SPACE-TIME VARIABILITY OF WATER QUALITY PARAMETERS THROUGHOUT THE MONITORED SEGMENT OF THE RIVER IGUAÇU

Abstract

NBRs n. 9.897 (ABNT, 1987a) and n. 9.898 (ABNT, 1987b) are a help in the monitoring of hydric resources since they suggest the site and number of sample sites, including those throughout the transversal section of the river which vary according to breadth and depth. In the wake of the complexity and resources required for the monitoring of rivers, usually such sampling is discarded and replaced by the river´s margin. So that the sampling site´s influence may be verified, the variations of the concentrations of water quality parameters throughout the river´s transversal section are evaluated at different hydrological conditions. Five sampling sites distributed along the studied segment were monitored. There was a great dispersion throughout the river´s segment with regard to organic parameters and there was a specific trend in gradual distribution of concentration for each BOD and COD parameter. The analysis of variance showed that there was no significant difference between sampling sites. There were no negative impacts with regard to the management of hydric resources caused by information on water quality samples at the river´s margin. In current study case, the number of sites suggested by the above norm may be simplified to a single site within monitoring.