Assessment of River Water Quality Using Weighted Arithmetic Water Quality Index in the River Kabini at Nanjangud, Karnataka, India

Abstract

Two sampling stations N1 and N4a are selected on the River Kabini stretch at Nanjangud, Karnataka, India. In this research, the assessment of the 20 year-data (2000 – 2019) indicate Water Quality Index of 75.3 and 95.3 at stations N1 and N4a respectively, which categorizes the water quality of the River Kabini at this stretch as “very poor”. This assessment is useful to policymakers in deciding future course of action to protect the river from anthropogenic deterioration. Also, statistical analysis in the form of t-test for the 17 – year, 3 – year and 20 – year period indicates the ‘p’ value (p = 0.29, 0.21 and 0.22) respectively, which is greater than the significant value 0.05. Similarly, the critical value during the 17 – year, 3 – year and 20 – year period is 2.06, 4.30 and 2.04 respectively and is also greater than measured t statistics values of -1.08, -1.79 and -1.26 respectively. This reveals that the difference in WQI of N1 and N4a monitoring stations is insignificant.