928 resultados para Onyar (Catalunya : Conca hidrogràfica)
Resumo:
O conteúdo da presente dissertação aborda a importância da caracterização dos solos, na medida em que estabilidade dos taludes é um fator que depende fortemente da constituição e do tipo de solo presente nos maciços. A realização deste estudo incide sobre os solos da bacia hidrográfica da ribeira de Santa Luzia. O motivo da escolha da bacia em causa prende-se com o facto de a mesma ser uma das ribeiras que, atualmente se encontra sob observação através do projeto “MonitorizaRibeiras” do LREC. Os ensaios laboratoriais de caracterização físico-mecânica dos solos constituem uma das componentes de maior relevância na engenharia geotécnica. Neste trabalho a caracterização mecânica é feita através de ensaios de corte direto (em caixa de corte), que permitem obter os parâmetros de resistência do solo (ângulo de atrito e coesão). A caraterização física foi efetuada recorrendo a ensaios simples que permitem determinar os índices físicos do solo, mais particularmente: determinação da baridade seca in situ, análises granulométricas, determinação de limites de consistência de Atterberg e do teor em água natural, densidade de partículas sólidas e determinação da quantidade de matéria orgânica. Os parâmetros obtidos permitem depois a realização de uma análise a vários taludes com diferentes inclinações, de modo a verificar que influências tais parâmetros geram na obtenção do Fator de Segurança. Verifica-se que à medida que o teor em água aumenta, essa influência traduz-se na perda de resistência de um solo. Tal análise permitiu determinar quais as zonas da bacia de Santa Luzia que com as características obtidas e nas condições estudadas se encontram em maior perigo de escorregamento. Os sensores de saturação do solo, sendo uma útil ferramenta de monitorização remota foram alvo de pesquisa nesta dissertação. Esta pesquisa foi realizada com propósito de contribuir com informação, que posteriormente auxilie, na implementação destes equipamentos no sistema do projeto “MonitorizaRibeiras”.
Resumo:
Com a análise das características morfométricas procura-se entender a relação solo-superfície, em decorrência dos processos erosivos sobre estruturas e litologias variadas. Neste trabalho, objetivou-se avaliar as características morfométricas do padrão de drenagem e do relevo em microbacias hidrográficas de 2ª ordem de magnitude, em Latossolo Vermelho-Escuro e Argissolo Vermelho-Amarelo, com vistas ao planejamento agroambiental da Bacia Hidrográfica do Córrego Rico, município de Jaboticabal, SP. O estudo foi baseado em fotografias aéreas, pancromáticas, verticais na escala 1:35.000 da região administrativa de Ribeirão Preto. Com técnicas de fotointerpretação, foram traçadas a rede de drenagem e respectivas microbacias hidrográficas, onde as variáveis selecionadas foram determinadas. As classes de risco de degradação, resultando no uso potencial do solo, foram determinadas de acordo com o coeficiente de rugosidade. As características do padrão de drenagem e do relevo repercutiram no comportamento hidrológico e litológico das microbacias hidrográficas, possibilitando a diferenciação entre as unidades de solos. A densidade de drenagem e a amplitude altimétrica foram as características que mais contribuíram para o poder discriminatório na relação solo-superfície. Na análise conjunta do potencial de uso do solo, verificou-se, principalmente, adequação para agricultura nos Latossolos e pecuária e, ou, reflorestamento nos Argissolos.
Resumo:
O presente estudo trata da avaliação da degradação ambiental da bacia do Rio Uberaba, situada no triângulo mineiro, com área de 241.904,30 ha, abrangendo os municípios de Uberaba, Veríssimo, Conceição das Alagoas e pequena porção de Planura. Neste estudo, foi produzido o mapa de degradação ambiental contendo quatro níveis: baixo, moderado, acentuado e severo. Os parâmetros utilizados nesta avaliação foram: vegetação, topografia, solo/geologia, potencial natural de erosão, mecanização, área agrícola, densidade populacional, pecuarização e área de conflito, aos quais foram atribuídos pesos. Para o nível de degradação “baixo”, foram definidos valores ≤ 13 pontos. Para o nível “moderado”, valores situados no intervalo de 14 a 16. Entre 17 e 19 pontos para o nível “acentuado”, e o nível “severo” com valores ≥ 20 pontos. Este estudo consolida as consequências do uso inadequado das terras, não respeitando a sua aptidão natural. As áreas com nível moderado de degradação representam 47%, áreas de nível acentuado (48%), e severo (4%) representam 52%, o que revela indício muito forte no avanço da destruição dos recursos naturais. As áreas classificadas com nível baixo representam apenas 1%, bastante inexpressiva, destacando o descaso na preservação dos recursos naturais.
