855 resultados para dam impacts
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In this paper a comparative analysis of the environmental impact caused by the use of natural gas and diesel in thermoelectric power plants utilizing combined cycle is performed. The objective is to apply a thermoeconomical analysis in order to compare the two proposed fuels. In this analysis, a new methodology that incorporates the economical engineering concept to the ecological efficiency once Cardu and Baica [1, 2], which evaluates, in general terms, the environmental impacts caused by CO2, SO2, NOx and Particulate Matter (PM), adopting as reference the air quality standards in vigour is employed. The thermoeconomic model herein proposed utilizes functional diagrams that allow the minimization the Exergetic Manufacturing Cost, which represents the cost of production of electricity incorporating the environmental impact effects to study the performance of the thermoelectric power plant [3,4], It follows that it is possible to determine the environmental impact caused by thermoelectric power plants and, under the ecological standpoint, the use of natural gas as a fuel is the best option compared to the use of the diesel, presenting ecological efficiency values of 0.944 and 0.914 respectively. From the Exergoeconomic point of view of, it was found out that the EMC (Exergetic Manufacturing Cost) is better when natural gas is used as fuel compared to the diesel fuel. Copyright © 2006 by ASME.
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The purpose of this study was to develop a methodology for evaluating neighborhood impacts using a Geographic Information System (GIS) and to apply the procedures to the companies of the High-Technology Industrial Cluster of São Carlos. To this end, an evaluation was made of the neighborhood impacts on the physical environment, urban components, quality of life, and urban infrastructure using impact matrices, and the impacts were assigned scores according to type, order, magnitude and duration. Fifty one companies were examined based on data provided by the companies themselves and on field surveys. The impacts are represented spatially in proportional symbols maps, based on the spatial distribution of the companies in the urban area of the city of São Carlos and the areas of influence of each company. The application of the proposed methodology served to validate it and indicated that the neighborhood impacts caused by the companies of this study are related to each company's type of activity, its size, and its occupation of the area. © 2008 Journal of Urban and Environmental Engineering (JUEE). All rights reserved.
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The proposal and implementation of parceling real estate into smaller lots in Brazil is done according to legal and technical formalities. However, these instruments have proved inefficient in reducing the resulting environmental impacts. The ambiguities of the federal, state and municipal laws and regulations have limited the effectiveness of the actions of urban administrators. Law 10257/2001 emerged as an alternative to overcome these difficulties, proposing the adoption of neighborhood impact studies as an instrument to evaluate new proposals of urban occupation for purposes of environmental licensing. Thus, the purpose of this law is to provide the foundations for municipal public authorities to establish criteria for the assessment, mitigation and compensation of impacts resulting from new occupations. However, the very vagueness of the generic nature of this federal law and its incorrect application in the municipal sphere has posed the greatest obstacles to the good use of this instrument of urban environmental management. These deficiencies are classified herein in the categories of philosophical, technical and operational problems. The problems of a philosophical nature lead to technical difficulties, which in turn trigger operational deficiencies. This article discusses these deficiencies and points out ways to reduce them. © 2009 Journal of Urban and Environmental Engineering (JUEE). All rights reserved.
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Includes bibliography.
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Includes bibliography.
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This paper attempts to assess both the touristic potential of scenic attractions and the environmental impacts resulting from the public use of such attractions in the Rifaina Municipality, State of São Paulo, Southeastern Brazil. In the recent past, this municipality had its economy concentrated in rural activities (livestock, corn, rice and bean crops) and in the ceramic industry (production of bricks, tiles and shackles),which was largely developed in the floodplain of the Rio Grande before the construction of the Jaguara Power Plant Dam. The impacts resulting from touristic activities were evaluated by applying the VIM - Visitor Impact Management method, with emphasis on biophysical indicators. The main touristic attractions analyzed were: (1) Rifaina artificial beach; (2) Jaguara Reservoir; (3) Morro do Chapéu (scenic hill); (4) Touristic railroad; and (5) Cuestas cliffs. Attractions (1) and (2) are the most exploited ones, including, in the second case, nautical sports, sportive and craft fishing, and summer lodging. Although currently disabled, the touristic railroad presents potential conditions to be re-explored. Attractions (3) and (5), despite keeping high landscape and ecological ecotouristic potential, are the least visited places. In the present paper, a preliminary characterization of the major issues of tourism industry in the Rifaina municipality is made, including suggestions for the sustainable exploitation of tourism resources. The final results of the environmental impact evaluation of the tourism activities include small impacts in attractions (4) and (5) and moderate impacts to the three first attractions. In order to keep the sustainable touristic potential for that municipality this study proposes the improvement of the following measures: to foster research projects on technical or scientific aspects of the touristic attractions, improvement of tourism infrastructure and the creation of an Environmental Protection Area (APA) of the cuestas' scarps.
