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Quantifying baseflow and water-quality impacts from a gravel-dominated alluvial aquifer in an urban reach of a large Canadian river | Quantification du débit de base et des impacts sur la qualité de l’eau imputables à l’aquifère alluvial à prédominance graveleuse, dans la section urbaine d’une grande rivière canadienne Cuantificación del flujo de base e impactos de la calidad del agua de un acuífero aluvial dominado por gravas en un área de un sector urbano en un gran río de Canadá 一条大的加拿大河城区段砾岩主导的冲积含水层定量基流和水质影响 Quantificação dos impactos no caudal de base e na qualidade da água de um aquífero aluvial grosseiro numa extensão urbana de um grande rio do Canadá Texte intégral
2014
Cantafio, L. J. | Ryan, M. C.
Groundwater discharge and non-point source (NPS) loading were evaluated along an urban reach of an eastern-slopes Rocky Mountains river (Bow River, Canada) to understand sources of water-quality impacts and baseflow. The discharge did not increase measurably over a 16-km reach. Groundwater in the river-connected alluvial aquifer was a mixture of river and prairie groundwater, with elevated chloride concentrations (average 379 mg L–¹) from road salt. Alluvial groundwater was the major NPS of chloride discharging to the river. Although the mass-flux based estimates of groundwater discharge were small (mean 0.02 m³s–¹km–¹, SD = 0.04 m³s–¹ km–¹, n = 30), the associated chloride mass flux over 16 km was significant (equivalent to that discharged from the city’s largest wastewater-treatment-plant effluent). Although local groundwater baseflow was previously thought to contribute significantly to overwinter baseflow in this reach, little contribution was measured in this study. Low baseflow generation is consistent with long-term river discharge data that show almost all of the baseflow generation occurs in the Rocky Mountain reach. Thus, local watershed areas are important for water-quality protection, but climate change in the headwaters is most salient to long-term flow.
Afficher plus [+] Moins [-]Seasonal dynamic of a shallow freshwater lens due to irrigation in the coastal plain of Ravenna, Italy | Dynamique saisonnière d’une lentille d’eau douce sous l’effet de l’irrigationdans la plaine côtière de Ravenne, Italie Dinámica estacional de una lente somera de agua dulce debido a la irrigación enla planicie costera de Ravenna, Italia 意大利Ravenna (拉文那) 沿海平原灌溉造成的浅层淡水透镜体季节性动态变化 Dinâmica sazonal de uma lente pouco profunda de água doce devido a rega naplanície costeira de Ravenna, Itália Texte intégral
2014
Vandenbohede, Alexander | Mollema, Pauline N. | Greggio, Nicolas | Antonellini, Marco
Irrigation in low-lying coastal plains may enhance the formation of fresh groundwater lenses, which counteract salinization of groundwater and soil. This study presents seasonal dynamics of such a freshwater lens and discusses its influence on the salinity distribution of the unconfined aquifer in the coastal plain of Ravenna, Italy, combining field observations with numerical modeling (SEAWAT). The lens originates from an irrigation ditch used as a water reservoir for spray irrigation. The geometry of the freshwater lens shows seasonal differences because of freshwater infiltration during the irrigation season and upconing of deeper saltwater for the remainder of the year. The extent of the freshwater lens is controlled by the presence of nearby drainage ditches. Irrigation also results in a temperature anomaly in the aquifer because of the infiltration of warm water during the irrigation season. The surficial zone in the vicinity of the irrigation ditch is increased considerably in thickness. Finally, different irrigation alternatives and the influence of sea-level rise are simulated. This shows that it is necessary to integrate irrigation planning into the water management strategy of the coastal zone to have maximum benefits for freshening of the aquifer and to make optimal use of the existing infrastructure.
