CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Esta pesquisa foi desenvolvida no municÃpio de TianguÃ, Cearà e constou de trÃs etapas. Na primeira, foi realizado o estudo qualitativo e quantitativo da contaminaÃÃo da Ãgua subterrÃnea, pertencente ao AqÃÃfero Serra Grande, por pesticidas e nitrato a partir do monitoramento de uma bateria de poÃos. Os pesticidas analisados foram: atrazina, simazina e metil paration. Na segunda etapa, foi avaliada a vulnerabilidade do aqÃÃfero aplicando os Ãndices DRASTIC e DRASTIC pesticidas associados Ãs tÃcnicas de Sistema de InformaÃÃo GeogrÃfica. Finalmente, na terceira etapa, foi realizada anÃlise multivariada das medidas de pesticidas e nitrato a partir da aplicaÃÃo do mÃtodo de classificaÃÃo hierÃrquica de Ward e correlacionada com as classes de vulnerabilidade delineadas nos mapas DRASTIC e DRASTIC pesticidas. As determinaÃÃes dos pesticidas atrazina, simazina e metil paration durante a etapa qualitativa, indicaram que do total de 153 amostras analisadas foi constatada a presenÃa desses compostos em 126 amostras (82%). Na etapa quantitativa, do total de 36 amostras analisadas para cada composto, verificou-se que atrazina, simazina e metil paration foram detectados em, respectivamente, 17 amostras (47%), 21 amostras (55%) e 14 amostras (39%) em desacordo com o VMP definido na legislaÃÃo. O nitrato foi detectado nos 31 poÃos monitorados e apresentou, com exceÃÃo de um poÃo, concentraÃÃes mÃdias de acordo com o limite definido na legislaÃÃo. O Ãndice DRASTIC agrupou quatro classes de vulnerabilidade: insignificante, muito baixa, baixa e moderada, predominando a classe muito baixa (628,7 km2 ou 67,2%). O Ãndice DRASTIC pesticidas indicou cinco classes de vulnerabilidade: muito baixa, baixa, moderada, alta e muito alta, predominando a classe moderada (553,2 km2, ou 59,1 %). As medidas dos pesticidas e nitrato foram agrupadas nos grupos I, II e III levando em consideraÃÃo o nÃvel de contaminaÃÃo da Ãgua subterrÃnea. Constatou-se correlaÃÃo para a maioria dos grupos, tanto para as medidas de pesticidas quanto para nitrato, com as classes de vulnerabilidade dos Ãndices DRASTIC e DRASTIC pesticidas. / This research was developed in the city of TianguÃ, Cearà and consisted of three stages. In the
first one, the investigation and quantitative study on the contamination of the groundwater
was carried out in the Serra Grande aquifer, focusing on pesticides and nitrate by monitoring a
cluster of wells. The pesticides analyzed were atrazine, simazine and methyl parathion. In the
second stage, the vulnerability of the aquifer was evaluated applying DRASTIC and
DRASTIC pesticide indexes combined together with the Geographic Information System
(GIS) technique. Finally, in the third stage, a multivariate analysis of pesticides and nitrate
concentrations was conducted through the application of the hierarchic classification method
of Ward and correlating with the vulnerability classification defined in DRASTIC and
DRASTIC pesticide maps. In the investigation study for the pesticides atrazine, simazine and
methyl parathion, 153 samples were analyzed and those compounds were found in 82% of
samples (126 of the total). In the quantitative stage 36 samples were analyzed for each
compound. Atrazine, simazine and methyl parathion were detected in, respectively, 17
samples (47%), 21 samples (55%) and 14 samples (39%) in disagreement with the maximum
allowed concentration (MAC) established by the legislation. Nitrate was detected in 31 wells
monitored and presented, with the exception of one well, average concentrations in
accordance with the limit established by the legislation. In this study the DRASTIC index
grouped four classes of vulnerability: insignificant, very low, low and moderate. The very low
class predominated, representing 628.7 km2 or 67.2%. The DRASTIC pesticides index
indicated five classes of vulnerability: very low, low, moderate, high and very high. The
predominant class was moderate, representing 553.2 km2 or 59.1% of the wells. Pesticides
and nitrate measures were grouped into groups I, II and III taking into consideration the level
of contamination of the groundwater. A correlation for the majority of the groups for both
pesticides and nitrate was found, according to the vulnerability classes found in DRASTIC
and DRASTIC pesticide indexes.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:381 |
| Date | 01 September 2006 |
| Creators | Francisco MaurÃcio de SÃ Barreto |
| Contributors | Jose Carlos de AraÃjo |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Engenharia Civil, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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