886 resultados para bacia hidrográfica


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The vast hidric wealth of Brazil gets its watersheds more susceptible to impacts that compromise the water quality, affecting the ecosystem stability of aquatic environments. The decrease in the quality of water resources also results in a decrease of its multiple uses, especially in tourist areas of the coast, where the continuous flow of people to these sites increases even further the probability of inappropriate behavior of both tourists and local residents. Studies regarding the microbiological communities are still scarce, especially on the free-living protozoa that play unique roles in the food chain of aquatic ecosystems. Due to the large role played by this group of microorganisms in aquatic environments, the present study aimed at identifying the genus and species of free-living protozoa present in two sections of the Pium River, east coast of Rio Grande do Norte, making an association between the its occurrence and trophic conditions of the environment in which they are, also checking the bioindicator capacity of these organisms in water quality. It also aimed to conduct a survey with students to identify the main difficulties regarding the knowledge of free-living protozoa and hydric transmission diseases in two public schools near the river studied in the Pium district, county of Parnamirim. The survey was analyzed by means of questionnaires at both schools. Students identified several activities developed Pium river, highlighting its multifunctionality and importance to the region. A total of 76 taxa of free-living protozoa was recorded, of these, 33 were ciliates, 19 flagellates and 24 sarcodia. The spatial and temporal patterns of these organisms to both points studied revealed the bioindicator potentiality of some effective species identified. However, knowledge about the free-living protozoa proved quite lagged, presenting misconceptions that show them as pathogenic organisms exclusively, totally disregarding their ecological role. In order to remedy the flaws existing in students in relation to the functional role of protozoa, workshops were planned on these microorganisms while also addressing issues related to hydric transmission diseases through lectures, recreational activities and interactive presentations. These practical activities of Science Education had the goal of bringing students the context of local water resources, aiming to promote a greater clarification regarding of the functional role of free-living protozoa in aquatic environments

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Water scarcity is a reality for the inhabitants of the Brazilian semiarid region. The problem, in quantitative terms , is caused due to local climatic conditions due mostly to a water deficit. Qualitatively, results of multiple uses and resulting contamination by human activities. Eutrophication is presented as a threat to the sustainable use of water resources, in order to favor the predominance of dense populations of cyanobacteria, which can be potentially harmful to human health. The aim of this study is to understand the population dynamics of phytoplankton and cyanobacteria to assess water quality of reservoirs Santa Cruz do Apodi and Pau dos Ferros belonging to bacia Apodi Mossoró-RN . Water samples were collected monthly between October 2011 and May 2012 in reservoirs Santa Cruz do Apodi and Pau dos Ferros, in this latter , in Jan/12 we performed a diel profile . The abiotic variables obtained in the field and in the laboratory were: water temperature , dissolved oxygen , pH , turbidity , transparency , total nitrogen and total phosphorus . Phytoplankton samples were collected with a plankton net and bottle of Van dorn . Were performed : identification , quantification , calculation of biovolume , classification into functional groups and index calculation phytoplankton assembly ( Q ) , cyanotoxins were quantified by ELISA . Statistical analyzes supported the evaluation of the dynamics between biotic and abiotic factors. A questionnaire was conducted to examine the conceptions of the population, education professionals and students. The reservoir of Pau dos Ferros, shallow , turbid and eutrophic showed dominance of the functional group SN throughout the sample period . The phytoplankton biomass ranged from 20 to 70 mm ³ . L - 1, the lowest values coincided with the increase of the mixing zone and transparency, which contributed to the occurrence of a change in species composition phytoplankton . The application of the index Q proved relevant, the reservoir of Pau dos Ferros , depending on the species present , was classified ecologically as bad for almost the entire sample period . The reservoir Santa Cruz do Apodi showed low biomass ( 0.04 and 4.31 mm ³ . L - 1 ) and greater diversity in the phytoplankton composition . According to the index assembly (Q ), it showed moderate condition during most of the period influenced by different functional groups of typical meso- eutrophic environment (K S0, H1, C, F , J , E, D and N) . Associations of diatoms and green algae D and X1 succeeded populations of cyanobacteria in periods marked by greater instability in the system , caused by wind or rain. In summary , the occurrence of drought has a direct influence on the hydrological conditions of the reservoirs , in general, these events, reducing the reservoir level is directly related to decreased water quality and increased density of phytoplankton occurring predominance of cyanobacteria , the index Q reflected well to changes in phytoplankton composition , being a good indicator for biomonitoring of reservoirs in this study and survey of previous conceptions showed the need to work on environmental awareness for the preservation of water resources by conducting workshops for Environmental Education

