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Elevación máxima del agua en la laguna Mar Chiquita, Córdoba, Argentina Texto completo
2014
Pagot, Mariana(Universidad Nacional de Córdoba Facultad de Ciencias Exactas, Físicas y Naturales Laboratorio de Hidráulica) | Hillman, Gerardo | Pozzi-Piacenza, Cecilia | Gyssels, Paolo | Patalano, Antoine | Rodriguez, Andrés
La laguna Mar Chiquita es el mayor cuerpo de agua endorreico de la República Argentina y está ubicada al noreste de la provincia de Córdoba. El nivel de agua máximo es objeto de este trabajo y se definió con base en el efecto combinado del máximo nivel de agua histórico medido sobre la costa sur y de la máxima sobre-elevación por tormenta estimado para recurrencias de 25, 50 y 100 años. El análisis de las series de niveles de agua permitió definir el valor máximo histórico del nivel medido en la laguna. Este valor se registró en el año 2003 con una cota de 71.9 m sobre nivel del mar (snm). La máxima sobre-elevación por tormenta se definió por la acción conjunta del viento y del oleaje generado por el mismo. Para estas estimaciones se utilizaron programas específicos y formulaciones empíricas. Para propagar el oleaje sobre el perfil de playa, se reconstruyó la batimetría de la laguna, basada en técnicas de teledetección. A tal efecto se utilizaron datos de elevación del terreno, tomando relevamientos espaciales con radar y mapas temáticos derivados de imágenes satelitales ópticas, productos LandSat, basados en el proceso de extracción digital de los contornos de agua. Los resultados indicaron que la cota máxima de inundación de la laguna Mar Chiquita para la costa sur del sistema podría llegar a los 73.5 msnm para una recurrencia de 100 años. Este análisis es importante realizarlo en sistemas que presentan grandes fluctuaciones del nivel de agua, como el aquí presentado. | Mar Chiquita lagoon is the largest endorheic body of water in Argentina. It is located in the northeast portion of the province of Cordoba. The maximum water level is the topic of this work, which is defined using the combined effect of the historical maximum water level measured on the coast and the maximum storm elevation (considering both wind and waves) estimated for recurrences of 25, 50 and 100 years. The analysis of the series of water levels made it possible to determine the historical maximum level measured in the lagoon. This value was recorded in 2003 as a height of 71.9 meters above sea level (masl). The maximum storm level is defined by both the action of the wind and waves generated by the storm. Specific software and empirical formulas were used to obtain these estimates. To propagate the waves on the beach profile, the bathymetry of the lagoon was rebuilt using remote sensing techniques. To this end, terrain elevation data were used from space surveys derived from radar and from thematic maps based on Landsat images with the digital extraction of water contours. The results indicate that the maximum flood that could occur in Laguna Mar Chiquita, on the southern coast of the system, is 73.5 masl with a recurrence of 100 years. It is important to conduct this analysis for systems with large fluctuations in water levels, such as the one presented here.
Mostrar más [+] Menos [-]Modelagem das perdas de água por evaporação e arraste em aspersores de média pressão Texto completo
2011
Beskow, Samuel(UFPel CDTec) | Faria, Lessandro C.(UFLA DEG) | Colombo, Alberto(UFLA DEG) | Moura, Débora C. M. de
Five empirical models were evaluated with respect to their ability to estimate evaporation and wind drift losses of Agropolo/NY (nozzle 3.5 mm) and Naan/5024 (nozzle 3.0 mm) sprinklers, and other specific models were developed for each sprinkler model. By comparing measured results, which were obtained in field trials, with simulated ones (models of Yazar, 1984; Trimmer, 1987; Seginer et al., 1991; Tarjuelo et al., 2000; and Playán et al., 2005), these models were classified as very bad or poor according to the index of performance. However, the new adjusted models presented lower errors, resulting in indexes of performance classified as good and very good, thus indicating that their application must be limited to operational conditions (nozzle size, operational pressure, etc.) similar to those in which they were developed. | Neste estudo se avaliou a capacidade preditiva de cinco modelos empíricos visando estimar as perdas de água por evaporação e arraste dos aspersores Agropolo/NY (bocal 3,5 mm) e Naan/5024 (bocal 3,0 mm); para cada aspersor foram ajustados modelos específicos. Por meio de comparação entre resultados de distribuição de água medidos em ensaios de campo e resultados simulados com os modelos propostos por Yazar (1984), Trimmer (1987), Seginer et al. (1991), Tarjuelo et al. (2000) e Playán et al. (2005) foi possível concluir que os diferentes modelos considerados apresentaram índices de desempenho classificado como Péssimo ou, no máximo, Sofrível. Comparados com os cinco modelos empíricos considerados, os novos modelos ajustados apresentaram menores erros, qualificando-se para serem utilizados com índices de desempenho classificado como Bom e Muito Bom, indicando que a aplicação de modelos empíricos deve ser limitada ás condições operacionais (diâmetro de bocal, pressão de operação, etc.) similares áquelas em que os modelos foram desenvolvidos.
