Assessment of water quality of the Narmada River (India) using the fuzzy water quality index method

ABSTRACT This study aims to assess the water quality of the Narmada River utilizing the fuzzy water quality index (FWQI) method. In this context, samples of water were gathered from six stations for various parameters such as turbidity, pH, DO, BOD5, TDS, TSS, COD, EC, TH, TA, and chloride from 2017 to 2022. Due to contamination from urbanization, water quality assessment has become essential. To address this requirement, the water quality index (WQI) was developed which incorporates various water quality parameters and expresses total water quality into a single value. Nowadays, a new method, the FWQI has been developed. To develop FWQI, 11 inputs, single output, Mamdani method, And operators, fuzzy inference rules, and centroid methods for defuzzification have been used. The average values of FWQI at the first, second, third, fourth, fifth, and sixth stations were 61.28, 57.66, 62.18, 61.90, 50.00, and 49.96, respectively. Meanwhile, the average values of WQI for the same stations were 57.98, 57.40, 58.97, 58.85, 48.39, and 49.03. The findings from both methods revealed that water quality was poor at the first four stations and good at the last two stations. This new index could serve as an alternative approach to assessing water quality.