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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Resist?ncia ao fluxo devido a vegeta??o num trecho do Rio Pitimbu, Natal-RN / Resistance to flow due to vegetation in a stretch of the river Pitimbu River, Natal-RN

Vitorino, Camila Farias 29 August 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:58:35Z No. of bitstreams: 1 CamilaFariasVitorino_DISSERT.pdf: 3139331 bytes, checksum: 6243889fc2732b28569d94a68c92cb15 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-08T23:08:15Z (GMT) No. of bitstreams: 1 CamilaFariasVitorino_DISSERT.pdf: 3139331 bytes, checksum: 6243889fc2732b28569d94a68c92cb15 (MD5) / Made available in DSpace on 2017-11-08T23:08:15Z (GMT). No. of bitstreams: 1 CamilaFariasVitorino_DISSERT.pdf: 3139331 bytes, checksum: 6243889fc2732b28569d94a68c92cb15 (MD5) Previous issue date: 2017-08-29 / A vegeta??o macr?fita possui um papel importante na manuten??o e equil?brio dos ambientes aqu?ticos em rios e lagos nas regi?es tropicais. Em cursos d??gua de pequeno porte, essas plantas proporcionam benef?cios ecol?gicos, pois atuam na sedimenta??o e reten??o de nutrientes, propiciando melhoria nas propriedades f?sico-qu?micas da ?gua. A presen?a de macr?fitas na calha fluvial alteram o comportamento da velocidade e aumentam a resist?ncia ao fluxo, com redu??o da velocidade na se??o e aumento da profundidade. Em geral, o retardamento do escoamento est? associado a fen?menos indesej?veis, tais como inunda??o de ?reas ocupadas. O objetivo deste estudo foi investigar o comportamento da resist?ncia ao fluxo provocado pela presen?a de vegeta??o macr?fita r?gida emersa da esp?cie Aninga (Montrichardia linifera) num trecho do rio Pitimbu situado na regi?o metropolitana de Natal. Para isso foram realizadas duas campanhas hidrom?tricas, realizadas em 12/04/2017 e 15/09/2017. A metodologia empregada consistiu na medi??o de vari?veis hidr?ulicas e levantamento in situ das caracter?sticas da vegeta??o no trecho e analise da intera??o fluxo-vegeta??o. A analise da vegeta??o envolveu a delimita??o de quatro quadrantes (4 m2) definidos aleatoriamente na ?rea de estudo. Nesses quadrantes foram levantadas as caracter?sticas morfol?gicas das plantas e a distribui??o espacial. A medi??o das vari?veis hidr?ulicas foi feita com a discretiza??o das se??es transversais em verticais, onde foram medidas as velocidades medias pontuais. A vaz?o e o numero de Manning obtidos nas campanhas 1 e 2 foram 0,2467 m?/s e 0,069 m-1/3s; 0,2076 m?/s e 0,078 m-1/3s respectivamente. A densidade da distrbui?ao espacial da vegeta??o era 8,12 plantas/m2. O comportamento da velocidade na se??o S1 demonstrou alta variabilidade espacial, com alguns valores acima da m?dia. Esse comportamento estava associado a presen?a de vegeta??o. Foram registradas velocidades negativas em algumas regi?es a jusante das plantas, indicando a gera??o de esteiras e fluxo reverso nestes locais. O padr?o de distribui??o espacial da vegeta??o era agregado em algumas regi?es da comunidade de plantas. A intera??o fluxo-vegeta??o foi analisada a partir de uma sequ?ncia de registros fotogr?ficos. Foi poss?vel identificar o comportamento dos fluxos atrav?s das plantas: regi?es de descolamento da camada limite, regi?es de esteira e de forma??o de v?rtices. / Macrophyte vegetation plays an important role to keep balanced aquatic environments in rivers and lakes in tropical regions. In small water courses, these plants provide ecological benefits since they act on sedimentation and nutrients retention, leading to an improvement in the water physicochemical properties. The presence of macrophytes in the river channel changes the velocity behaviour and increases the resistance to flow, causing reduction in speed and increase of depth in the section. Generally, flow retardation is associated to unwanted events, such as flooding of occupied areas. The aim of this study was to investigate the hydraulic resistance behaviour to flow caused by the presence of rigid and emersed macrophyte vegetation of the species Aninga (Montrichardia linifera) in a section into Pitimbu River located in the metropolitan region in Natal. Two hydrometric campaigns were carried out on 04/24/2017 and 09/15/2017. The methodology used included measurement of hydraulic variables, in situ survey of vegetation characteristics and analysis of the flow-vegetation interaction. Vegetation analysis involved the delimitation of three quadrants (4 m2) defined in the study area. In these quadrants, the morphological characteristics of the plants and the spatial distribution were raised. The hydraulic variables were measured with the discretization of the cross sections in verticals, where the average speeds were measured. Manning flow and number obtained in campaigns 1 and 2 were 0.2467 m?/s and 0.069 m-1/3s; 0.2076 m?/s and 0.078 m-1/3s s respectively. The density of the spatial distribution of vegetation was 8.12 plants / m2. The velocity behavior in section S1 showed high spatial variability, with some values above average. This behavior was associated with the presence of vegetation. Negative velocities were recorded in some regions downstream of the plants, indicating the generation of mats and reverse flow at these sites. The pattern of spatial distribution of vegetation was aggregated in some regions of the plant community. The flow-vegetation interaction was analyzed from a sequence of photographic records. It was possible to identify the behavior of the flows through the plants: regions of boundary layer detachment, belt regions and vortex formation.
2