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study includes the results of the analysis of areas susceptible to degradation by remote sensing in semi-arid region, which is a matter of concern and affects the whole population and the catalyst of this process occurs by the deforestation of the savanna and improper practices by the use of soil. The objective of this research is to use biophysical parameters of the MODIS / Terra and images TM/Landsat-5 to determine areas susceptible to degradation in semi-arid Paraiba. The study area is located in the central interior of Paraíba, in the sub-basin of the River Taperoá, with average annual rainfall below 400 mm and average annual temperature of 28 ° C. To draw up the map of vegetation were used TM/Landsat-5 images, specifically, the composition 5R4G3B colored, commonly used for mapping land use. This map was produced by unsupervised classification by maximum likelihood. The legend corresponds to the following targets: savanna vegetation sparse and dense, riparian vegetation and exposed soil. The biophysical parameters used in the MODIS were emissivity, albedo and vegetation index for NDVI (NDVI). The GIS computer programs used were Modis Reprojections Tools and System Information Processing Georeferenced (SPRING), which was set up and worked the bank of information from sensors MODIS and TM and ArcGIS software for making maps more customizable. Initially, we evaluated the behavior of the vegetation emissivity by adapting equation Bastiaanssen on NDVI for spatialize emissivity and observe changes during the year 2006. The albedo was used to view your percentage of increase in the periods December 2003 and 2004. The image sensor of Landsat TM were used for the month of December 2005, according to the availability of images and in periods of low emissivity. For these applications were made in language programs for GIS Algebraic Space (LEGAL), which is a routine programming SPRING, which allows you to perform various types of algebras of spatial data and maps. For the detection of areas susceptible to environmental degradation took into account the behavior of the emissivity of the savanna that showed seasonal coinciding with the rainy season, reaching a maximum emissivity in the months April to July and in the remaining months of a low emissivity . With the images of the albedo of December 2003 and 2004, it was verified the percentage increase, which allowed the generation of two distinct classes: areas with increased variation percentage of 1 to 11.6% and the percentage change in areas with less than 1 % albedo. It was then possible to generate the map of susceptibility to environmental degradation, with the intersection of the class of exposed soil with varying percentage of the albedo, resulting in classes susceptibility to environmental degradation

Relevância:

100.00% 100.00%

Publicador:

Resumo:

There are many applications coming from geomorphological studies and their different constitutive and inter related elements, to the implementation of public politics of planning and environmental management. This search presents an analysis of the environmental fragility of the watershed of Seridó River, situated between the states of Paraíba and Rio Grande do Norte (Brazil), including the identification of possible unstable areas. It is based on the methodological approach of Ecodynamics of the French researcher J. Tricart (1977) and on the operalisation proposal advocated by the Brazilian J. Ross (1994), related to the Potential and Emerging Ecodynamic Units, grounded in the Relief s Dissection Index or the topographic roughness, soil, rainfall and land use/vegetal cover. Under a quantitative perspective, the results obtained from the analysis of the watershed can be divided into classes of potential fragility: around 2.613,0 km² of low intensity, 5.188,4 km² of medium intensity and 2.585,5 km² of high intensity. Concerning the emerging fragility, the results are close to 2.212,0 km² of low intensity, 6.191,23 km² of medium intensity and 2.062,34 km² of high intensity. In the case of the watershed in question, the environmental degradation is particularly effective in the areas more dissected, where the ecological conditions, in synergy the environmental degradation, prevent the regeneration of vegetation when arises an opportunity for the (re)establishment of its equilibrium tenuous. The collected data is relevant for the territorial and environmental planning of the watershed, once we can still verify a close association of the cities on the central area of desertification with the areas of high environmental instability/fragility. This is an important tool to the understanding of the potential susceptibility of the natural and anthropic environments related to the advance and/or intensification of the erosion process, rock falls, mass movements, among other phenomena inside the potential unstable areas. From this perspective, the continuity of this research becomes extremely important to the understanding and arrangement of the process, together with the engendering and sustainability of the system in its totality; in narrow correlation because their potentialities, constraints and alternatives on Seridó River watershed, and in all the semi-arid region with similar characteristics