Resumo:
Com o objetivo de verificar a influência de remanescentes de vegetação ciliar e da ação antrópica na qualidade da água, estudaram-se quatro nascentes, sendo duas com a presença de vegetação natural remanescente e duas com predominância de atividades agrícolas. Essas nascentes fazem parte da bacia hidrográfica do Córrego Rico, estando localizadas nos municípios de Taquaritinga e de Guariba - SP, em duas classes de solo: Argissolo e Latossolo, respectivamente. Definiram-se pontos de coleta da água nas nascentes e ao longo dos cursos d'água (entre 0 a 50 m da nascente), em dois períodos (chuvoso e seco). Foram analisadas as seguintes variáveis: cor, pH, temperatura, turbidez, alcalinidade, dureza total, dureza em magnésio, dureza em cálcio, fósforo, nitrogênio e demanda bioquímica de oxigênio. de maneira geral, ocorreu agrupamento por nascentes e também por períodos, confirmando que os períodos de amostragem, assim como as características e diferentes usos do solo influenciam na qualidade da água das microbacias. As variáveis cor, turbidez, alcalinidade e nitrogênio total foram as que apresentaram maior importância relativa nas variáveis canônicas.
Resumo:
Due to the increasing activities and its disordered occupation, the catchment of the Pitimbu river is reason of concern for the population, since the river empties in the lagoon of the Jiqui where 30% of the water of this lagoon are caught for the supplying the city of Natal, playing an important fuction in the supply of water superficial for the capital of the Rio Grande do Norte. The superior stretch of the hydrography catchment of the Pitimbu river - Macaíba/RN, object of this study, is denoted by the eminently agricultural occupation with the use of the irrigated agriculture in the many properties that compose this stretch. Because of this becomes necessary to analyze the availability of the water resources in the catchment of the Pitimbu river, in the superior stretch, collating with the use and occupation of the existing terrain. The stretch in study was divided in eight points which had been performed tests throughout the water and analyzed the parameters physicist-chemistries and heavy metals that are praised by resolution CONAMA nº 357 e, visits in field with photographic survey for characterization of this verifying the situation where if it finds the river. The stretch presented some divergence in the parameters of pH and iron, however the results denote a characteristic of the region. The great amount of slide barrages throughout the river and the wet street was observed, had also verified near the edges the launching of garbage and, the great amount of aquatic vegetation. With this it is concluded that the water of the river can be used for human supplying, therefore inside presents a quality of drinking waters of the standards demanded for resolution CONAMA nº 357, in this way, the stretch in study could be adopted as an Envoiremental Area Protection (APA), to preserve and to guarantee, at least in this stretch, that its condition remains unchanged and continues to supply of permanent form a water of excellent quality
Resumo:
The present research has the purpose of planning the management of the water resources of the Seridó River watershed, in the state of Rio Grande do Norte, Brazil. It has an emphasis on the amount of surface water available in this region, to provide a sustainable water supply. Based on data and information collected from public departments responsible for the management of the water resources of the Rio Grande do Norte state, well as on researches related to water resources , a watershed balance was done, and the results suggested the transposition of the waters from the Piranhas-Açu river watershed taken from the Oiticica and Armando Ribeiro Gonçalves reservoirs, integrated with the construction of 2 hidroelectrical plants and 2 elevation stations, to pump the amount of water needed to the expected demand in some public dams of the region until 2020. So, with the use of the surface water potential that exists in the region, it was demonstrated that, on the contrary of the public policies implemented in the past and in the current by the federal and state realm, it is possible to supply the currently water demands and also the future ones, in a sustainable way, without the need of importing outter water to the respective watershed. Finally, it was proposed the implementation of the Water Resources Plan in the Seridó region WRPS, aiming at providing an auto-sustainable development by significantly diminishing the effects of the dry seasons in that region, by considering the economic, social and environmental sustainability
Resumo:
