Abstract
The extremes effects in parameters readings which are BOD (Biological Oxygen Demands) and DO(Dissolved Oxygen) can caused error estimating of the model’s parameters which used to determine the ratio of de oxygenation and re oxygenation of the dissolved oxygen(DO),then that will caused launch big amounts of the sewage pollution water to the rivers and it’s turn is effect in negative form on the ecosystem life and the different types of the water wealth.
As result of what mention before this research came to employees Streeter-Phleps model parameters estimation which are (Kd,Kr) the de oxygenation and re oxygenation ratios on respectively, after detect and putting aside the extremes effects by follow some suggested algorithms.
The experimental results shows the effects of parameter estimators and the mean square errors(MSE) that belong to it by the different ratio of extremes.
We can follow some other estimating methods such as (bias and robust estimators ) to remove the effect of the extreme values specially with the ratio more than (20%).
