Chemometrics Applied in the Development of a Water Quality Indicator System for the Brazilian Amazon.

The objective of this work was to develop a method to calculate the water quality index (WQI) using chemometric methods. The study was carried out at the Curua-Una hydroelectric power plant in the state of Para in the Brazilian Amazon. Eight collection stations in four periods (winter, intermediate I, summer, and intermediate II) and 29 parameters were selected. Multivariate analysis was applied to the results to verify the quality of the data and to select the most sensitive variables to be used as indicators for the WQI calculation. The 10 parameters selected were E h, dissolved oxygen, total dissolved solids, chlorophyll a, phosphate, Ba, Ca, Fe, Na, and Sn. The WQI proposed herein was effective in the classification of water quality for the periods analyzed.