429 research outputs found

    The influence of nitrate leaching through unsaturated soil on groundwater pollution in an agricultural area of the Basque country: a case study

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    The average nitrate concentration in the groundwater of the Vitoria-Gasteiz (Basque Country) quaternary aquifer rose from 50 mg NO3−/l during 1986 to over 200 mg/l in 1995, which represents an increase of some 20 mg NO3−/l per year. From 1995 to 2002, the nitrate concentration of the groundwater slightly decreased. Nitrategroundwaterpollution during the period 1986–1993 was the result of the abusive use of fertilizers and of the modification in the recharge patterns of the aquifer from surface water sources. From 1993 onwards, apart from a possible rationalization in fertilizer use, the change in the origin of water for irrigation and wetland restoration (water is taken now from artificial pools outside the quaternary aquifer) must be explained in order to account for the observed decrease in nitrate concentration in the groundwater. The water of the aquifer and of the unsaturated zone were studied in two experimental plots (one of them cultivated and the other uncultivated) for 18 months (January 1993–June 1994), during the period of maximum contamination, to evaluate the effect of fertilizers on soil water and on the water in the saturated zone. The soil water was sampled using soil lysimeters at various depths. The volumetric water content of the soil was measured at the same depths using time domain reflectrometry (TDR) probes. Samples of groundwater were taken from a network of wells on the aquifer scale, two located close to the two experimental plots. The temporal evolution of nitrate concentrations in soil solutions depends on the addition of fertilizers and on soilnitrateleaching by rain. During episodes of intense rain (>50 mm in a day), the groundwater deposits are recharged with water coming from the leaching of interstitial soil solutions, causing an increase in the groundwaternitrate concentrations. The mass of nitrate leached from the cultivated zone is five times higher than that of the nitrate leached from the uncultivated zone (1147 kg NO3−/ha in the cultivated sector as against 211 kg NO3−/ha in the uncultivated sector), although part of the nitrate leached into the soil had been previously deposited by the rise of the water table. If we consider that the level of groundwater input is similar in both plots, we may conclude that 964 kg NO3−/ha circulated towards the groundwater in the cultivated zone during the period under study, representing 87% of the nitrate applied to the soil in the form of fertilizer during that period

    Eliminación de nitratos por desnitrificación en la zona no saturada del suelo en un humedal del cinturón Peri-Urbano de Vitoria-Gasteiz

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    Los cambios de usos del suelo y la intensificación de la agricultura en el acuífero cuaternario de Vitoria-Gasteiz llevaron a la desaparición de los humedales. Acciones recientes de restauración en el área peri-urbana han llevado a su recuperación. La restauración de estas zonas húmedas ha contribuido a la disminución de nitratos de las aguas subterráneas. Las concentraciones en NO3 -, superiores a 50 mg NO3 -/L en las aguas fluyentes hacia la zona húmeda, son inferiores a 10 mg NO3 -/L en los alrededores del humedal. Se ha medido el potencial de desnitrificación de los suelos en la zona no saturada mediante en método de bloqueo con acetileno en tres perfiles de suelo adyacentes al humedal a tres profundidades representativas del suelo del depósito aluvial. Los valores máximos de desnitrificación se observan en los horizontes superficiales ricos en materia orgánica (32,0 – 36,2 g MO/kg suelo) con tasas de desnitrificación que varían entre 18,7 y 20,3 mg N/día*kg de suelo. Los contenidos en materia orgánica disminuyen en profundidad (4,3 – 5,7 g MO/kg suelo en el horizonte B2 entre 70 y 100 cm de profundidad). En este horizonte se han medido las tasas de desnitrificación mas bajas con valores que varían entre 0,1 y 1,1 mg N/día*kg de suelo

    Aplicación del modelo stics para la determinación de la lixiviación de nitratos bajo cultivo de remolacha azucarera en la zona no saturada del suelo

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    Se ha aplicado el modelo STICS a los datos de una parcela experimental de remolacha azucarera situada en la localidad de Matauko, dentro de la Zona Vulnerable del acuífero cuaternario de Vitoria-Gasteiz. En dicha parcela se aplicaron seis tratamientos diferentes y se estudió la lixiviación de nitratos en cuatro de las aplicaciones. El objetivo de este estudio ha sido comparar los resultados del modelo con los obtenidos en el campo. Se han modelizado cuatro de los tratamientos aplicados en la parcela, simulando a nivel diario el balance de agua y de nitrógeno (kg N/ha) en suelo y planta. Los resultados del modelo coinciden bien con los experimentales, sobre todo en los momentos de episodios claros de infiltración, y en la evolución de la concentración en nitratos, con una notable disminución en las concentraciones en la parte final del periodo considerado

    Spatial variability in threshold temperatures of heat wave mortality: impact assessment on prevention plans

