940 resultados para Alto Guadalentín Basin


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A twenty-year period of severe land subsidence evolution in the Alto Guadalentín Basin (southeast Spain) is monitored using multi-sensor SAR images, processed by advanced differential interferometric synthetic aperture radar (DInSAR) techniques. The SAR images used in this study consist of four datasets acquired by ERS-1/2, ENVISAT, ALOS and COSMO-SkyMed satellites between 1992 and 2012. The integration of ground surface displacement maps retrieved for different time periods allows us to quantify up to 2.50 m of cumulated displacements that occurred between 1992 and 2012 in the Alto Guadalentín Basin. DInSAR results were locally compared with global positioning system (GPS) data available for two continuous stations located in the study area, demonstrating the high consistency of local vertical motion measurements between the two different surveying techniques. An average absolute error of 4.6 ± 4 mm for the ALOS data and of 4.8 ± 3.5 mm for the COSMO-SkyMed data confirmed the reliability of the analysis. The spatial analysis of DInSAR ground surface displacement reveals a direct correlation with the thickness of the compressible alluvial deposits. Detected ground subsidence in the past 20 years is most likely a consequence of a 100–200 m groundwater level drop that has persisted since the 1970s due to the overexploitation of the Alto Guadalentín aquifer system. The negative gradient of the pore pressure is responsible for the extremely slow consolidation of a very thick (> 100 m) layer of fine-grained silt and clay layers with low vertical hydraulic permeability (approximately 50 mm/h) wherein the maximum settlement has still not been reached.

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Multi-sensor advanced DInSAR analyses have been performed and compared with two GPS station measurements, in order to evaluate the land subsidence evolution in a 20-year period, in the Alto Guadalentín Basin where the highest rate of man-induced subsidence (> 10 cm yr−1) of Europe had been detected. The control mechanisms have been examined comparing the advanced DInSAR data with conditioning and triggering factors (i.e. isobaths of Plio-Quaternary deposits, soft soil thickness and piezometric level).

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Considering the great importance of the Itupararanga Reservoir, Upper Alto Sorocaba basin/SP, this study aimed to report the variations of some parameters of water quality in the spatial and temporal gradients in this multipurpose res- ervoir. The eutrophication of this reservoir was checked using the Carlson Index Modified and the results indicate that the surface water were classified as eutrophic and mesotrophic in wet and dry periods, being characterized the better quality of water in wet period. In the vertical gradient the results showed a stratiphication in all parameters analyzed, except for the electrical conductivity, with good correlation between total phosphorous and chlorophyll-a, indicating that eutrophication of the reservoir changes the conditions of algal growth, mainly in its initial area. Immediate inter- ventions are needed, which must be directed to planning of land use, domestic effluents treatment, taking to an inte- grated management of this important watershed located in the São Paulo State.

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El objetivo general de este trabajo fin de máster es el análisis y síntesis de los principales estudios realizados, hasta la fecha, así como la profundización en la investigación sobre la importante tasa de subsidencia que está experimentando la cuenca del Alto Guadalentín durante las últimas décadas. El objetivo general anteriormente expuesto se puede dividir en los siguientes objetivos específicos: • Confirmación de que la subsidencia del Valle del Guadalentín está provocada, principalmente, por la sobreexplotación de acuíferos, y en todo caso, detectar si existe alguna causa secundaria, como la tectónica. • Justificación de los motivos por los cuáles existen dificultades para encontrar los signos externos de subsidencia, del apartado anterior, en el Valle del Guadalentín a diferencia de otros casos del mismo tipo de subsidencia en el mundo. • Localización e identificación de casos concretos de consecuencias físicas del fenómeno de la subsidencia en el terreno, tales como grietas y hundimientos en el terreno, patologías en construcciones y variaciones anómalas de la pendiente en parcelas y canales de riego.

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Two sampling points were chosen and forty samples were collected between January and December 2006 at Alto Sorocaba basin. The rainwater pH varied from 5.46 to 6.36 (Ibiúna) and 5.26 to 6.81 (Itupararanga), being Ca2+ the main ion responsible for controlling the rainwater pH. The ionic concentrations decreased in the following order: Ca2 +>Na+> Mg2+>K+ for cations and SO4(2-)>HCO3->NO 3->Cl- >PO4(3-) for anions. The annual atmospheric deposition appeared to be controlled mostly by following sources: mining activities and cement factories (Ca2+ and HCO3-), natural soil dust (Na+, Mg2+ and HCO3-), fossil fuel burning (SO4(2-)) and agriculture activities (K+, NO3- and PO4(3-)).

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Geologia Regional - IGCE

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Pós-graduação em Ciências Biológicas (Zoologia) - IBB

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Relación de experiencias narradas por los alumnos y algunos profesores del centro de adultos Alto Guadalentín de Lorca (Murcia) que refleja la pluralidad de perfiles que alberga este tipo de centros de enseñanza: personas mayores, paradas, inmigrantes de otros paises, jóvenes con carencias formativas, amas de casa. Esta diversidad está unida por el objetivo común de aprender y elevar su nivel cultural ya sea para encontrar un trabajo, retomar estudios abandonados, acceder a estudios superiores o por el simple placer de aprender. Estos centros son el reflejo de la sociedad en la que confluyen personas con experiencias vitales muy distintas, de distintas procedencias, edades, razas y culturas que enriquecen a todos los componentes de la comunidad educativa..

