Calculating and Comparing the Weighted and Unweighted Water Quality Indices for Cauvery River Banks based on Accuracy

Appraising the quality of water has been an important issue in recent decades. Common causes of Water pollution are affecting human activities and its consequences. Some of the sources that pollute the water bodies are Industrial Wastage, Global Warming, Fuel Spilling, Sewage Water etc. Water pollution affects dispersion of Biodiversity, contamination of Food Chain, Diseases, Infant Mortality etc,. Some of the solutions for water pollution are improved sanitation, sewage treatment and reuse for irrigation. Hence the accurate classification of water pollution is a very important activity to solve the water contamination. This paper demonstrated the accurate calculation of the Water Quality Indices (WQI) by using Weighted Mean and Unweighted Mean methods to predict the water quality. Water Quality Index is determined by evaluating arithmetic, Geometric mean for weighted index calculation and Harmonic Mean for Unweighted Index, The Sub-Indices (SI) of selected parameters for Weighted Arithmetic Mean Water Quality Index (WAMWQI) and Weighted Geometric Mean Water Quality Index (WGMWQI) are evaluated by proportional constant (K) with the standard values and ideal values of each parameters approved by World Health organization (WHO). The Sub-Indices (SI) of selected parameters for Unweighted Harmonic Mean Water Quality Index (UHMWQI) are evaluated by Oregon Unweighted Harmonic WQI (OWQI) method. Water samples are collected from the Tamil Nadu Pollution Control Board (TNPCB). WQI are calculated for the water samples for the different areas from the Cauvery River Basin of Tamil Nadu. The performances are compared by using the SPSS Tool by anova test and the results are represented as graphically by bar chart. The performance of WAMWQI is slightly higher than the other two methods. And also the WQI for the stations Thirumanimuthar and Sarabanga shows major differences between weighted mean method and unweighted mean method. But other stations do not show the major differences. Hence most of the stations which WQI are within the standard level got the same result from both the weighted and unweighted mean methods. After examining the parameters are selected according to the usage of water bodies. This kind of hopeful research helps the Tamil Nadu government agencies to take appropriate decisions among the levels of water pollution.