Estimation of the correlation between oxidizability and water flow rate while passing through the water storage reservoir dam

Summary

The results of studying temporal variability of water oxidizability in the Ufa River are presented. The work was in determining the frequency distribution of the studied values, probability of unfavorable conditions related to the deterioration of the water quality in relation to the studied parameters, and searching for the correlation between the indicators and water flow rate. The oxidizability in the Ufa River during flood periods is formed to a lesser degree by organic substances washout from the catchment basin and to a greater extent is determined by the water quality in the water storage reservoir and organic substances in the bottom deposits. The frequency distribution of this indicator has been determined; the probability of unfavorable conditions occurrence (floods and high water) accompanied by the deterioration of the water quality in relation to the oxidizability has been estimated. It was determined that the oxidizability probability distributions had a tail part shifted in the direction of larger values of the indicator and showed that during unfavorable periods the oxidizability exceeded 5 mg/dm³. The frequency distribution of the tail part of the indicator approximated by power law P₁(О) =
= 337681·О^–6,96 (R² = 0,92). It was stated that upon the occurrence of unfavorable conditions (floods and high water) the oxidizability of water in the river would not exceed the preset value (11 mg/l) with probability 97%. It was shown that during flood periods the water flow in the river higher than 450 m3/s enhanced the increase of the oxidizability values. The correlation between oxidizability increase and water flow passing through the dam was determined and expressed in the form of equation. The average prediction error was 16%.

Key words

reservoir , water flow , oxidizability , frequency distribution , distribution probability , inverted distribution