Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-14T20:26:09Z No. of bitstreams: 1 RadmilaSalvianoFerreira_DISSERT.pdf: 3222276 bytes, checksum: 685843641bfc9209a45b900b9eb482ab (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-16T00:03:57Z (GMT) No. of bitstreams: 1 RadmilaSalvianoFerreira_DISSERT.pdf: 3222276 bytes, checksum: 685843641bfc9209a45b900b9eb482ab (MD5) / Made available in DSpace on 2016-06-16T00:03:57Z (GMT). No. of bitstreams: 1 RadmilaSalvianoFerreira_DISSERT.pdf: 3222276 bytes, checksum: 685843641bfc9209a45b900b9eb482ab (MD5) Previous issue date: 2015-12-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Reservat?rios s?o ecossistemas artificiais intermedi?rios entre rios e lagos amplamente utilizado no semi?rido brasileiro como forma de suprir a escassez h?drica da regi?o. A utiliza??o da ?gua destes mananciais para m?ltiplos usos associada ao uso e ocupa??o sem manejo adequado da zona rip?ria influenciam diretamente no aumento do aporte de nutrientes para os ambientes aqu?ticos contribuindo para a acelera??o da eutrofiza??o. A regi?o semi?rida ? marcada por condi??es meteorol?gicas peculiares como alta evapora??o, temperaturas elevadas com pouca varia??o ao longo do ano e longo tempo de resid?ncia da ?gua, suscet?vel a eventos de seca prolongada, o que tende a concentrar os nutrientes nos reservat?rios favorecendo o estabelecimento de condi??es eutr?ficas. Al?m disso, ? comum o uso e ocupa??o do solo com o desenvolvimento de atividades com potencial impacto ambiental sobre os recursos naturais como agricultura, pecu?ria e a aus?ncia de esgotamento sanit?rio. O objetivo desse trabalho ? avaliar a qualidade da ?gua do Reservat?rio Cruzeta, localizado na regi?o semi?rida do Rio Grande do Norte, num per?odo de seca prolongada e avaliar a qualidade do solo sob diferentes usos na sua zona rip?ria, ambos atrav?s do monitoramento de vari?veis f?sico-qu?micas. O per?odo de seca prolongada foi acompanhado de altos n?veis de turbidez, s?lidos suspensos, nutrientes e clorofila a caracterizando baixa qualidade da ?gua. Na zona rip?ria do reservat?rio Cruzeta as ?reas sob uso da agropecu?ria mostraram-se como uma das principais fontes difusas de nutrientes para o reservat?rio, apresentando os maiores teores de f?sforo e nitrog?nio no solo derivados da decomposi??o das excretas animais e do uso de fertilizantes conferindo ao manancial uma tend?ncia ao aumento do processo de eutrofiza??o. Os indicadores de qualidade da ?gua e do solo s?o ?teis para monitoramento e avalia??o do estado de conserva??o desses recursos naturais permitindo o controle e mitiga??o do processo de eutrofiza??o do reservat?rio. Assim, este estudo corroborou a hip?tese de que a redu??o do n?vel d??gua, resultante do evento da seca prolongada, agrava os sintomas da eutrofiza??o e a utiliza??o do solo sob os diversos usos modifica os atributos f?sicos e qu?micos do solo sendo a pecu?ria e a agricultura os usos com maior potencial em ceder P e N para o ambiente aqu?tico. / Reservoirs are artificial ecosystems intermediate between rivers and lakes widely used in the Brazilian semiarid region as a way to provide water supply due to the said region?s water scarcity. The use of water from these supply sources for multiple uses, along with occupation and utilization of its riparian zone without proper management, directly influences the increased nutrient flow into aquatic environments, there with contributing to the acceleration of eutrophication. The semi-arid region is characterized by peculiar weather conditions, such as severe evaporation, high temperatures with little variation throughout the year and long water residence time, making it susceptible to prolonged drought occurrence, which tends to concentrate the nutrients in reservoirs, which favors the development of eutrophic conditions. Moreover, it is common soil use and occupation by carrying out activities with potential environmental impact on natural resources such as agriculture, livestock farming and lack of sanitation. The aim of this study is both to evaluate the water quality of the Cruzeta Reservoir, located in the semiarid region of Rio Grande do Norte, during a prolonged drought period, and assess the quality of its riparian zone soil under different uses, by monitoring physical-chemical variables. Along the prolonged drought, high levels of turbidity, suspended solids, nutrients and chlorophyll a were verified as present, therefore featuring low water quality. In the riparian zone of Cruzeta Reservoir, the areas under use of agriculture and livestock farming appeared as one of the main