992 resultados para Recuperação de terra
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GPS active networks are more and more used in geodetic surveying and scientific experiments, as water vapor monitoring in the atmosphere and lithosphere plate movement. Among the methods of GPS positioning, Precise Point Positioning (PPP) has provided very good results. A characteristic of PPP is related to the modeling and / or estimation of the errors involved in this method. The accuracy obtained for the coordinates can reach few millimeters. Seasonal effects can affect such accuracy if they are not consistent treated during the data processing. Coordinates time series analyses have been realized using Fourier or Harmonics spectral analyses, wavelets, least squares estimation among others. An approach is presented in this paper aiming to investigate the seasonal effects included in the stations coordinates time series. Experiments were carried out using data from stations Manaus (NAUS) and Fortaleza (BRFT) which belong to the Brazilian Continuous GPS Network (RBMC). The coordinates of these stations were estimated daily using PPP and were analyzed through wavelets for identification of the periods of the seasonal effects (annual and semi-annual) in each time series. These effects were removed by means of a filtering process applied in the series via the least squares adjustment (LSQ) of a periodic function. The results showed that the combination of these two mathematical tools, wavelets and LSQ, is an interesting and efficient technique for removal of seasonal effects in time series.
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This research aimed to study land use capability classes in Pratânia, São Paulo State, Brazil, by using the Geographic Information System (GIS), in order to find out the appropriate planning system for soil use. The watershed covers an area of 21,773.61 ha and is located among the coordinates 22°44'48S and 22°52'17S and 48°38'21W and 48°48'07W. The land use capability map was made from the slope and soil maps, based on the features of each kind of soil and the land use capability table for class assessment. It was possible to conclude that IIIs was the most significant subclass. Slope classes from 0% to 20% were present in more than 97% of Pratânia, being the plane areas the most representative ones (55%). GIS showed to be an excellent tool for determining land use capability, because the geoprocessing use facilitates and activates the digital data crossing, allowing its storage for future environmental planning.
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Land use dynamics is a consequence of socioeconomic system cycles. In this context, this work was developed aiming to evaluate land use alterations in Santa Bárbara watershed (Pelotas - Brazil), during 53 years (1953 - 2006), evidencing socioeconomic elements that contributed to this process. For land use dynamic analysis, maps of 1953, 1965, 1995 e 2006 were elaborated. Spatial changes that happened in Santa Bárbara watershed represent a regional process: pasture areas had decrease while culture lands had a gradual increase. This conjuncture is a consequence of the crisis in livestock destined to salted and dried meat production and of the food industry growth in Pelotas that impelled urban expansion, forest area reduction and artificial water reservoirs increase. © Scripta Nova, 2010.
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A comparative evaluation was made of the use of natural language versus two specialized indexing languages, aiming to demonstrate the influence of the availability of indexing languages on the functioning of information retrieval systems. The study was conducted within the ambit of the construction of search strategies by subject in online university library catalogs. The precision ratio was calculated to determine the accuracy of each indexing language in subjectbased information retrieval. From the comparative evaluation of the use of indexing languages, it was concluded that the term specificity required by the user during retrieval was more satisfactory when the query was made through controlled languages, whose availability and simplicity is also an indispensable requisite.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This study aimed at analyzing the geomorphologic dynamics and its relationship to human interference and ownership of relief, towards a systemic approach, through the interpretation, in an integrated manner, of cartographic documents made from techniques of geomorphologic cartography and of land use. By stereoscopic pairs of aerial photographs, it was prepared the Geomorphological Map and the Land Use Map, respectively based on Tricart's (1965) and Ceron and Diniz's (1966) technical procedures. The unit of the research analysis refers to the basin of Tijuco Preto Streamlet (SP) which is located at the Geomorphological Province of São Paulo state Peripheral Depression between latitudes 22°42'17 and 22°51'36 S, and longitudes 47°30'30 and 47°37'03. In general, it was possible to notice that this basin has been experiencing linear erosion processes, where it was mapped many erosion furrows, grooving and creeping, besides several slope breaks. These processes are associated with a conjunction of circumstances, and the anthropic one is mostly represented by sugarcane monoculture and by urbanization, which are crucial agents in activating erosion processes and in direct interfering on the dynamics of river and rain flow at the basin of Tijuco Preto Streamlet.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Environmental factors are important in agriculture and need to be considered for getting good degree of development and reasonable efficiency, by reducing their operating costs. To this end, land use shall be appropriated to the conditions offered by the physical elements of the landscape. By facing such questions, this paper aims is to present of mapping the ability of land use of the hydrographic basins Cavalheiro Stream basin (in the city of Analândia - São Paulo State - Brazil) which presents serious erosion problems. Besides it aims to assess if the current land use in this area is consistent with the identified land use ability. For this we have made a cartographic document that spatializes the various classes of usability and its main restrictions. The correlative analysis between that document and land use data showed that Cavalheiro Stream's current use is predominantly inappropriate with the usability of land, which was identified from the physical attributes of the studied area, except for a few sites that are used for forestry and pasture placed in Western, Eastern and Central-South.