Mostrar más [+] Menos [-]Efecto del viento en el coeficiente de atenuación de la luz en el agua para el saco interno de la Bahia de Cádiz | The influence of wind velocity on water column light attenuation coefficients within the inner Bay of Cádiz Texto completo
García-San-Miguel-Barreiro, Carmen | Peralta González, Gloria | Morris, Edward P. | Biología
Over 90 % of Cádiz Inner Bay, a shallow (3 m MLW), tidal lagoon, is inhabited by benthic macrophytes. The survival and productivity of these populations, and therefore their role in the ecosystem, strongly depends on the availability of light. Thus, to understand the ecology of benthic macrophytes within the bay it is fundamentally important to know how which factors affect benthic light availability. In this study, we analysed a historical database of benthic light availability (2006 - 2010), revealing strong evidence for a relation between wind and attenuation of light in the water column. Furthermore, 4 deployments of in situ measurements, carried out under different wind conditions, were examined so as to provide indications as to the mechanisms involved in the interaction between wind and light attenuation. The results demonstrate a clear relationship between the magnitude and direction of the wind and the attenuation of light. Waves generate higher orbital velocities at the sediment surface, presumably enhancing resuspension, which in turn, significantly affects the concentration of suspended solids in the water column and the water column attenuation coefficient. In conclusion, wind-wave generation and the subsequent resuspension of sediments appear to be one of the important mechanisms controlling light availability within Cadiz Inner Bay. | Proyecto de investigación de excelencia FUNDIV (P07-RNM-02516), cofinanciado por la Junta de Andalucía y la Unión Europea (fondos FEDER) y gracias al proyecto nacional iMACHIDRO (CTM2008-00012/MAR), cofinanciado por el Ministerio de Ciencia y Tecnología y la Unión Europea (fondos FEDER).
Mostrar más [+] Menos [-]Influência de fatores climáticos e operacionais sobre a uniformidade de distribuição de água, em um sistema de irrigação por aspersão de alta pressão Texto completo
2000
Azevedo, Hamilton Jorge(UFRRJ) | Bernardo, Salassier(UENF CCTA) | Ramos, Marcio Mota(UFV Depto. Engenharia Agrícola) | Sediyama, Gilberto Chohaku(UFV Depto. Engenharia Agrícola) | Cecon, Paulo Roberto(UFV Depto. de Estatística e Informática)
Realizou-se um estudo para se avaliar a uniformidade de distribuição de água em um sistema de irrigação por aspersão de alta pressão, na região norte-fluminense, RJ. Por meio da metodologia descrita pela ASAE (1990) foi avaliada a uniformidade de distribuição de água utilizando-se, para isso, o coeficiente de uniformidade de Christiansen (CUC) com aspersores em disposição retangular e triangular. Para cada uma das situações, o CUC foi analisado em função das seguintes variáveis independentes: velocidade e direção do vento, pressão de operação do aspersor, espaçamento entre aspersores na linha lateral, espaçamento entre linhas laterais e velocidade de rotação do aspersor. A análise dos dados foi feita por meio de regressão múltipla, gerando-se modelos estatísticos para a estimativa do CUC. Observou-se que o aumento da velocidade do vento e do espaçamento entre aspersores diminui o CUC, enquanto o aumento da pressão de operação do aspersor o elevou nos intervalos estudados. | A study was performed to evaluate the water distribution uniformity in a high pressure sprinkle system in the norte-fluminense region, RJ. The field experiment was carried out according to ASAE (1990) methodology. Christiansen uniformity coefficient (CUC) was used to evaluate the water application distribution uniformity, with sprinklers placed in rectangular and triangular spacings. For each one of these situations the CUC was analysed according to the following independent variables: wind speed and direction, operation pressure, spacings between sprinklers and lateral lines, and sprinkler speed rotation. The evaluation of data was made with multiple regression analysis, which made it possible to develop a statistical model to estimate the CUC. It was observed that the increase in wind speed and spacing between sprinklers reduced the CUC, while the increase in sprinkler pressure increased the CUC.