Afficher plus [+] Moins [-]Propuesta de mejoramiento del octanaje de la gasolina por la adición de hidrogeno y oxigeno mediante electrolisis del agua, para la disminución de los gases de efecto invernadero y el incremento de la combustión en un motor de combustión interna del parque automotor del cantón Latacunga Texte intégral
2014
Soria Riera, Carlos Eduardo | Ortiz, Vladimir
The rapid population growth determines the appearance of vital needs such as mobilization of people to their places of study, work, entertainment and other activities such mobilization is performed in vehicles whose operation is slowly causing damage to the nature, on this aspect is developed in this research to be analyzed and then pose as a proposal to improve the octane of gasoline by adding hydrogen and oxygen by electrolysis of water, for reducing greenhouse gases and increasing combustion in an internal combustion engine of the vehicle fleet in the canton Latacunga, the work is divided in three sections; the first chapter is determined by the problematization and general concepts fundamental to the development of this research, in the second chapter contains methodological applications made for this job and the third chapter deals with the findings, conclusions and recommendations made to achieve the success of the investigation. | El vertiginoso crecimiento de la población determina el aparecimiento de necesidades vitales como la movilización de las personas a sus centros de estudio, trabajo, entretenimiento, y demás actividades; dicha movilización se la realiza en automotores cuyo funcionamiento, poco a poco está causando deterioro a la naturaleza, sobre este aspecto se desarrolla la presente investigación en la que se pretende analizar y posteriormente plantear como propuesta el mejoramiento del octanaje de la gasolina por la adición de hidrogeno y oxigeno mediante electrolisis del agua, para la disminución de los gases de efecto invernadero y el incremento de la combustión en un motor de combustión interna del parque automotor del cantón Latacunga, el trabajo se desarrolla en tres secciones, en el primer Capítulo está determinado por la problematización y conceptos generales, fundamentales para el desenvolvimiento de esta investigación, en el segundo Capítulo consta las aplicaciones metodológicas realizadas para este trabajo y en el Tercer Capítulo trata de los resultados, conclusiones y recomendaciones efectuadas para la consecución del éxito de la investigación
Afficher plus [+] Moins [-]Funcionament del pou cisterna de la fortalesa ibera dels Vilars (les Garrigues): evidències de mesures en camp de conductivitat elèctrica de l’aigua en períodes de reg del Canal d’Urgell | Operation of the cistern well of the Iberian fortress of Els Vilars (Les Garrigues region) according to electrical conductivity measurements of water during irrigation periods of the Urgell Canal | Funcionamiento del pozo cisterna de la fortaleza íbera de Els Vilars (Les Garrigues): evidencias de medidas en campo de conductividad eléctrica del agua durante periodos de riego del Canal de Urgell Texte intégral
2014
M. Poch, Rosa | Junyent, Emili | Balasch, Carles
La fortalesa dels Vilars es caracteritza per la seva fortificació complexa i defensa activa davant del risc de setge o bloqueig en el segle iv aC. El sistema inundable de fossats assegurava el proveïment i la gestió de l’aigua, reforçava la defensa i magnificava l’arquitectura del poder. El funcionament hidrològic del sistema fossat i pou cisterna de l’interior de la fortalesa no pot derivar-se de les condicions geomorfològiques i hidrològiques actuals, pels canvis en el relleu provocats pels anivellaments causats per la posada en reg fa més de cent anys, i, també, pel mateix regatge que ha modificat la dinàmica de la capa freàtica de la zona. Malgrat això, l’existència d’una capa freàtica artificial provocada pel reg permet estudiar la connexió entre les aigües d’escolament del torrent de l’Aixaragall —que suposadament alimentava el fossat— i les del pou cisterna. Mesures de conductivitat elèctrica de l’aigua en els diversos sistemes en tres moments corresponents a dues campanyes de reg (2012 i 2013) suggereixen una connexió entre la capa superficial de l’aqüitard format per les calcilutites oligocenes subjacents al fossat, les graves quaternàries que formen el con de dejecció del torrent de l’Aixaragall i el pou. En conseqüència, les mesures preses són compatibles amb l’alimentació del pou a partir del fossat inundat, i amb un origen superficial de l’aigua que devia omplir-lo procedent del torrent de l’Aixaragall.Paraules clau: arqueologia, hidrologia de pous, salinitat, fossat inundat, fortalesa dels Vilars. | The 4th c. BCE fortress of Els Vilars is marked by its complex fortification and its conception of active defence against the risk of siege or blockade. Its system of floodable moats assured its water supply and management, strengthened its defence and accentuated its architecture of power. The hydrological operation of the exterior moat-interior cistern