The Pirangi beach is located in the eastern coastline of Rio Grande do Norte state, in the municipality of Parnamirim and Nísia Floresta. In it flow into Pirangi Watershed (PW), whose water receives large amounts of pollutants, mainly domestic and industrial sewage from districts where pass the rivers that consist it, compromising, thus, the bathing water quality of the Pirangi beach. Bearing in mind the importance of water sanitary quality to ensure an environment that no present risk to the bathers s health, this work had as main objective to assess the influence of the PW s waters in the bathing water quality of the Pirangi beaches. To that end, were made collections of water in the beaches and in the rivers with the intention of quantify the fecal contamination indicators thermotolerant coliforms and enterococci, to then classify the conditions of bathing water quality according with the CONAMA Resolution number 274 of 2000. For the purposes greater knowledge about the health conditions of the Beaches Pirangi and about the influence the PW s waters exert on it, was done parallely to the study of the water quality, an investigation of the sand sanitary quality. Furthermore, it was made an evaluation of the PW s Water Quality through Water Quality Index (WQI). Starting from the results obtained in the research present was possible to verify, among other aspects, that the entry of the PW s waters in the Pirangi beaches exerts direct influence in the bathing water quality of the same ones, being the North Pirangi beach (point tracking PA-02) the most influenced. There was noticed also a significant reduction in the conditions of bathing water quality of the beaches in the rainy season. However, the precariousness do sewerage system of the Natal metropolitan region and the absence of a right system of treatment an final disposal of domestic sewage and industrial are the main factors responsi le for deterioration of the PW s Water Quality, and as a consequence, compromising the bathing water quality of the Pirangi beaches
Resumo:
Anthropic disturbances in watersheds, such as inappropriate building development, disorderly land occupation and unplanned land use, may strengthen the sediment yield and the inflow into the estuary, leading to siltation, changes in the reach channel conformation, and ecosystem/water quality problems. Faced with such context, this study aims to assess the applicability of SWAT model to estimate, even in a preliminary way, the sediment yield distribution along the Potengi River watershed, as well as its contribution to the estuary. Furthermore, an assessment of its erosion susceptibility was used for comparison. The susceptibility map was developed by overlaying rainfall erosivity, soil erodibility, the slope of the terrain and land cover. In order to overlap these maps, a multi-criteria analysis through AHP method was applied. The SWAT was run using a five year period (1997-2001), considering three different scenarios based on different sorts of human interference: a) agriculture; b) pasture; and c) no interference (background). Results were analyzed in terms of surface runoff, sediment yield and their propagation along each river section, so that it was possible to find that the regions in the extreme west of the watershed and in the downstream portions returned higher values of sediment yield, reaching respectively 2.8 e 5.1 ton/ha.year, whereas central areas, which were less susceptible, returned the lowest values, never more than 0.7 ton/ha.ano. It was also noticed that in the west sub-watersheds, where one can observe the headwaters, sediment yield was naturally forced by high declivity and weak soils. In another hand, results suggest that the eastern part would not contribute to the sediment inflow into the estuary in a significant way, and the larger part of the sediment yield in that place is due to anthropic activities. For the central region, the analysis of sediment propagation indicates deposition predominance in opposition to transport. Thus, it s not expected that isolated rain storms occurring in the upstream river portions would significantly provide the estuary with sediment. Because the model calibration process hasn t been done yet, it becomes essential to emphasize that values presented here as results should not be applied for pratical aims. Even so, this work warns about the risks of a growth in the alteration of natural land cover, mainly in areas closer to the headwaters and in the downstream Potengi River
Resumo:
Provide data and information on watershed becomes important since the knowledge of their physical characteristics, land use, etcetera, allows for better planning and sustainable use of economically, socially and environmentally in this area. The investigation of the physical environment has been commonly given with the use of geoprocessing, which has proved a very efficient tool. Within this context, this research aims at analyzing the river basin Punaú (located in the cities of Touros, Rio do Fogo and Pureza, state of Rio Grande do Norte) in several aspects, using geoprocessing as a tool of work, to provide information about the entire watershed. Specifically, this study aimed to update pre-existing maps, such as geological, geomorphological and land use, generating map of environmental vulnerability, under the aspect of erosion susceptibility of the area, generating map of legal incompatibility, identifying areas that are already being employed