diffuse sources of nutrients to the said reservoir, featuring the highest levels of phosphorus and nitrogen in the soil, originated from decomposition of animal excreta and from the use of fertilizers, creating a tendency to increased eutrophication of such water supply source. The indicators of water and soil quality are useful for monitoring and evaluating the conservation status of natural resources, allowing the control and mitigation of the reservoir eutrophication process. This study confirmed the hypothesis that the reduction of water level, resulting from prolonged drought event, aggravates the symptoms of eutrophication; and also that using the soil under severalways modifies the physic chemical properties of the soil, having livestock farming and agriculture as the usages with greatest potential towards yielding P and N to the aquatic environment.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T14:44:41Z No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-14T20:07:28Z (GMT) No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) / Made available in DSpace on 2018-03-14T20:07:28Z (GMT). No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) Previous issue date: 2017-11-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Em regi?es mais secas, muitos reservat?rios chegam a volumes t?o baixos que deixam de ser suficientes para abastecimento, sendo assim interrompida a tomada d??gua. No semi?rido brasileiro ? recorrente o esgotamento h?drico em alguns reservat?rios, os quais permanecem secos por meses ou at? anos, o que representa um problema para o abastecimento e causa preju?zos socioecon?micos. Ap?s um evento de esgotamento h?drico, em termos de impactos na qualidade da ?gua, espera-se que haja melhorias ap?s a renova??o com novas ?guas: Menor biomassa algal, maior transpar?ncia da ?gua, menor turbidez e baixa concentra??o de nutrientes. O objetivo deste estudo foi analisar a qualidade da ?gua de um reservat?rio do semi?rido tropical ap?s esgotamento h?drico durante um evento de seca prolongada. O reservat?rio estudado foi Dourado, localizado semi?rido brasileiro. O trabalho foi realizado com tr?s per?odos distintos, determinados de acordo com o volume h?drico. Os per?odos foram marcados por chuvas abaixo da m?dia hist?rica anual, estando assim inseridos em um per?odo de estiagem prolongada. Foram analisadas as vari?veis transpar?ncia da ?gua, turbidez, condutividade el?trica, pH, f?sforo total, f?sforo reativo dissolvido e clorofila-a. Ap?s a renova??o das ?guas, a expressiva redu??o na clorofila-a, indicativa de biomassa algal, indica melhora na qualidade da ?gua em termos de eutrofiza??o, devido ? mudan?a de estado de trofia de eutr?fico para mesotr?fico. As vari?veis pH, condutividade el?trica e turbidez tamb?m sofreram redu??o ap?s a renova??o das ?guas. N?o houve redu??o ap?s o aporte de ?gua para as vari?veis f?sforo total e f?sforo reativo dissolvido em compara??o aos per?odos anteriores. / In dry regions, many reservoirs reach volumes so low that they are no longer sufficient for supply, interrupting the water intake. In the Brazilian semi-arid region, occasional drying is recurrent in some reservoirs, which remains dry for months or even years, representing a problem for the supply and causing socioeconomic issues. After an event of drying, in terms of impacts on water quality, it is expected that there will be improvements after reflooding: Less algal biomass, increased water transparency, decreased turbidity and low concentration of nutrients. The aim of this study was to analyze the water quality of a tropical semi-arid reservoir after drying during an extended drought event. The studied reservoir was Dourado, located in the Brazilian semi-arid. This study consists of the comparison of three distinct periods accordingly to the water volume. Those periods were marked by rainfall below the annual historical average, therefore being inserted in an extended drought period. The variables water transparency, turbidity, electrical conductivity, pH, total phosphorus, soluble reactive phosphorus and chlorophyll-a were analyzed. After the water renewal, a significant reduction in chlorophyll-a, indicative of algal biomass, indicates an improvement in water quality in terms of eutrophication, due to the change of the trophic state from eutrophic to mesotrophic. pH, electrical conductivity and turbidity variables also reduced after the reflooding, indicating an improvement in water quality. There was no reduction in total phosphorus and soluble reactive phosphorus after the reflooding in comparison to the previous periods.