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To evaluate the effects of distinct management of the matrix in which forest fragments are found upon plant populations thriving in forest remnants in south Brazil, we assessed the conservation status of populations of four woody species (Campomanesia rhombea, Diospyros incontans, Myrciaria cuspidata and Sebastiania commersoniana) through analyses of size structure. Analyzes were carried out at two scales. At a local scale, we consider populations in fragments surrounded by pastures or eucalypts forest plantations, and at a regional scale we also consider larger forest tracts taken as reference areas (Rio Grande do Sul Forest Inventory databank). Population size structures were summarized using the symmetry of height distributions. Small individual size classes prevailed at the local scale in fragments surrounded by eucalypts plantations, whereas in areas exposed to cattle ranching, populations of the same species consistently lack small individuals. At the regional scale, populations in fragments surrounded by pastures presented greater skewness (prevalence of small plants) than populations in reference areas, while populations surrounded by eucalypts plantations presented intermediate skewness. These results reinforce the notion that plantations have a higher conservation value for forest ecosystems than other commercial land uses, like cattle ranching. © 2010 Springer Science+Business Media B.V.
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This paper discusses the process of induced elevation in the watertable adjacent to the hydroelectric reservoir after its filling, once the dam is completed and the impoundment of the river begins. It is presented a discussion on the main impacts caused by the installation of such enterprise, focusing on induced elevation, considering how the process of change in groundwater evolves and presenting synthesis of previous studies developed on this.
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Includes bibliography
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Includes bibliography
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Includes bibliography
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Incluye Bibliografía
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Public policies encouraging the insertion of large industrial and commercial developments near highways, associated to exclusionary housing policies, have shaped over the past decades a new urbanization phenomenon; the sprawl. This is largely characterized by discontinuous and fragmented occupation, with random population densities. This phenomenon brings environmental and social impacts to the urban and rural population, in addition to a great burden for the Government. In line with this and considering the lack of discussion about the topic, this paper discusses some of those impacts observed in Londrina - PR, Brazil. The influence of urban sprawl in this city has shown to impact traffic, waterproofing rates and green areas, in addition to underutilizing the infrastructure due to large urban voids and vacant lots. With the data presented here, it is hoped that debates emerge on the importance of rethinking the plan, so that everyone can have legal access to the city (endowed with infrastructure), as well as the importance of developing strategies to contain urban sprawl. © 2011 Journal of Urban and Environmental Engineering (JUEE). All rights reserved.
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After nearly 80 years since the construction of its core, represented today by the city's central area, Londrina, located in the state of Parana, has the appearance of a new city but its features and trends of planning policies depict the bad examples of Brazilian cities. With a booming urban growth, from north to south of the county, the urban interstices represented by big voids in the middle of the city created speculation and the concept of an ideal city slowly disappeared. With a metropolitan appearance and, at the same time, with small town aspects, Londrina stands out as an automobile-oriented city, a fact that has impacted the livelihood of the population, generating environmental impacts for all social classes. This paper discusses how the form of occupation in Londrina, characterized by the sprawl phenomenon and its relation to car preference as a mode of transportation has generated urban environmental impacts. It was concluded that the choice of using cars in Londrina, as well in other medium-sized Brazilian cities studied by the comparative method, has increased and has generated bottlenecks in traffic. As a consequence, there is a constant expropriation of properties for widening roads and at the same time, the presence of various densities and urban voids that form an uneven urban space and an obstacle to efficient urban planning. © 2012 WIT Press.
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In this study, we used data from both experiments and mathematical simulations to analyze the consequences of the interacting effects of intraguild predation (IGP), cannibalism and parasitism occurring in isolation and simultaneously in trophic interactions involving two blowfly species under shared parasitism. We conducted experiments to determine the short-term response of two blowfly species to these interactions with respect to their persistence. A mathematical model was employed to extend the results obtained from these experiments to the long-term consequences of these interactions for the persistence of the blowfly species. Our experimental results revealed that IGP attenuated the strength of the effects of cannibalism and parasitism between blowfly host species, increasing the probability of persistence of both populations. The simulations obtained from the mathematical model indicated that IGP is a key interaction for the long-term dynamics of this system. The presence of different species interacting in a tri-trophic system relaxed the severity of the effects of a particular interaction between two species, changing species abundances and promoting persistence through time. This pattern was related to indirect interactions with a third species, the parasitoid species included in this study. © 2012 The Society of Population Ecology and Springer Japan.