Mostrar más [+] Menos [-]Modelagem das perdas de água por evaporação e arraste em aspersores de média pressão Modeling of evaporation and wind drift losses in medium-pressure sprinklers Texto completo
2011
Samuel Beskow | Lessandro C. Faria | Alberto Colombo | Débora C. M. de Moura
Neste estudo se avaliou a capacidade preditiva de cinco modelos empíricos visando estimar as perdas de água por evaporação e arraste dos aspersores Agropolo/NY (bocal 3,5 mm) e Naan/5024 (bocal 3,0 mm); para cada aspersor foram ajustados modelos específicos. Por meio de comparação entre resultados de distribuição de água medidos em ensaios de campo e resultados simulados com os modelos propostos por Yazar (1984), Trimmer (1987), Seginer et al. (1991), Tarjuelo et al. (2000) e Playán et al. (2005) foi possível concluir que os diferentes modelos considerados apresentaram índices de desempenho classificado como Péssimo ou, no máximo, Sofrível. Comparados com os cinco modelos empíricos considerados, os novos modelos ajustados apresentaram menores erros, qualificando-se para serem utilizados com índices de desempenho classificado como Bom e Muito Bom, indicando que a aplicação de modelos empíricos deve ser limitada ás condições operacionais (diâmetro de bocal, pressão de operação, etc.) similares áquelas em que os modelos foram desenvolvidos.<br>Five empirical models were evaluated with respect to their ability to estimate evaporation and wind drift losses of Agropolo/NY (nozzle 3.5 mm) and Naan/5024 (nozzle 3.0 mm) sprinklers, and other specific models were developed for each sprinkler model. By comparing measured results, which were obtained in field trials, with simulated ones (models of Yazar, 1984; Trimmer, 1987; Seginer et al., 1991; Tarjuelo et al., 2000; and Playán et al., 2005), these models were classified as very bad or poor according to the index of performance. However, the new adjusted models presented lower errors, resulting in indexes of performance classified as good and very good, thus indicating that their application must be limited to operational conditions (nozzle size, operational pressure, etc.) similar to those in which they were developed.
Mostrar más [+] Menos [-]Building Resilience : Integrating Climate and Disaster Risk into Development | Crear resiliencia mediante la integración de los riesgos climáticos y de desastre en el proceso de desarrollo - Resumen ejecutivo (Vol. 2) | Renforcement de la résistance aux chocs climatiques : Intégrer la dimension climatique et les risques de catastrophes dans les plans de développement - Les leçons de l’expérience du Groupe de la Banque mondiale | Caudal : revista sectorial de agua y saneamiento - Bolivia | Promouvoir la bonne gouvernance par les fonds sociaux et la d?ntralisation Texto completo
2013
World Bank
This report presents the World Bank Group's experience in climate and disaster resilient development and contends that it is essential to eliminate extreme poverty and achieve shared prosperity by 2030. The report argues for closer collaboration between the climate resilience and disaster risk management communities through the incorporation of climate and disaster resilience into broader development processes. Selected case studies are used to illustrate promising approaches, lessons learned, and remaining challenges all in contribution to the loss and damage discussions under the United Nations Framework Convention on Climate Change (UNFCCC). The introduction provides an overview of the UNFCCC and also introduces key concepts and definitions relevant to climate and disaster resilient development. Section two describes the impacts of globally increasing weather-related disasters in recent decades. Section three summarizes how the World Bank Group's goals to end extreme poverty and boost shared prosperity are expected to be affected by rising disaster losses in a changing climate. Section four discusses the issue of attribution in weather-related disasters, and the additional start-up costs involved in climate and disaster resilient development. Section five builds upon the processes and instruments developed by the climate resilience and the disaster risk management communities of practice to provide some early lessons learned in this increasingly merging field. Section six highlights case studies and emerging good practices in climate and disaster resilient development. Section seven concludes the report, summarizing key lessons learned and identifying potential gaps and avenues for future work. | En el informe “Crear resiliencia mediante la integración de los riesgos climáticos y de desastre en el proceso de desarrollo” se muestra por qué es esencial desarrollar la resiliencia al clima para poder alcanzar los objetivos del Grupo del Banco Mundial de poner fin a la pobreza extrema y promover la prosperidad compartida. En este resumen ejecutivo se hace un llamado a la comunidad internacional del desarrollo a trabajar en diversas disciplinas y sectores con el propósito de generar una mayor resiliencia de largo plazo, reducir los riesgos y evitar mayores costos en el futuro. Se hace hincapié en la necesidad de crear instituciones y dotarlas de los medios para emprender la continua labor que se requiere para lograr un desarrollo en que se tenga en cuenta la resiliencia al clima y a los desastres. Al destacar las mejores prácticas, el