Diagnóstico ambiental dos Rios da Prata e Catumbi e balneabilidade da praia: estudo de caso em Muriqui, Mangaratiba RJ.

Abstract

The uncontrolled exploration of the wather has been compromised its quality and quantity for several uses, among which the primary contact recreational usage can be highlighted. This study brings a common problem in the brazilian coast: cities that receive a high number of visitors during some periods of the year and suffer environmental crisis due the drastic change of population volume, since the floating population difficults the public input management like the water supplying, health services, waste discard and the sewerage system treatment, which can pollute these areas. Muriqui resort, a city in Mangaratiba, in Rio de Janeiro State, was chosen as a model for this study, which object was to diagnose the hydric pollution and the balneability of the beach. The methodology of the exploration was based into reviewing scientifcs publications, books and legal material and creating a sampling plan. . Besides, some municipal departaments were visited so as to collect present data about the city and, in order to confront the water analysis, an investigation of the rain history of the area was made . Aiming toverify the beach and two rivers water quality, samples were collected twice a month on mondays mornings, from september 2012 to august 2013, totalizing 25 collects. In each collect, five sampling poins were made: three points at the beach, one at Prata s river and other at Catumbi river. Physical, chemical and biological parameters were monitored, in order to compare these data with the numbers alowed by law and correlating them to verify the degradation level of the water. The results of this study demonstrate that the point of Prata s river was the most degradated, because it was the nearest point of the river s mouth. The assessment of the beach water quality indicated that the site had excellent balneability during 96% of the monitored period, and it was improper only once. During the study some parameters show pollution promoted by domestic effluents, apparently in initial degradation.