.;
When results obtained by several methodologies are used in a complementary way, a more robust ecological flow regime proposal can be made.;
The method used can be applied together with other restoration measures in river stretches with strong morphological alterations.