Abstract:
Water quality indices are mathematical equations
that transform water quality data into a particular
number which describe the status of water. A number of
water quality indices have been developed by various
researchers for categorizing the water quality for different
uses. These indices are developed based on classification
criteria, sub-indices, and aggregation function. In
the present study, a generalized Composite Water Quality
Index (CWQI) is developed to classify the water into
five categories, viz excellent, good, fair, poor, and polluted.
For this purpose, the concentration ranges have
been categorized on the basis of the Indian Standards
(IS) and Central Pollution Control Board (CPCB) standards
and considering International standards of World
Health Organization (WHO) and European Commission
(EC). Twenty-five water quality parameters are
selected based on the social and environmental impacts,
and weights are computed using the Saaty’s Analytic
Hierarchy Process (AHP) Multiple Criteria Decision
Analysis (MCDA) tool. These parameters are selected
such that the same indices can be used to assess the
quality of both surface and ground water. The computed
weights minimize the subjectivity in assigning the parameter
weights. The proposed index improves understanding
of water quality issues by integrating complex
data and generates a score which describes the status of water quality. The index will be very useful for the water
management authorities to maintain good health of surface
water resources.