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hydrographic basins always exercised a big fascination over humankind that attracted for its scenery beauty or for its richness in natural resources, had been acting in order to modify these important ecosystems without, therefore, considering the possible consequences of these changes. The attributed importance to the coast ecosystems, in eminence to the hydrographic basin of Punaú river and adjacent areas, is had when it s verified the diversity of the ecosystems that contemplate it. Hydrographic basin in evidence in Rio Grande do Norte state, occupies an area of nearly 652.71 km², being it sited in the homogeneous micro-region Litoral Nordeste, with a regional population estimated in nearly 75,188 inhabitants, according to the Anuário Estatístico do Rio Grande do Norte 2004. The region of the researched basin is formed by seven municipal districts related as it follows: Maxaranguape, Pedra Grande, Pureza, Rio do Fogo, São Miguel de Touros, Taipu and Touros, but Maxaranguape, Rio do Fogo, Touros and Pureza have a direct participation in the basin. Basin in study have it lands evaluated according to the agriculturist aptitude by the conventionally methodology practiced in the country, having as objective, then, a compara-tive analysis between the ambient unities, Aeolian littoral and coast tray, identified in the researched area. From the characterization of the physic way of the area in study and owning the kept data, it was proceeded the integrated analysis of the structural elements of the landscape which were evidenced that the fragile areas are associated with the areas of agriculture cultivation, such as the ones of irregular occupation. About the degradation, the ambient diagnostic of the basin indicated that the equivalent to the Aeolian Littoral Ambient Unit correspond to the bigger pledging of the ambient quality, in other words, high ambient fragility, being this result due to the use and occupation of the soil, propitiating this way, vulnerability in the vegetal cover of the area, despite it disposes of a low agriculture cultivation percentage. Already in the Coast Ambient Tray, is emphasized the medium ambient fragility, despite of the high index of cultivated area. In a general way, the total area of the hydrographic basin of Punaú river and adjacent areas presented ambient impacts over the tolerance limit, indicating the necessity of a review of the practices of use and handling of the soil, reforesting of the water courses edges, control of erosion and contamination of the aqueous in the perspective to reduce the effects of the impacts due to the use and occupation of the basin in regard. The present search evaluated the ambient impacts diagnosised in the hydrographic basin of Punaú river and adjacent areas, pointing the causes and the probable consequences of the damages caused by these impacts to the basin ambient. From the analysis of these data, if was possible to become explicit how they are fundamental as key elements in the process of decision taking in the ambient questions