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Agricultural and mining activities are directly related to changes in natural landscapes. From the perspective of anthropogenic geomorphology supported by general systems theory, this research has developed, in order to identify and analyze changes in the land use, mainly from agriculture and the exploitation of clay, and its implications in the hydro-geomorphological characteristics in the Santa Gertrudes Stream watershed (SP). This area is within the context of the Ceramic Pole Santa Gertrudes (SP), which besides its importance as a supplier of raw material, is characterized as the largest center of international reference in ceramic tiles on the American continent. For this purpose, we made land use and geomorphology maps of two scenarios, corresponding to the years 1962 and 2006, which allowed the identification of changes caused by human activities on the landforms of the area, such as the increase in area of parcels intended for mining activity, which went from 3.1% to occupy 19% of the catchment area of the respective period and that, among other changes, gave rise to new forms of relief as, for example, in levels of pit mining abrupt and smooth. The results indicate that the main features of representative of human changes in relief are represented for opening of large clay mining pits and agricultural activities, which intensified the denudation and sedimentation processes in the Santa Gertrudes Stream watershed.
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Soil attributes reflect influence of the geomorphic surfaces. Therefore, the objective of this work was to investigate the influence of the geomorphic surfaces on soil attributes in a topossequence from low lands to high lands in the Humaitá region, AM. A transect of 4.5 km, from the top of the slope towards the low lands was established and the geomorphic surfaces were identified and limited according to topographic and estratigraphic criteria, based on detailed field investigation. Twenty soil samples were collected in each one of the slope segments within the geomorphic surfaces (G.S.), at the following depths: G.S. I: LAa (0.0-0.16 and 0.48-0.79 m); G.S. II: Lad1 (0.0-0.13 and 0.44-0.70) and Lad2 (0.0-0.10 and 0.30-0.55 m); G.S. III: RYve1 (0.0-0.18 and 0.51-0.89) and RYve2 (0.0-0.23 and 0.58-0.91 m). The sampling depths were determined by the surface and subsurface horizon depths, defined during the soil morphological description. Physical analysis involved particle size distribution, disperse clay, soil and particle density and total porosity. The chemical analysis involved determinations of pH in water and KCl, exchangeable cations, exchangeable Al, total acidity (H+Al), available P, organic carbon. The relief variations contributed to the presence of dystrophic soils in the geomorphic surface I and eutrophic soils in the geomorphic surface III. The multivariate statistical techniques were able to separate three heterogeneous groups, equivalent to the mapped geomorphic surfaces.
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It is well established in the literature that musculoskeletal injuries are important compromising agents in the performance of Thoroughbred horses. In Brazil, there are no studies on the interrelation between lay-up period post-injury and retirement of racehorses due to musculoskeletal injures. The aim of this study is to determine the relationship between rehabilitation times of track injures and variables of prior race performance and later return to competitions. The radiographic reports and athletic history of 416 thoroughbreds during the period between 2003 and 2006 were examined; they were selected based on continued presentations after injury diagnosis. The temporal variables (post-injury rehabilitation time) and performance variables (race score before and after injury) were evaluated by multivariate correspondence analysis of the data and represented in perceptual maps. Correspondence was observed between most of the animals that had a short lay-up post-injury and variables that denote decline in subsequent performance. Considering the integrity of the bone healing process as crucial for the horse to be able to handle later training routines and competitions, shortening this period could lead to an imbalance of the bone repair metabolism, thus resulting in performance decline and compromise of the horse athletic career.
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Incluye Bibliografía
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Pós-graduação em Aquicultura - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)