in breach of environmental legislation; propose solutions to the occupation of the river basin Punaú, focused on environmental planning. The methodology was based on the use of geoprocessing tools for data analysis and to make maps of legal incompatibility and environmental vulnerability. For the first map was taken into account the environmental legislation regarding the protection of watersheds. For the vulnerability analysis, the generated map was the result of crossing the maps of geology, geomorphology, soils and land use, having been assigned weights to different attributes of thematic maps, generating a map of environmental vulnerability in relation to susceptibility to erosion. The analysis results indicate that agriculture is the most significant activity in the basin, in total occupied area, which confers a high degree of environmental vulnerability in most of the basin, and some agricultural areas eventually develop in a manner inconsistent with Brazilian environmental legislation. It is proposed to consider deploying a measure of revitalization of the watershed in more critical areas and conservation through mitigation measures on the causes of environmental degradation, such as protection of water sources, protection and restoration of riparian vegetation, protection of permanent preservation areas, containment of erosion processes in general, and others listed or not in specific laws, and even the establishment of a committee of basins in the area
Resumo:
The reality of water resources management in semiarid regions, such as the Seridó region, has been shaped by a complex chain involving social-cultural, political, economic and environmental aspects, covering different spheres of activity - from local to federal. Because water is a scarce element, the most rational way pointed out by our recent history has been to move towards an increasing emphasis on the need for a truly rational, integrated, sustainable and participatory water resources management, supported by legislation and by a network of institutions that could materialize it. In this sense, despite all the advances in the formulation of public policies in water resources, which ones have indeed lead to significant changes that have occurred or are underway in semiarid regions such as Seridó? What factors may be preventing the realization of the desires rationality embedded in the framers of water policies intents? How to properly manage water resources if the current actors who promote their management and the political, human, cultural and institutional processes that intervene in this management, show strong traces of unsustainability? The research methodology adopted in this paper led to a breakdown of the traditional approach to water resource management, to integrate it into other areas of knowledge, especially to political science and public administration, catalyzed by the concept of "sustainable development". From a broad, interdisciplinary literature review, an exhaustive characterization of the river basin Seridó, a set of interviews with key people in the public administration acting in the region, a series of diagnoses and a set of propositions were made in order to correct the direction of current public policies for the region. From the point of view of public policies, it is in the deployment phase, not in its formulation, which lies a major problem of the lack of significant progress in water management. The lack of coordination between government programs are well characterized, as well as the lack of efficiency and effectiveness of their actions. The causes of this secular model are also discussed, including political factors and social relations of production, which led to a stalemate difficult, but of possible solution. It can be perceived there is a scenario of progressive deterioration of natural resources of the fragile ecosystem and a network of environmental and social consequences difficult to reverse, the result of a persistent and inertial sociopolitical culture, whose main factors reinforce itself. The work leads towards a characterization of the water resources management also from the perspective of environmental, institutional, political and human sustainability , the latter being identified, particularly as investment in the development of people as autonomous beings - not based in ideological directives of any kind - in the emancipation of the traditional figure of the poor man of the hinterland" to the "catalyst for change" responsible for their own decisions or omissions, based upon an education for free-thinking that brings each one as co-responsible epicenter of (self-) sustainable changes in their midst
Resumo:
One of the most important natural resources for sustaining human life, water, has been losing the basic requirements of quality and quantity sufficient enough to attend the population due to water contamination'problems, often caused by human beings themselves. Because of this, the sources of this resource are often located in remote places of the natural environment to ensure the quality of the water. However, when urban expansion began to occupy these areas, which were once regarded as distant, environmental pollution problems began to occur due to occupation of the land without planning. Based on this occurrence, this study aims to propose environmental zoning for the Maxaranguape river watershed in order to protect its water resources. This is important because this river can serve as a source of supply for the metropolitan area of Natal, the capital of Rio Grande do Norte. In accordance to this proposition, the model of natural soil loss vulnerability (CREPANI et al., 2001), the model of aquifer pollution vulnerability (FOSTER et al., 2006), and the legal incompatibility map (CREPANI et al., 2001) were used to delimit the zones. All this was done with Geographic Information System (GIS) and also created a geographic database update of the basin. The results of the first model mentioned indicated that 63.67% of the basin was classified as moderately stable / vulnerable, 35.66% as moderately vulnerable, and 0.67% as vulnerable. The areas with high vulnerability degree correspond with sand dunes and river channels areas. The second model indicated that 2.84% of the basin has low vulnerability, 70.27%) has median vulnerability, and 26.76% and 0.13% has high vulnerability and extreme vulnerability, respectively. The areas with the highest vulnerability values also refer to part of the sand dunes and river channels besides other areas such as Pureza urban area. The legal incompatibility map indicated that the basin has 85.02 km2 of Permanent Protection Area (PPA) and 14.62% of this area has some incongruity of use. Based on these results it was possible to draw three main zones: Protection and Sustainable Use Zone (PSUZ), Protection and Environmental Restoration Zone (PERZ) and Environmental Control Zone, which are divided into A, B and C. The PSUZ refer to the coastal areas of the basin, where the sand dunes are located. These sites should be areas of environmental protection and of sustainable urban expansion. The ZPRA refer to river channels, which are in high need of rehabilitation. The third zone corresponds to the rest of the basin which should have, in general, the mapping of possible sources of contamination for further control on the use and occupation of the river
Resumo:
Urban centers in Pitimbu Watershed use significant groundwater sources for public supply. Therefore, studies in Dunas Barreiras aquifer are relevant to expand knowledge about it and help manage water resources in the region. An essential tool for this management is the numerical modeling of groundwater flow. In this work, we developed a groundwater flow model for Pitimbu Watershed, using the Visual Modflow, version 2.7.1., which uses finite difference method for solving the govern equation of the dynamics of groundwater flow. We carried out the numerical simulation of steady-state model for the entire region of the basin. The model was built in the geographical, geomorphological and hydrogeological study of the area, which defined the boundary conditions and the parameters required for the numerical calculation. Owing to unavailability of current data based on monitoring of the aquifer it was not possible to calibrate the model. However, the simulation results showed that the overall water balance approached zero, therefore satisfying the equation for the three-dimensional behavior of the head water in steady state. Variations in aquifer recharge data were made to verify the impact of this contribution on the water balance of the system, especially in the scenario in which recharge due to drains and sinks was removed. According to the results generated by Visual Modflow occurred significantly hydraulic head lowering, ranging from 16,4 to 82 feet of drawdown. With the results obtained, it can be said that modeling is performed as a valid tool for the management of water resources in Pitimbu River Basin, and to support new studies
Resumo:
This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acauã a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acauã of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil.
Resumo:
The problems of water supply in Northeast Brazil are severe and require more focused studies. This work was intended to assess water quality in the watershed Pirangi, located in the Northeastern state of the newborn using the Water Quality Index, AQI associated with the Index of Toxicity-IT. The data presented in this study were collected in November 2008, June 2009 and March 2010 at eight sampling stations distributed throughout the basin. The study covered nine parameters, based on guidelines established by CETESB, and seven members of Metal Toxicity index-IT. These waters are framed in the classification between GOOD and BAD showing AQI 41.34 minimum and a maximum of 76.23. Virtually all seven metals analyzed were below the detection limits of ICP-OES giving IT a water equal to one when they are absent and 0 when there are levels of trace metals
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