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A incidência das leishmanioses tegumentar e visceral americanas, em especial esta última (LVA), em hospedeiros caninos e humanos, encontra-se em crescente processo de expansão no Estado de São Paulo. Para a vigilância epidemiológica dessas endemias, torna-se fundamental o conhecimento da distribuição e da ecologia das diferentes espécies da fauna flebotomínea vetoras. Assim, a divulgação de novos encontros de seus vetores, sobretudo da Lutzomyia longipalpis, o principal vetor da LVA, é fundamental para apontar novas áreas de risco para a transmissão dessas doenças. Neste estudo, capturas de flebotomíneos foram realizadas em ambiente domiciliar, peridomiciliar e de mata, em diferentes localidades rurais dos municípios de Ipeúna e Itirapina, entre outubro de 2001 e fevereiro de 2004. Foram utilizadas armadilhas luminosas automáticas do tipo CDC, das 18h às 8h, em 14 noites, resultando 420 horas de exposição. Foram capturados 177 flebotomíneos pertencentes a doze espécies. A espécie mais abundante, Nyssomyia neivai, apontada como a principal vetora de LTA no Estado, contribuiu com 85,4% dos espécimes capturados em Ipeúna. O encontro de Lutzomyia longipalpis em uma caverna em Itirapina, aponta para o risco de estabelecimento da LVA na área e a necessidade de mais estudos locais sobre sua ecologia, sobretudo em relação à ocupação de ambientes antrópicos.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work had as objective to quantify the reforestation for water retention in the Palmital Stream watershed, County of Jaboticabal, SP, by using the methodology of compensatory forestation for retention of water in watersheds. This methodology esteems the retention of water in watersheds considering the world medium value of destiny of the water in the hydrologic cycle, the use/occupation of the soil (forest, pasture and agriculture) and its permeability. The watershed in this study presents an area of 10,625.21 ha, being 237.75 ha at forest, 467.01 ha in pasture and 9,237.57 ha in agriculture. The medium values of the permeability identified in the soils were of 94.81 mm h -1 in forest, 8.99 mm t -1 in pasture and 36.01 mm h -1 in agriculture (sugar cane). Considering that should infiltrate in the soil 20.55% of the water that precipitates on the watershed, and, that the losses of water in forest areas is considered standard, the total estimated volume to compensate the excessive loss that occur in the areas of pasture and agriculture is 12.21 million of m 3ano. The compensatory forestation to retain that volume of loss should contemplate an area of 942.73 ha (8.87% of the area of the watershed). The reforestation can be priority in permanent conservation area or in areas of Legal Reserve.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In areas where human activities, as agriculture, are developed land use contributes to physical, chemical and biological characteristics of water. This study aimed to identify physical and chemical variations of the water monitoring network in 4 first magnitude watersheds with different land use/occupation in the hydrographic basin of the Glori Farm Creek in the city of Taquaritinga, State of Sao Paulo, from February to July, 2005. The methodology consisted of weekly sample water collections to naalyze turbidity, temperature, dissolved oxygen, pH and electric conductivity. The characterization of the hydrological conditions of the watersheds showed that agricultural activities, including the productive system of the sugarcane cultivation, have affected the quality of water resources.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present work had the objective to elaborate the map of land use and vegetation covering from Tijuco river watershed, Ituiutaba-MG, based on digital images obtained by satellite from CBERS 2, through automatic delimitation of permanent preservation areas followed by identification of land use conflict based on the Brazilian Forest Code (Law no 4771/1965) and National Council of Environment's Resolution no 303/02. This paper analyzes, through quantitative parameters and the use of Geographic Information System, the maintenance tracks of width recommended by the legislation for permanent preservation areas over water bodies. The results showed a deficit of conserved areas along the riverbanks of 2334 ha that are not in compliance with the legislation. The pasture occupies unduly 0.97% of the area of the basin in the permanent preservation areas at the riverbanks, while agriculture occupies 0.38%.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

By remote sensing, geodatabase digital processing, information and expeditions to Capivara's sub-basin, was possible to identify the changes in the landscape mainly the expansion of eucalyptus, sugar-cane, and orange trees, being the last two, mainly on the Periferic Depression of Basaltic Cuesta. A significant portion of the soil on this geological area is formed from sandstones, providing high permeability to them, making them important places to groundwater recharge areas as sensible to contamination by pesticides. Throughout last decade was observed that the native vegetation fragments stabilization, keeping a reason of 26.5% on the land used between 2000 and 2010. The pasture decrease being substituted by eucalyptus, sugar-cane and orange trees call attention for the changes in the agribusiness model demanded by the current economic and social necessity. Pasture decrease followed by erosions decrease on sub-basin is evidence that these two aspects are strongly related.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper presents the results of the longitudinal profile analysis and the application of gradient index (RDE) in the Patos River, a tributary of the Ivaí River basin, PR. The goal is identify and quantify the anomalous zones along river course concerning their genesis - activity neotectonic or/and lithological imposition. The Patos River has a length of 127 km and a relief amplitude of 660 m, The occurrence of an important knickpoint in the middle course the Patos River can be divided into two stretches. Of the 22 sections measured, 10 were considered anomalous, distributed in both upper and lower course. In the upper course, over a basaltic bedrock of the Serra Geral Formation the RDE values are lower than those in the lower course, where river flows over sedimentary rocks of the Terezina Formation. The 2 nd order anomalies are related to lithological changes, relief alignments and channel confluences - as in the case of São João River. The 1st order anomalies are linked to differences in rock resistance associated with structural control, which provides the formation of waterfalls.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The sediment production in river basins is an important aspect for planning the land use. Mathematical models are useful tools for analyzing the problem by providing speed, convenience and flexibility to the simulations of current conditions and future. In this article we evaluate a methodology to simulate the sediment production combining the MUSLE, a hydrologic model (ABC) and a GIS in different scenarios of land use. The models used showed good performance for purposes of planning land use, as well as for agricultural and environmental planning.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.