795 research outputs found

    El factor climático en la erosión del suelo: Erosividad de la lluvia en la cuenca del Ebro

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    La tesis doctoral ha abordado el estudio de la erosividad de la lluvia en la cuenca del Ebro. Aporta un estudio climatológico detallado sobre las dinámicas espacio-temporales de la erosividad de la lluvia en la cuenca del Ebro, sus tendencias y una relación con parámetros de circulación atmosférica. Aporta además un registro experimental de la erosividad de la lluvia natural

    A Multiscalar Global Drought Dataset: The SPEIbase: A New Gridded Product for the Analysis of Drought Variability and Impacts

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    A new multiscalar drought dataset, the SPEIbase, made available to the scientific and management community is presented. The multiscalar character of the dataset allows finding the most appropriate time scale of interest for a specific application, so potential uses of the dataset range over a wide variety of disciplines. The dataset (in three file formats) is distributed under an open license. Further work includes updating the dataset past December 2006, depending on the data availability.This work has been supported by the research projects CGL2008-01189/BTE and CGL2006-11619/HID, funded by the Spanish Commission of Science and Technology and FEDER; EUROGEOSS (FP7-ENV-2008-1-226487) and ACQWA (FP7-ENV-2007-1- 212250), funded by the VII Framework Programme of the European Commission; and “Las sequías climáticas en la cuenca del Ebro y su respuesta hidrológica” and “La nieve en el Pirineo aragonés: Distribución espacial y su respuesta a las condiciones climática,” funded by “Obra Social La Caixa” and the Aragón Government.Peer reviewe

    Hydrologic and landscape changes in the Middle Ebro River (NE Spain): Implications for restoration and management

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    The changes of landscape (1927–2003), discharge regime and anthropic activities with the river-floodplain of one reach at the Middle Ebro River (NE Spain) were investigated with the objective to identify the factors that best explain the natural ecotope succession and propose a realistic restoration option with consideration of the landscape dynamics during the last century and the socio-economic context. Our results indicate that hydrological and landscape patterns have been dramatically changed during the last century as a consequence of human alteration of the fluvial dynamics within the studied reach. The magnitude and variability of river discharge events have decreased at the end of the last century, and flood protection structures have disrupted the river floodplain connectivity. As a result, the succesional pathways of riparian ecotopes have been heavily modified because natural rejuvenation no longer takes place, resulting in decreased landscape diversity. It is apparent from these data that floodplain restoration must be incorporated as a significant factor into river management plans if a more natural functioning wants to be retrieved. The ecotope structure and dynamics of the 1927–1957 period should be adopted as the guiding image, whereas current hydrologic and landscape (dykes, raised surfaces) patterns should be considered. Under the current socio-economic context, the more realistic option seems to create a dynamic river corridor reallocating dykes and lowering floodplain heights. The extent of this river corridor should adapt to the restored flow regime, although periodic economic investments could be an option if the desired self-sustained dynamism is not reached.The research was funded by the Department of the Environmental Science, Technology and University –Aragon government (Research group E-61 on Ecological Restoration)- and MEC (CGL2005-07059). The Spanish Research Council (CSIC) granted Alvaro Cabezas through the I3P program (I3P-EPD2003-2), which was financed by European Social Funds (UE).Peer reviewe

    Influence of the Yesa reservoir on floods of the Aragón River, central Spanish Pyrenees

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    International audienceThe Yesa reservoir, the largest Pyrenean reservoir, was constructed in 1959 to supply water to new irrigated areas in the Ebro Depression, NE Spain. It is filled from October to May-June and then releases large quantities of water in the summer via the Bardenas Canal. The results confirm that the frequency of floods downstream of the dam decreased. The reduction mainly depends on two factors: i) the water storage level, and ii) the season of the year. Floods are very well controlled when the reservoir level is lower than 50%. Between 50 and 70%, only the highest floods are controlled. Finally, the reservoir retains mainly autumn and spring floods; most winter floods are released downstream to ensure the safety of the dam. Keywords: reservoir, flood control, flood seasonality, flood frequency, river regime, Pyrenees</p

    An R package for daily precipitation climate series reconstruction

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    Daily precipitation datasets are usually large, bulky and hard to handle, but they are of key importance in many environmental studies. We developed a tool to create custom datasets from observed daily precipitation records. Reference values (RV) are computed for each day and location using multivariate logistic regression with altitude, latitude and longitude as covariates. The operations were compiled in an Open Source R package called reddPrec. The reddPrec package consists of a set of functions used to: i) apply a comprehensive quality control over original daily precipitation datasets, flagging suspect data based on five predefined criteria; ii) fill missing values in original data series by estimating precipitation values using the 10 nearest observations for each day; and iii) create new series and gridded datasets in locations where no data were recorded

    Hydrologic and landscape changes in the Middle Ebro River (NE Spain): implications for restoration and management

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    The changes of landscape (1927–2003), discharge regime and anthropic activities with the river-floodplain of one reach at the Middle Ebro River (NE Spain) were investigated with the objective to identify the factors that best explain the natural ecotope succession and propose a realistic restoration option with consideration of the landscape dynamics during the last century and the socio-economic context. Our results indicate that hydrological and landscape patterns have been dramatically changed during the last century as a consequence of human alteration of the fluvial dynamics within the studied reach. The magnitude and variability of river discharge events have decreased at the end of the last century, and flood protection structures have disrupted the river floodplain connectivity. As a result, the succesional pathways of riparian ecotopes have been heavily modified because natural rejuvenation no longer takes place, resulting in decreased landscape diversity. It is apparent from these data that floodplain restoration must be incorporated as a significant factor into river management plans if a more natural functioning wants to be retrieved. The ecotope structure and dynamics of the 1927–1957 period should be adopted as the guiding image, whereas current hydrologic and landscape (dykes, raised surfaces) patterns should be considered. Under the current socio-economic context, the more realistic option seems to create a dynamic river corridor reallocating dykes and lowering floodplain heights. The extent of this river corridor should adapt to the restored flow regime, although periodic economic investments could be an option if the desired self-sustained dynamism is not reached

