Abstract
Mountainous catchments are one of the world’s important water sources that sustains a major portion of global population and a rich biodiversity. The groundwater quantity and quality of mountainous watersheds are depended generally on the geologic characteristics and climate gradients. Although many groundwater studies have been carried out in the midlands and lowlands of many river basins, not enough focus has been paid to the mountainous catchments of tropics. Here we report a case study on groundwater quality and controlling factors of a mountainous catchments of the Western Ghats mountain ranges of peninsular India - the Bhavani river basin, which is identified as a testbed for long-term monitoring of the Critical Zone process. A total of 88 water samples were collected seasonally for assessing various physico-chemical parameters, solute contents and scaling properties. The results of the study revealed that the hydrochemistry of groundwater is influenced by both silicate and carbonate weathering. Mineral stability indices computed for the groundwater reveal that about 52 % of the samples are supersaturated with carbonate minerals and often exhibit scaling due to solute overloading. Among the contributing factors that determine water quality of groundwaters, chemical weathering and anthropogenic activities play a significant role.