Water quality index (WQI), multivariate statistical and GIS for assessment of surface water quality of Karamana river estuary, west coast of India

Abstract

The present study intends to evaluate and characterize the river water quality of the Karamana river estuary, one of the significant rivers on India's west coast, utilizing a combination of the Water quality index (WQI), multivariate statistical, and GIS approaches. The river's source is at Agastyar Koodam on the southernmost extremity of the Western Ghats, and it serves as a significant source of water for Trivandrum's residents' domestic and drinking water needs before mixing with the Arabian Sea on India's west coast. Analyzing water quality is one of the most crucial components of surface water investigations. The level of pollution is significantly influenced by the water quality. By analysing water samples, an attempt is made to comprehend the water quality of the Karamana River Basin, and suggestions are offered for the prudent use and managing of water resources. Twenty water samples were taken from various sampling locations in order to evaluate the water quality. The estuarine water environment is controlled by the physico-chemical parameters, main ions, and trace elements of the water quality attributes. The quality of the water was assessed using the following parameters: pH, TDS, Ca, Mg, Na, K, Cl, SO4, HCO3, CO_3, NO₃, and Trace elements (Fe, Cu, Cr, Ni, CO, Cd and Zn). The majority of the samples were classified as having fair to good water quality, as determined by the WHO-permitted standards used to construct the water quality index (WQI). The quality of water is seen to be fair to marginal in the midstream to downstream zone, where anthropogenic activities are predominant.