Impactos da ocupação urbana e qualidade das águas superficiais na microbacia da Va-de-Cães (Belém/PA)

Abstract

The hidrografic basin of Val-de-Cães, with 10,10Km2, situated in the portion north of the City of Belém, presents as characteristic the dense urban occupation, represented for clandestine occupations, joint residential and for institucional areas. The present study it analyzes the impacts proceeding for the main forms from occupation and use of the basin of Val-de-Cães, using as indicating the quality of superficial waters of the hidric body. The analyses of waters had been carried through in two periods, rainy (February) and a other dry one (August), being determined the following parameters: turbidez, condutividade, color, pH, Dissolved Oxygen, nitrogenados components, temperature, Demand Biochemist of Oxygen, metals, oils and greases and total and fecais coliformes. The water of the narrow river disclosed values raised in downstream of the narrow river, possibly for the direct influence of the bay one of the Guajará, for pH, oils and greases, coliformes and Demand Biochemist of Oxygen. In the spring the parameters of total coliformes and Demand Biochemist of Oxygen present values that are considered raised in relation to the too much points of collection, but are the palafitas place that presents considerable number in the neighborhoods and little vegetation. The presence of effluent domestic servants and sewers is portraied mainly by the amount of coliformes, oils and greases, turbidez and text of match in the samples collected in both the periods and for the great number of dump points that increase to each day.