O papel da macr?fita aqu?tica emersa Montrichardia linifera (Araceae) na ciclagem de f?sforo e na bioacumula??o de metais pesado em um sistema fluvial sob efeitos da urbaniza??o / The role of the emerged aquatic macrophyte Montrichardia Linifera (Araceae) in phosphorus cycling and heavy metals bioaccumulation in the watershed under urbanization effects

Silv?rio, J?ssica Mitizy de Oliveira 08 May 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-03T13:47:46Z No. of bitstreams: 1 JessicaMitizyDeOliveiraSilverio_DISSERT.pdf: 4111576 bytes, checksum: 65635da2847b2131a73ea2226df25e1e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-07T13:47:25Z (GMT) No. of bitstreams: 1 JessicaMitizyDeOliveiraSilverio_DISSERT.pdf: 4111576 bytes, checksum: 65635da2847b2131a73ea2226df25e1e (MD5) / Made available in DSpace on 2017-07-07T13:47:25Z (GMT). No. of bitstreams: 1 JessicaMitizyDeOliveiraSilverio_DISSERT.pdf: 4111576 bytes, checksum: 65635da2847b2131a73ea2226df25e1e (MD5) Previous issue date: 2017-05-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A urbaniza??o normalmente est? associada a polui??o dos corpos h?dricos por nutrientes e metais pesados. Na busca por t?cnica de biomonitoramento e m?todos de tratamento da polui??o ambiental, o uso de macr?fitas aqu?ticas emergentes tem apresentado bons resultados como bioindicadoras ecol?gicas, al?m de fitodepuradoras e fitorremediadoras em sistemas fluviais, devido ? sua efici?ncia, praticidade, alta sensibilidade e baixo custo para remo??o destes contaminantes . As plantas macr?fitas aqu?ticas normalmente ocorrem nas zonas de transi??o solo-?gua, onde poluentes dissolvidos na ?gua e no sedimento s?o submetidos ? a??o depuradora dessas plantas, dando origem a rea??es bioqu?micas e f?sicas que modificam a qualidade do sistema aqu?tico. Este trabalho teve como objetivo principal avaliar a interfer?ncia da macr?fita aqu?tica emersa Aninga (Montrichardia linifera, Araceae) visando o conhecimento da capacidade de resposta de forma mensur?vel desta esp?cie ? perturba??o ambiental por contamina??o de elementos-tra?os e nutrientes em um sistema natural l?tico eutrofizado de clima tropical. A partir dos resultados obtidos neste estudo atrav?s de monitoramento vari?veis f?sico-qu?micas limnol?gicas e an?lises de mecanismos de bioacumula??o e transloca??o na planta, constatou-se que se trata de uma esp?cie bioindicadora para elementostra?os e que possui potencial de fitorremedia??o para o nutriente f?sforo e metais Alum?nio, Chumbo, Ferro . Tamb?m evidenciou que as comunidades de Aningais inferem de forma positiva na fun??o ecol?gica da din?mica as fra??es do nutriente f?sforo no sedimento e atua como biofiltradora na coluna d??gua no trecho estudado. / Urbanization is usually associated with pollution of water bodies by nutrients and heavy metals. In the search for biomonitoring techniques and environmental pollution treatment methods, the use of emergent aquatic macrophytes has shown good results as ecological bioindicators, as well as phytodeurants and phytoremediation in river systems, due to their efficiency, practicality, high sensitivity and low cost. Removal of these contaminants. Aquatic macrophyte plants usually occur in soil-water transition zones, where pollutants dissolved in water and sediment are subjected to the purifying action of these plants, giving rise to biochemical and physical reactions that modify the quality of the aquatic system. The objective of this work was to evaluate the interference of the emergent aquatic macrophyte Aninga (Montrichardia linifera, Araceae) aiming the knowledge of the measurable response capacity of this species to the environmental disturbance due to contamination of trace elements and nutrients in a natural eutrophic lotic system tropical weather. From the results obtained by monitoring limnological physico-chemical variables and analysis of mechanisms of bioaccumulation and translocation in the plant, it was verified that it is a bioindicator species for trace elements and that it has phytoremediation potential for the nutrient phosphorus and metals Aluminum, Lead, Iron. It also showed that the communities of Aningais positively infer in the ecological function of the dynamics the fractions of the nutrient phosphorus in the sediment and acts as a biofilter in the water column in the studied section.

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