informe muestra cómo los instrumentos financieros y los programas de intervención, sumados a la experiencia y conocimientos especializados en preparación para casos de desastre adquiridos durante décadas, están ayudando a las naciones a prepararse para un mundo más expuesto a los cambios. Asimismo, en el informe se reconoce que un desarrollo con tales características tiene costos iniciales adicionales, que se amortizan en el largo plazo si se actúa correctamente. En este contexto, el informe propugna una colaboración más estrecha entre las comunidades responsables de crear resiliencia al clima y las encargadas de administrar los riesgos de desastre, y la incorporación de la resiliencia al clima y a los desastres en los procesos de desarrollo en sentido más amplio. Presenta estudios de casos seleccionados para mostrar algunos enfoques promisorios, las lecciones aprendidas y los desafíos que aún existen. | Le présent rapport explique pourquoi le renforcement de la résistance aux chocs climatiques est une condition essentielle à la réalisation des objectifs du Groupe de la Banque mondiale — mettre fin à la pauvreté extrême et promouvoir une prospérité partagée — et pourquoi il devrait constituer la clé de voûte du programme mondial de développement. À défaut d’aider les pays, les régions et les villes pauvres et vulnérables à se préparer et à s’adapter aux risques climatiques actuels et futurs, nous risquons de mettre en péril des décennies d’acquis du développement. Nous espérons que ce rapport, en s’appuyant sur l’expérience de la Banque mondiale en matière de résistance aux chocs climatiques et de préparation aux catastrophes naturelles, contribuera utilement au débat international en cours sur les moyens de lutte contre les pertes et les dommages occasionnés par le changement climatique. Le rapport reconnaît cependant qu’un tel développement exige au départ des financements supplémentaires qui s’avéreront rentables à long terme si les choses sont faites correctement. Dans ce contexte, le rapport préconise un renforcement de la collaboration entre les collectivités engagées dans l’application de mesures de résistance aux chocs climatiques et de gestion des risques de catastrophe, ainsi que l’intégration de ces mesures dans le cadre plus large de leurs processus de développement. Le rapport s’appuie sur diverses études de cas pour illustrer les démarches prometteuses, les enseignements tirés de l’expérience et les difficultés qui restent à surmonter. Le rapport entend contribuer au débat engagé dans le cadre de la Convention-cadre des Nations Unies sur les changements climatiques au sujet des pertes et des préjudices liés aux effets néfastes des changements climatiques. Il s’adresse principalement aux professionnels du développement et aux décideurs nationaux qui doivent composer avec le défi posé par une aggravation possible des catastrophes causées par l’évolution graduelle des conditions climatiques moyennes et extrêmes.
Mostrar más [+] Menos [-]Source of saline groundwater on tidally influenced blue holes on San Salvador Island, Bahamas | Origine de l’eau souterraine salée dans les trous bleus influencés par les marées sur l’île de San Salvador aux Bahamas Origen de las aguas subterráneas salinas con influencia de las mareas en los pozos de agua dulce de la isla de San Salvador (Bahamas) 受潮汐影响的Bahamas的San Salvador岛蓝洞上的地下咸水来源 Origem de águas subterrâneas salinas em orifícios azuis influenciados pela maré na ilha de San Salvador, Bahamas Sursa apei saline din găurile albastre afectate de maree de pe Insula San Salvador, Bahamas Texto completo
2021
Smith, Megan E. | Wynn, Jonathan G. | Scharping, Robert J. | Moore, Evan W. | Garey, James R. | Onac, Bogdan P.
Stable hydrogen and oxygen isotope signatures of waters within Church and Inkwell blue holes are measured on San Salvador Island (Bahamas) to identify the origin of their fresh and saline waters. Stable isotope data, paired with a suite of physicochemical water parameters measured throughout the blue holes, as a function of both time and depth, provide a detailed understanding of the tidally influenced groundwater interactions on the island. Blue holes are prominent karst features in carbonate environments which serve as windows into subterranean hydrologic processes. Carbonate island hydrology is often complicated by complex interactions between the marine and meteoric water systems, as tidal pumping and water mixing result in diagenetic alteration of the bedrock, that in turn influence dissolution rates and preferential flow paths. Although the blue holes on the island are physically influenced by tidal forcing, the stable isotope data indicate that both their fresh and saline waters are of a meteoric origin rather than seawater, where the meteoric water is likely becoming saline through enrichment by aerosol-derived sea salts. Additionally, the physical profiles of each blue hole indicate differences in mixing processes driven by wind and tidal forcing, where stronger mixing can result in a disruption of the freshwater lens. The implications of this study are important for assessing mixing corrosion processes and dissolution effects, but more research and longer data sets are needed to show whether these results are applicable to other coastal carbonate environments.
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