Statistical aspects of dayly fluctuations of water quality indicators (on the example of the Kama reservoir)

Abstract

Water bodies located in zones of active technogenesis are characterized by significant time variability of hydrochemical indicators of water quality. When conducting traditional monitoring of water bodies with water sampling using standard bathometers, the values of monitored water quality indicators are determined, as a rule, with a characteristic time averaging of ~10 seconds. The problem arises, however, as to how do these indicators relate to their average daily values? What should be the minimum averaging period in order to obtain objective average daily values of the considered water quality indicators? The paper considers the application of the analysis of variance to study every-second and five-minute observations of water conductivity and turbidity for two sections
of the Kama Reservoir: the Chusovskoy Ples area of Perm and the Berezniki area. It has been demonstrated that water quality monitoring in the Perm area of the Kama Reservoir should be based on the evaluation of integral sampling methods with a time averaging scale of at least 10 minutes. At the same time, with regard to the Kama reservoir near Berezniki, the need for integrated sampling with averaging of at least 1.5 minutes is confirmed