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    Spain’s current heat wave prevention plans are activated according to administrative areas. This study analyses the determination of threshold temperatures for triggering prevention-plan activation by reference to isoclimatic areas, and describes the public health benefits. We subdivided the study area – the Madrid Autonomous Region (MAR) – into three, distinct, isoclimatic areas: ‘North’, ‘Central’ and ‘South’, and grouped daily natural-cause mortality (ICD-10: A00-R99) in towns of over 10,000 inhabitants (2000–2009 period) accordingly. Using these three areas rather than the MAR as a whole would have resulted in a possible decrease in mortality of 73 persons (38– 108) in the North area, and in aborting unnecessary activation of the plan 153 times in the Central area and 417 times in the South area. Our results indicate that extrapolating this methodology would bring benefits associated with a reduction in attributable mortality and improved effectiveness of public health interventions.This study was funded by a ‘Miguel Servet type 1’ grant (SEPY 1037/14), as well as a Health Research Fund grant (Fondo de Investigaciones Sanitarias/FIS Project ENPY1133/16 from the Carlos III Institute of Health

    Impact of urban heat islands on morbidity and mortality in heat waves: observational time series analysis of Spain's five cities

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    Urban heat islands (UHIs) have become an especially relevant phenomenon as a consequence of global warming and the growing proportion of people living in cities. The health impacts that are sometimes attributed to the rise in temperature generated in an UHI are not always adequately justified. The objective is to analyse what effect UHIs have on maximum (Tmax) and minimum daily temperatures (Tmin) recorded in urban and non-urban observatories, and quantify the impact on morbidity and mortality during heat waves in Spain's five cities

    Propiedades físico-químicas de jamones elaborados con carne pálida, suave y exudativa de cerdo

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    Los objetivos del presente estudio fueron evaluar las propiedades físico-químicas de jamones elaborados con 0, 10 y 20% de carne de cerdo con características pálida, suave y exudativa, así como determinar el rendimiento en jamón al adicionar carragenina como agente ligador. Los datos fueron analizados estadísticamente en un diseño de cuadro latino con cuatro repeticiones por tratamiento en el experimento 1 y tres en el experimento 2, y las medias fueron sometidas a contrastes ortogonales. No hubo efecto (P>0.05) de los porcentajes de carne pálida, suave y exudativa y del almacenamiento en el color, pH, esfuerzo de corte, capacidad de retención de agua y proteína total. La calidad sensorial no fue diferente (P>0.05) entre el jamón PSE y el control, no obstante el jamón con el 20% mostró (P>0.05) la mayor pérdida por cocimiento y almacenamiento. La adición de los niveles de carne disminuyó (P0.05). La adición de carragenina no modificó (P>0.05) la capacidad de retención de agua, esfuerzo de corte, color y calidad sensorial de los jamones normales y con C-PSE, pero sí redujo (P>0.05) la pérdida de peso por cocimiento y por almacenamiento. Los resultados sugieren que la adición de hasta un 20% de C-PSE y carrageninas para los jamones reestructurados no tiene efectos perjudiciales en la calidad del producto. DOI: https://doi.org/10.54167/tecnociencia.v1i1.32

    Umbrales de definición de ola de frío e impacto sobre la mortalidad en España. Necesidad de Planes de prevención

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    Ponencia presentada en: XXXIV Jornadas Científicas de la AME y el XVII Encuentro Hispano Luso de Meteorología celebrado en Teruel, del 29 de febrero al 2 de marzo de 2016

    Determinación de umbrales de definición de ola de calor e impacto sobre la mortalidad en España

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    Ponencia presentada en: XXXIV Jornadas Científicas de la AME y el XVII Encuentro Hispano Luso de Meteorología celebrado en Teruel, del 29 de febrero al 2 de marzo de 2016

    The effect of cold waves on mortality in urban and rural areas of Madrid

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    While many studies analyze the effect of extreme thermal events on health, little has been written about the effects of extreme cold on mortality. This scarcity of papers is particularly relevant when we search studies about extreme cold on the health of rural population. Therefore, we tried to analyze the effect of cold waves on urban areas and rural areas from Madrid and to test whether differentiated effects exist between both population classes. For this purpose, we analyzed data from the municipalities with over 10,000 inhabitants for the period from January 1, 2000 through December 31, 2013. Municipalities were classified as urban or rural (Eurostat), and they were grouped into similar climatological zones: Urban Metropolitan Centre (UMC), Rural Northern Mountains (RNM), Rural Centre (RC) and Southern Rural (SR). The dependent variable was the daily mortality rate due to natural causes per million inhabitants (CIE-X: A00-R99) that occurred between the months of November and March for the period. The independent variable was minimum daily temperature (ºC) (Tmin). Social and demographic contextual variables were used, including: population > age 64 (%), deprivation index and housing indicators. The analysis was carried out in three phases: (1) determination of the threshold temperature (Tthreshold) which defines the cold waves; (2) determination of the relative risk (RR) for cold waves using Poisson linear regression (GLM); and (3) using GLM of the binomial family, Odds Ratios (OR) were calculated to analyze the relationship between the frequency of the appearance of cold waves and the socioeconomic variables.The authors gratefully acknowledge the grants for projects ENPY376/18; ENPY470/19 and ENPY 107/18 from the Carlos III Institute of Health

    Does the meteorological origin of heat waves influence their impact on health? A 6-year morbidity and mortality study in Madrid (Spain)

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    In Spain, two synoptic-scale conditions influence heat wave formation. The first involves advection of warm and dry air masses carrying dust of Saharan origin. Objective: to determine whether the impact of heat waves on health outcomes in Madrid (Spain) during 2013–2018 varied by synoptic-scale condition.The authors wish to thank the funding provided by the ENPY 304/20, and ENPY 436/21 projects of the National Health Institute Carlos III (ISCIII)
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