EXPANSÃO DA AGRICULTURA IRRIGADA E MUDANÇAS NOS PROCESSOS DE INTERAÇÃO SUPERFÍCIE-ATMOSFERA: UM ESTUDO NUMÉRICO DE IMPACTO AMBIENTAL EM ÁREAS DE CAATINGA (EXPANSION OF IRRIGATED AGRICULTURE AND CHANGES IN PROCESSES OF SURFACE-ATMOSPHERE INTERACTION: A NUM

E crescente a preocupacao com a poluicao dos recursos hidricos, principalmente sobre as aguas destinadas ao abastecimento publico. Nos ecossistemas aquaticos, alem do processo de eutrofizacao, outros fatores como a sazonalidade favorecem a quebra do equilibrio ecologico. A presente pesquisa verificou a influencia da sazonalidade na ocorrencia de cianobacterias como parâmetro da qualidade da agua do reservatorio Mororo, situado no municipio de Pedra (Pernambuco, Brasil). As caracteristicas fisico-quimicas estudadas foram: cor aparente, turbidez, pH e fosfato total. As cianobacterias estiveram representadas por 10 generos, distribuidos entre 4 ordens e 4 familias. Destacam-se Planktothrix Anagnostidis & Komarek, Aphanocapsa Nageli, Dolichospermum Bory ex Bornet et Flahault e Cylindrospermopsis Seenayya et Subba Raju por serem potencialmente toxicas. Os resultados mostraram densidades de cianobacterias acima dos limites estabelecidos pela Resolucao no 357/2005 do CONAMA. O reservatorio foi considerado supereutrofico durante todo o estudo. Os resultados indicaram a influencia da sazonalidade na qualidade da agua, em funcao da pluviosidade na dinâmica das variaveis limnologicas, em especial quanto a disponibilidade e diluicao de nutrientes nos reservatorios. Normal 0 21 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; color:black; mso-themecolor:text1; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} ABSTRACT There is growing concern about the pollution of water resources, especially on the water for public supply. In aquatic ecosystems, in addition to the eutrophication process, other factors such as seasonality favor the breakdown of ecological balance. This research analyzes the influence of seasonality in the occurrence of cyanobacteria and water quality of the Mororo reservoir, located in the city of Pedra, (Pernambuco, Brazil). The physicochemical parameters studied were: apparent color, turbidity, pH and total phosphate. Cyanobacteria were represented by 10 genera, distributed among four orders and four families. Planktothrix Anagnostidis & Komarek , Aphanocapsa Nageli, Dolichospermum Bory ex Bornet et Flahault and Cylindrospermopsis Seenayya et Subba Raju are highlighted for being potentially toxic. The results showed densities of cyanobacteria above the limits established by CONAMA Resolution No. 357/2005. The reservoir was considered in supereutrophic state throughout the study. The results showed the influence of seasonality on water quality, depending on the rainfall in the dynamics of limnological variables, especially for availability and dilution of nutrients in the reservoirs. Keywords: reservoirs, cyanobacteria, public water supply, water quality .