Influência do uso e da ocupação do solo na qualidade da água e capacidade autodepurativa do Rio Pomba

• Ano de defesa: 2009
• Autor(a) principal: Farage, José de Alencar Pinto
• Orientador(a): Matos, Antonio Teixeira de
• Banca de defesa: Martinez, Mauro Aparecido , Monaco, Paola Alfonsa Vieira Lo , Oliveira, Rubens Alves de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Engenharia Agrícola
• Departamento: Construções rurais e ambiência; Energia na agricultura; Mecanização agrícola; Processamento de produ
• País: BR
• Palavras-chave em Português: Qualidade da água; Autodepuração; Rio Pomba; Ocupação do solo
• Palavras-chave em Inglês: Water quality; Self-depuration; Rio Pomba; Occupation of the soil
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENGENHARIA DE AGUA E SOLO
• Link de acesso: http://locus.ufv.br/handle/123456789/3546

The River Pomba hydrographic basin is an intensely occupied area which has been suffering constant anthropic interference and this leads to an advanced state of degradation. The main characteristics of the basin are, under the environmental point of view, lack of treated sewage and the degradation of the plant coverage, which potentiate the transport of sediments towards the river flow. Therefore, a study with samples divided into four stages was made in order to relate the water quality to the type of its use and the occupation of the soil. This study enabled the assessment of the interactions between the anthropic interference and the water resources of the River Pomba basin. During the rainy and the dry seasons, the Water Quality Level (IQA), the Trophic State Level (IET), the deoxygenation (K1) and the reparation coefficients (K2) were determined by the samples found in nine spots along the river. Among the assessed spots it was possible to observe that during the drought the River Pomba was partially eutrophied with the IET levels between 40 and 69 in some spots along the assessed area. On the other hand, during the rainy season all the spots were eutrophied, presenting IET between 60 and 87. Such an increase was due to the presence of phosphorus in the rail river, because of the superficial flow in the rainy season. As for the IQA, it has been registered that in the high parts of the River Pomba, the values ranged from 59 to 75 (Average to Good concepts), both during the rainy season and the drought. In the middle of the river, though, the water quality got worse, Average to Bad (69 to 40) due to the more populated tows. However, it was possible to observe that, in the downstream of the tows Dona Euzébia and Cataguases, in the middle of the river, the concept was Good (71 and 72) showing the water self-depurative capacity (K2 equals 0,69 d-1). In general, the IQA values had better concepts in the drought than during the rainy season in the several assessed spots of the River Pomba. The analysis of the water samples indicated a tendency to hypereutrophication. The K1 values are close to the typical values for crystal-clear waters with an input of organic material of low degradabilityin the water. The values of K2, which were found during the drought, for the spots I and II, were within the typical limits for rivers with ordinary speed and spot III was within the typical limits for slow rivers. During the rainy season the values were higher than the ones during the drought, being such values typical of the rapids in the spots I and II and typical values of fast rivers in spot III, what gives this body of water a high ability to depurate organic materials.