41-Carbonate and Bicarbonate Chemistry for Assessing Hydrogeological Dynamics in a Sub-Basin of Kabini river Basin in Karnataka

Abstract

The quality of groundwater in a watershed depends on several factors (i) specific characteristics of the watershed (e.g., climate, hydrological pathways, vegetation, and size of the watershed), and (ii) factors directly related to the chemical species and mechanisms that control their release (e.g., differential breakdown of rock and/or soil minerals) and their transport into solution (e.g., organic and inorganic complexation and sorption onto mineral surfaces). Analysis of ground water flow regime is complex in watersheds due to several factors such as: presence of long lineaments, excessive pumping and limited hydrogeological data. Chemical signature of ground water can be of great help in delineating factors and using them in the modeling of groundwater dynamics. This study uses analysis of groundwater chemistry for understanding the hydrogeology of Gundal sub-basin in the Kabini river basin. The equilibrium concentration of carbonate and bicarbonate vis-a-vis the concentration of other ions has been analyzed. These chemical signatures are used to infer the high draft zones and subsurface inflows into the region.