well system could not be elucidated on the basis of today’s geomorphological and hydrological conditions because of the levelling of the surrounding topography since the advent of its irrigation over 100 years ago and because irrigation itself has changed the dynamics of the area’s water table. Despite this, the existence of an artificial water table produced by irrigation allows the study of the connection between the water runoff from the Aixaragall torrent, which supposedly fed the moat, and the water in the cistern well. Electrical conductivity measurements of the water in the various systems at three different moments in the course of two irrigation campaigns (2012 and 2013) suggest a connection between the surface layer of the aquitard formed by Oligocene calcilutites underlying the moat, the Quaternary gravels of the Aixaragall torrent’s alluvial fan and the cistern well. Consequently, the measurements recorded are consistent with the supply of the well from the flooded moat and with the supply of the moat by surface water from the Aixaragall torrent.Keywords: archaeology, well hydrology, salinity, flooded moat, fortress of Els Vilars. | La fortaleza de Els Vilars se caracteriza por su fortificación compleja y defensa activa frente al riesgo de asedio o bloqueo en el siglo iv aC. El sistema inundable de los fosos aseguraba el abastecimiento y la gestión del agua, reforzaba la defensa y magnificaba la arquitectura del poder. El funcionamiento hidrológico del sistema foso y pozo cisterna del interior de la fortaleza no puede derivarse de las condiciones geomorfológicas e hidrológicas actuales, debido a los cambios en el relieve provocados por nivelaciones causadas por la puesta en riego hace más de cien años, y al propio riego que ha modificado la dinámica de la capa freática de la zona. A pesar de ello, la existencia de una capa freática provocada por riego permite estudiar la conexión entre las aguas de escorrentía del torrente del Aixaragall —que supuestamente alimentaba el foso— y las del pozo cisterna. Medidas de conductividad eléctrica del agua en los diversos sistemas en tres momentos correspondientes a dos campañas de riego (2012 y 2013) sugieren una conexión entre la capa superficial del acuitardo formado por las calcilutitas oligocenas subyacentes en el foso, las gravas cuaternarias que forman el cono de deyección del torrente del Aixaragall y el pozo. En consecuencia, las medidas tomadas son compatibles con la alimentación del pozo a partir del foso inundado, y con un origen superficial del agua que debía llenarlo a partir del torrente del Aixaragall.Palabras clave: arqueología, hidrología de pozos, salinidad, foso inundado, fortaleza de Els Vilars.
Afficher plus [+] Moins [-]Site selection for drinking-water pumping boreholes using a fuzzy spatial decision support system in the Korinthia prefecture, SE Greece | Sélection de site pour des forages de pompage d’eau potable utilisant un système spatiald’aide à la décision basée sur la logique floue, appliqué à la préfecture de Corinthe, SE Grèce Selección del sitio para perforaciones de bombeo de agua potable usando un sistema de apoyode decisión espacial difusa en la prefectura de Korinthia, SE de Grecia 采用模糊空间决策支持系统选择希腊东南部Korinthia地区饮用水抽水井场地 Επιλογή κατάλληλων θέσων για ανόρυξη υδρογεωτρήσεων με χρήση ασαφούς λογικής καιενός χωρικού συστήματος υποστήριξης αποφάσεων στην Κορινθία, ΝΑ Ελλάδα Seleção do local para poços de bombeamento de água potável através de um sistema de apoioà decisão espacial difusa no município de Korinthia, SE da Grécia Texte intégral
2014
Antonakos, Andreas K. | Voudouris, Konstantinos S. | Lambrakis, Nikolaos I.
The implementation of a geographic information system (GIS)/fuzzy spatial decision support system in the selection of sites for drinking-water pumping boreholes is described. Groundwater is the main source of domestic supply and irrigation in Korinthia prefecture, south-eastern Greece. Water demand has increased considerably over the last 30 years and is mainly met by groundwater abstracted via numerous wells and boreholes. The definition of the most “suitable” site for the drilling of new boreholes is a major issue in this area. A method of allocating suitable locations has been developed based on multicriteria analysis and fuzzy logic. Twelve parameters were finally involved in the model, prearranged into three categories: borehole yield, groundwater quality, and economic and technical constraints. GIS was used to create a classification map of the research area, based on the suitability of each point for the placement of new borehole fields. The coastal part of the study area is completely unsuitable, whereas high values of suitability are recorded in the south-western part. The study demonstrated that the method of multicriteria analysis in combination with fuzzy logic is a useful tool for selecting the best sites for new borehole drilling on a regional scale. The results could be used by local authorities and decision-makers for integrated groundwater resources management.
