Multivariate Analysis for selection of monitoring parameters in water reservoir of Juiz de Fora, Minas Gerais

Abstract The need to control land use and monitor water quality for public supply requires the evaluation of many parameters, which are often difficult to analyze and interpret due to cost and the large volume of data. In this context, this work selected the most relevant parameters for monitoring the Dr. João Penido Dam, the main supply source of Juiz de Fora, MG. The evaluation was conducted based upon a series of thirteen parameters of the catchment provided monthly by the Municipal Sanitation Company between 1998 and 2012. The data were statistically processed using Factor Analysis and Principal Component Analysis and parameters with highest variances were extracted. Component 1 (FV1) reflected the influence of dissolved solids associated with runoff processes in the watershed and with the erosion of margins. FV2, as well as FV3, are strongly associated to the potential discharge of sewage in the watershed area. Using multivariate analysis, we removed five parameters that showed no variance: hardness, consumed oxygen, pH, alkalinity and manganese.