ANÁLISE ESTATÍSTICA MULTIVARIADA DE PARÂMETROS FÍSICO-QUÍMICOS E MICROBIOLÓGICOS E CÁLCULO DO ÍNDICE DE QUALIDADE DE ÁGUA (IQA) DA LAGOA DE CIMA, CAMPOS DOS GOYTACAZES/RJ

Multivariate statistical analysis of physico-chemical and microbiological parameters and calculation of the Water Quality Index (NSFWQI) of "Lagoa de Cima", Campos dos Goytacazes/RJ

Abstract

This article aimed to make a spatio-temporal characterization of the water quality of “Lagoa de Cima”, Campos dos Goytacazes/RJ, Brazil, through NSFWQI and multivariate statistical analysis of parameters that compose it. Water samples were collected in two field trips, where six points were located at the lagoon, one point at the Imbé river and one point at the Urubu river, its tributaries. The physical-chemical analyses were carried out at the LabFoz, laboratory of the Polo de Inovação Campos dos Goytacazes/IFFluminense. The NSFWQI was calculated in an Excel spreadsheet, using the weighted average and weighted product formula. The first field trip (S1) happened on April 16, 2019, the accumulated precipitation in the previous 30 days of 40 mm, where almost all points indicated “good” quality, except one point that presented “medium” when the weighted product was used. The second field trip (S2) occurred on October 01, 2019, where the accumulated precipitation in the previous 30 days was 72.8 mm. This one presented better results, between “excellent” and “good”, and two points with “medium” quality. The greater volume of water due to rains may have contributed to the improvement of water quality, because there is a greater dissolution in the pollutant load.