    Contador de amperios -hora basado en Arduino

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    El objetivo de este proyecto es la determinación del estado aproximado de carga de la batería de un sistema fotovoltaico midiendo las corrientes de carga (corriente procedente de un panel fotovoltaico) y descarga (corriente que circula por la carga a alimentar). Para ello se deben elegir y diseñar los sensores correspondientes que midan dichas corrientes y se debe realizar la programación de un microcontrolador (en este proyecto se utilizará un módulo Arduino) para poder mostrar en una pantalla LCD la carga aproximada disponible en la batería del sistema mediante la diferencia de las corrientes medidas y su correspondiente integración en el tiempo. En esta pantalla se podrá observar también el valor de las corrientes de carga y descarga mediante el uso de un pulsador que cambiará el valor a mostrarGraduado o Graduada en Ingeniería Eléctrica y Electrónica por la Universidad Pública de NavarraIngeniaritza Elektriko eta Elektronikoko Graduatua Nafarroako Unibertsitate Publikoa

    The use of long-term high.spatial resolution Normalized Difference vegetation Index (NDVI) to determine different environmental processes in Spain

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    En esta tesis doctoral se han procesado imágenes de los satélites NOAA-AVHRR de 1,1 km de resolución espacial, disponibles durante tres décadas (1981 - 2015) para obtener una base de datos del índice de vegetación NDVI, para la España peninsular y las Islas Baleares, llamada Sp_1Km_NDVI. El método incluye la calibración de la información con los coeficientes de calibración posteriores al lanzamiento de cada satélite, correcciones geométricas y topográficas, la eliminación de nubes, el filtrado temporal de las series y la obtención de compuestos semi-mensales mediante el valor máximo NDVI de las imágenes. Además, la tesis compara la nueva base de datos Sp_1km_NDVI con otras tres bases de datos NDVI. Se ha comprobado si las tendencias anuales y estacionales de la base de datos Sp_1km_NDVI y las otras tres fuentes de información muestran patrones espaciales y tendencias temporales similares. Los resultados muestran que la nueva base de datos proporciona información sobre la actividad vegetal. Es útil para investigar procesos de cambio climático y procesos relacionados con las actividades humanas, en esta región mediterránea. Y permite identificar una tendencia positiva dominante del NDVI durante el periodo de estudio. En el presente trabajo también se han estudiado la relación entre la actividad vegetal y el crecimiento de los anillos de los árboles, en distintos tipos de bosques, bajo diferentes condiciones ambientales. Para ello, la base de datos de imágenes de satélite NDVI se ha combinado con registros dendrocronológicos y datos climáticos para analizar la variabilidad interanual del crecimiento de los anillos de los árboles y la actividad vegetal en distintos biomas forestales desde 1981 y hasta 2015. Los resultados revelan la existencia de una relación positiva y significativa entre la variabilidad interanual del NDVI y el crecimiento de los anillos de los árboles. Sin embargo, esta relación depende del tipo de bosque y de las condiciones ambientales. Finalmente, se han analizado los impactos de la sequía en el NDVI, ya que la sequía es uno de los principales riesgos naturales que afectan a la actividad de la vegetación en España. En esta parte de la tesis se determinan las posibles diferencias en la sensibilidad de la vegetación a la sequía, determinada por los distintos tipos de cubiertas vegetales y por las condiciones climáticas. Y analiza las escalas de tiempo en las que la actividad vegetal está respondiendo a la severidad de la sequía. Los resultados han demostrado que, en grandes áreas de la España peninsular, la actividad vegetal está fuertemente determinada por las variaciones interanuales de la sequía. Sin embargo, existen importantes diferencias estacionales y espaciales en las que el tipo de cubierta y las condiciones de aridez juegan un papel importante. En esta tesis también se ha mostrado que la escala temporal a la que se mide la sequía es muy relevante para entender los diferentes impactos estacionales, e informa sobre la sensibilidad del NDVI a la sequía a nivel estacional y en diferentes coberturas vegetales.<br /

    Modelling tillage and water erosion by usingWATEM/SEDEM and 137Cs measurements at field scale

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    1 Pag.This study applies the WATEM/SEDEM model to estimate soil redistribution rates after calibration with 137Cs measurements. Furthermore, soil redistribution rates by tillage were estimated using the Mass Balance Model 3 (MBM3). A representative Mediterranean cultivated field located in the central part of the Ebro basin (NE Spain) was selected to conduct the study.Peer reviewe

    Geoecology in Mediterranean mountain areas: a tribute to Prof. José María García-Ruiz

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    The origin of this special issue arose from a scientific meeting held in Logroño (Spain) in October 2014, under the theme Geoecology in extreme environments: mountains and semiarid areas (Arnáez et al., 2014). The main motivation of the event was to recognise, on the occasion of his retirement, the outstanding contribution of Prof. José María García-Ruiz to the progress of Geoecology in Mediterranean mountain areas. Prof. García-Ruiz (Zaragoza, 1949) was lecturer, between 1974 and 1987, at the University of Cáceres and La Rioja. As staff Scientist and later Professor at the Spanish National Research Council (CSIC), he was Head of the Pyrenean Institute of Ecology (IPE-CSIC) (1987–1990) and Head of the Department of Global Change at the same institute, President of the Spanish Society of Geomorphology (1994–1996), besides a productive and tireless researcher..
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