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The geographic area of the present study corresponds to the basin of the Itiquira river high course (Figure 1), in the portion that extends from the tributaries of its source, in the east of the plateau Correntes/Itiquira, in the neighbourhoods the city of Alto Garç as, to the scarp of the São Jerônimo mountain range, toward the west of Itiquira, in the state of Mato Grosso, totalizing 5,361 km 2. The area is placed in the eastern part of the Alto Paraguai basin, in the western portion of the Paraná Sedimentary Basin plateau. Through GIS techniques, it was possible to asses total soil losses from the Itiquira river basin, considering the years of 1966, 1985 and 1996, being based on the Universal Soil Loss Equation. Thus, in 1966 the basin lost 201,546.94 ton of soil, with an average loss of 0.37 ton/ha/year. Considering that the total area of the Itiquira river basin is of 536,100 ha, while in 1985 the soil losses had passed to 1,760,833.40 ton, with an increase of approximately 8.5 times. The average of soil losses in 1985 was of 3.28 ton/ha/year. In 1996 the basin lost 1,662,043.24 ton, with a reduction of only 9.4% in relation to 1985 but, in relation the 1966, the increase continued in the order of 8 times. The average losses per hectare in this year was in the order of 3.10 ton/ha/year (Chart 1). The map of potential of the laminar erosion for 1966 (Figure 3), shows to the highest values in small areas, situated in the northeast of the area, in Alto Garças, with values between 10 the 20 ton/ha/year and some spots in sources of the Itiquira and Ariranha rivers, with values between 1 the 5 ton/ha/year. In a general way, however, the area presents low soil loss for laminar erosion in this year, with inferior values to 1 ton/ha/year. The higher class of erosion, over 10 ton/ha/year, occupied 2,947 ha in 1966. In the year of 1985 (Figure 4), the erosive process spread over the entire studied area, and the class of erosion over of 10 ton/ha/year, already started to occupy 78,437 ha, implying an increase of approximately 27 times in 19 years. A strong increment in the erosive process was noticed in the western part of the area, to along the BR-163 road, exactly where great areas of natural vegetation (open pasture) had been transformed in culture and pasture areas. In the north-eastern part of the area it was also noticed an increment in the erosive process in agreement with the increase of culture areas and reduction of the natural areas, but it was not of so intense form as in the western portion of the area. In the year of 1996 (Figure 5), the class of erosion over of 10 ton/ha/year had diminished for a total of 53.499 ha noticing a retraction of the erosive process in the western part of the area, alongside the BR-163 road. On the other hand, it occurred a strong increment in the northern part of the area, in the neighbourhoods of the city of Alto Garças, alongside the BR-364 road and part of the MT-040 road. In a general way, in the outskirts of the city of Itiquira, in the central part of the area, it was verified an increase of the amount of zones with erosion between 0-1 ton/ha/year, passing to the immediately superior class, of 1-3 ton/ha/year; scarce data of hydrosedimentology in the UHE Itiquira (1999), shows good agreement with the values gotten for the EUPS (Chart 2). Based on the hydric classification proposal for FAO (1967) (Chart 3), it is noticed that areas with high degree of erosion (> 50) in the analysed area are very restricted, occupying 493 ha in 1985 and 332 ha in 1996 (Chart 4). In 1996 appeared as isolated spots in the north of Itiquira and Alto Garças, however beyond limits of the Itiquira river basin. These areas require special cares in its use as agricultural areas. Aiming at identifying and indicating the areas of potential risk of erosion and that need implementation of conservation practices, it was elaborated the map of limit of tolerance to the soil losses. In 1966 (Figure 6), areas with soil losses over of the tolerable were restricted to small spots located in the eastern part of the area, occupying 0.43% of the total of the area; already in 1985 (Figure 7), this percentage passed to 5.86%, spreading for all the area; in 1996 (Figure 8) it is observed a fast reduction of the areas with soil losses over of the tolerance limit, passing 5.43% of the total of the area. All the areas with losses over of the tolerable value must be considered as risk areas and were done in these areas studies for implementation of conservation practices.

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Pós-graduação em Ciências Biológicas (Zoologia) - IBB

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The present study sought to develop a methodology to analyze the water quality based on concepts and methods of climate and climatology respectively. In this way, it was tried to relate techniques and methodologies hydro and limno-meteorological with a rhythmic analysis technique developed within the Brazilian geographical climatology to assess and analyze the blooms of cyanobacteria, the main index of water quality found in reservoirs of “Alto Tietê” Basin and consequently the Metropolitan Region of São Paulo, an area of high environmental complexity due to its high degree of development and high population density. The meteorological data used to develop the study were collected from the meteorological station of the IAG / USP and the limnological data were collected from the Hydrological Monitoring System implemented by SABESP in Billings and Guarapiranga reservoirs as well as data laboratory of the same entity. The results obtained by the rhythmic and integrated analyze showed that the process of blooms of cyanobacteria is dependent not only on one specific factor, but a combination of meteorological factors that may disrupt the stability of reservoir and which can, during the stabilization process, provides the necessary conditions to the development of cyanobacteria. It was also shown by the results that the pace of Atlantic Polar Front Entrance during the winter in São Paulo, is a limiting factor to the growth of cyanobacteria due to their high frequency, keeping the reservoir balance throughout the period. Furthermore, another importance of this study is the possibility of prevention and forecasting periods which are inappropriate for the use of these reservoirs mainly for recreational activities