Afficher plus [+] Moins [-]Evaluation of Escherichia coli concentrations in Crassostrea gigas and seawater in two oyster growing areas in the Gulf of Nicoya, Costa Rica | Evaluación de las concentraciones de Escherichia coli en Crassostrea gigas y agua de mar en dos zonas de cultivo de ostras ubicadas en el Golfo de Nicoya, Costa Rica Texte intégral
2014
Vega-Corrales, Luis | Marín, Carolina
Costa Rica does not have references on the health quality of Crassostrea gigas growing areas, which can pose a po tential public health risk. This study evaluated the temporal trends of Escherichia coli concentrations in the C. gigas oyster and in the seawater of Punta Cuchillo and Punta Morales growing areas as a basis for the classification and monitoring of bivalve mollusc production sites in the Gulf of Nicoya, Costa Rica. Monthly samples of seawater and C. gigas were collected from each site from July 2011 to June 2012, and their levels of E. coli were determined using the most probable number method. Temperature and salinity were recorded at a one meter depth. Precipitation data was provided by Instituto Meteorológico Nacional (the National Meteorological Institute). Results indicated that the evaluated areas are probably being affected by wastewater discharge. Punta Cuchillo and Punta Morales could be classified as class A or authorized areas for the production of bivalve molluscs. A significant seasonal variability of E. coli concentrations was determined in seawater and oysters from the Gulf of Nicoya, defined primarily by salinity. National legislation should be created to establish controls and implement a monitoring system ensuring the bacteriological quality of the areas used for the cultivation of bivalve molluscs in the country. | Costa Rica no cuenta con referencias sobre la calidad sanitaria de las zonas de cultivo de Crassostrea gigas y esto puede representar un riesgo para la salud pública. Se evaluó la tendencia temporal de las concentraciones de Escherichia coli en la ostra C. gigas y en el agua de mar de las zonas de cultivo de Punta Cuchillo y de Punta Morales como base para la clasificación y la vigilancia de los sitios de producción de moluscos bivalvos en el Golfo de Nicoya, Costa Rica. Muestras mensuales de agua de mar y de C. gigas de cada zona fueron recolectadas de julio de 2011 a junio de 2012 y se les determinó los niveles de E. coli por la técnica del número más probable. La temperatura y la salinidad fueron registradas a un metro de profundidad. Los datos de precipitación fueron suministrados por el Instituto Meteorológico Nacional. Los resultados indicaron que las áreas evaluadas podrían estar siendo afectadas por el vertido de aguas residuales. Punta Cuchillo y Punta Morales podrían clasificarse como zonas autorizadas o tipo A para la producción de moluscos bivalvos. Se determinó una variabilidad estacional significativa de las concentraciones de E. coli en agua de mar y en ostras del Golfo de Nicoya, definida principalmente por la salinidad. Se debe generar una normativa nacional que establezca controles e implemente un sistema de vigilancia que asegure la calidad bacteriológica de las áreas destinadas para el cultivo de moluscos bivalvos en el país. | Universidad Nacional, Costa Rica | Escuela de Ciencias Biológicas
Afficher plus [+] Moins [-]Evaluation of Escherichia coli concentrations in Crassostrea gigas and seawater in two oyster growing areas in the Gulf of Nicoya, Costa Rica | Evaluación de las concentraciones de Escherichia coli en Crassostrea gigas y agua de mar en dos zonas de cultivo de ostras ubicadas en el Golfo de Nicoya, Costa Rica Texte intégral
2014
Vega Corrales, Luis A. | Marín-Vindas, Carolina
12 pages, 4 figures, 3 tables | [EN] Costa Rica does not have references on the health quality of Crassostrea gigas growing areas, which can pose a potential public health risk. This study evaluated the temporal trends of Escherichia coli concentrations in the C. gigas oyster and in the seawater of Punta Cuchillo and Punta Morales growing areas as a basis for the classification and monitoring of bivalve mollusc production sites in the Gulf of Nicoya, Costa Rica. Monthly samples of seawater and C. gigas were collected from each site from July 2011 to June 2012, and their levels of E. coli were determined using the most probable number method. Temperature and salinity were recorded at a one meter depth. Precipitation data was provided by Instituto Meteorológico Nacional (the National Meteorological Institute). Results indicated that the evaluated areas are probably being affected by wastewater discharge. Punta Cuchillo and Punta Morales could be classified as class A or authorized areas for the production of bivalve molluscs. A significant seasonal variability of E. coli concentrations was determined in seawater and oysters from the Gulf of Nicoya, defined primarily by salinity. National legislation should be created to establish controls and implement a monitoring system ensuring the bacteriological quality of the areas used for the cultivation of bivalve molluscs in the country | [ES] Costa Rica no cuenta con referencias sobre la calidad sanitaria de las zonas de cultivo de Crassostrea gigas y esto puede representar un riesgo para