This study aims to assess the mechanism controlling hydrochemical characteristics and water quality of the surface water source of the Thuthapuzha River Basin (TRB), one among the major tributaries of Bharathapuzha River– the largest west-flowing river in Kerala, India, and its suitability for drinking. Surface water samples (15) collected during the premonsoon from the Thuthapuzha River were analysed for 18 parameters. The water samples from Thuthapuzha are slightly alkaline. Almost all the parameters studied were within the prescribed limits set by WHO, BIS, and ICMR. Hence, qualitatively, the water is suitable for drinking. When plotted on a Piper diagram, most water samples are of the Ca-HCO3 type. From the Gibbs diagram, the majority of samples fall in the facies field between the atmospheric precipitation and rock dominance. The weathering plots indicate the dominance of silicate weathering in the study area, which contributes a substantial part of the chemical load. The correlation matrix also shows that the majority of the parameters exhibit a positive correlation (EC, TDS, Ca, Mg, Na, Cl, and HCO3). Principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicates that river water chemistry is primarily controlled by silicate weathering and secondarily reflects redox-sensitive geochemical processes and anthropogenic nutrient inputs. The Particulate Load (PL) and Dissolved Load (DL) ratio has been calculated for the drainage channel at the gauging station to be 1.31, indicating the dominance of physical weathering in these high-gradient, humid terrains. The high gradient terrain characteristics of the river basins, which offer only very short residence time for the stream waters to interact with the bed rocks and subsequent release of ions to sediment (suspended and dissolved) transport.
Sherin et al. (Sun,) studied this question.