3.1 Water Quality Index determination
In this study the water quality index (WQI) was determined according to Bhargava method.
The Bhargava method was adopted because of its simplicity involved in handling small to
large data for various beneficial uses. The simplified model for WQI for a beneficial use is
given by equation
WQI n
i=1 = [π fi (pi)] 1/n x 100 1
Where n is the number of variables is considered more relevant to the use and (f i) P i is the
sensitivity function of the i th variable which includes the effect of weighting of the
i th variable in the use.