la salud pública. Se evaluó la tendencia temporal de las concentraciones de Escherichia coli en la ostra C. gigas y en el agua de mar de las zonas de cultivo de Punta Cuchillo y de Punta Morales como base para la clasificación y la vigilancia de los sitios de producción de moluscos bivalvos en el Golfo de Nicoya, Costa Rica. Muestras mensuales de agua de mar y de C. gigas de cada zona fueron recolectadas de julio de 2011 a junio de 2012 y se les determinó los niveles de E. coli por la técnica del número más probable. La temperatura y la salinidad fueron registradas a un metro de profundidad. Los datos de precipitación fueron suministrados por el Instituto Meteorológico Nacional. Los resultados indicaron que las áreas evaluadas podrían estar siendo afectadas por el vertido de aguas residuales. Punta Cuchillo y Punta Morales podrían clasificarse como zonas autorizadas o tipo A para la producción de moluscos bivalvos. Se determinó una variabilidad estacional significativa de las concentraciones de E. coli en agua de mar y en ostras del Golfo de Nicoya, definida principalmente por la salinidad. Se debe generar una normativa nacional que establezca controles e implemente un sistema de vigilancia que asegure la calidad bacteriológica de las áreas destinadas para el cultivo de moluscos bivalvos en el país | Peer Reviewed
Afficher plus [+] Moins [-]Taller de la Region Sudasi?tica sobre Sistemas de Riego con Aguas Subterr?neas Administrados por los Agricultores y el Manejo Sustentable del Agua Subterr?nea Dhaka, Bangladesh 18-21 de mayo de 1992South Asian Regional Workshop on Groundwater Farmer-Managed Irrigation Systems and Sustainable Groundwater Management, Dhaka, Bangladesh 18-21 May 1992 Texte intégral
2014
s. manor | ramaswamy sakthivadivel | d. parker
Ramaswamy Sakthivadivel, D. Parker, S. Manor, 'Taller de la Region Sudasi?tica sobre Sistemas de Riego con Aguas Subterr?neas Administrados por los Agricultores y el Manejo Sustentable del Agua Subterr?nea Dhaka, Bangladesh 18-21 de mayo de 1992South Asian Regional Workshop on Groundwater Farmer-Managed Irrigation Systems and Sustainable Groundwater Management, Dhaka, Bangladesh 18-21 May 1992', FMIS Newsletter, 2014
Afficher plus [+] Moins [-]Groundwater flow and its effect on salt dissolution in Gypsum Canyon watershed, Paradox Basin, southeast Utah, USA | Ecoulements d’eau souterraine et leur effet sur la dissolution du sel dans le bassin gypsifère du Canyon, Bassin du Paradox, Sud Est de l’Utah, Etats Unis d’Amérique Flujo de agua subterránea y su efecto en la disolución de sales en la cuenca de Gypsum Canyon, Paradox Basin, sudeste de Utah, EEUU 美国犹他州东南部Paradox盆地Gypsum Canyon流域的地下水流及其对盐类溶解的影响 O fluxo de água subterrânea e o seu efeito sobre a dissolução de sais na sub-bacia hidrográfica de Gypsum Canyon, Bacia de Paradox, no sudeste de Utah, EUA Texte intégral
2014
Reitman, Nadine G. | Ge, Shemin | Mueller, Karl
Groundwater flow is an important control on subsurface evaporite (salt) dissolution. Salt dissolution can drive faulting and associated subsidence on the land surface and increase salinity in groundwater. This study aims to understand the groundwater flow system of Gypsum Canyon watershed in the Paradox Basin, Utah, USA, and whether or not groundwater-driven dissolution affects surface deformation. The work characterizes the groundwater flow and solute transport systems of the watershed using a three-dimensional (3D) finite element flow and transport model, SUTRA. Spring samples were analyzed for stable isotopes of water and total dissolved solids. Spring water and hydraulic conductivity data provide constraints for model parameters. Model results indicate that regional groundwater flow is to the northwest towards the Colorado River, and shallow flow systems are influenced by topography. The low permeability obtained from laboratory tests is inconsistent with field observed discharges, supporting the notion that fracture permeability plays a significant role in controlling groundwater flow. Model output implies that groundwater-driven dissolution is small on average, and cannot account for volume changes in the evaporite deposits that could cause surface deformation, but it is speculated that dissolution may be highly localized and/or weaken evaporite deposits, and could lead to surface deformation over time.
Afficher plus [+] Moins [-]The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling | Le Système Aquifère Nubien fossile transfrontalier du Tchad, de l’Egypte, de la Lybie et du Soudan: questions classiques de nappe souterraine, analyse hydrogéologique simplifiée et modélisation El Sistema Acuífero Nubio transfronterizo no renovable en Chad, Egipto, Libia y Sudan: problemas clásicos de agua subterránea y el escaso análisis y modelado hidrogeológico 乍得、埃及、利比亚和苏丹跨国界不可更新的努比亚含水层系统:典型的地下水问题和简单的水文地质分析和模 O Sistema Aquífero transfronteiriço não renovável Núbio do Chade, Egito, Líbia e Sudão: problemas clássicos de água subterrânea, análise hidrogeológica parcimoniosa e modelação Texte intégral
2014
Voss, Clifford I. | Soliman, Safaa M.
Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world’s largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.
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