International Journal of Environmental Sciences

Volume 2 Issue 4 2012           Pages:2155- 2166

Silicate or Calcite weathering in Wet-Dry climate in Lower Varahanadi Basin, Tamilnadu, India – A determinant in global warming

Author Information:

Ramesh K Centre for Water Resources, Anna University, Chennai

Gowri V. S Institute for Ocean Management, Anna University, Chennai

ABSTRACT

Only about 15% of the water samples are fresh and the remaining is brackish water in the lower Varahanadi Basin, Tamilnadu, India. Four hydrochemical facies of groundwater (Ca2+HCO3- type; Na+Cl- type; Mixed Ca2+Mg2+Cl- type and Mixed Ca2+Na+HCO3- type) are identified. Abundance of cations and anions occurs as Na>Ca>Mg>K and HCO3>Cl>SO4>CO3>NO3. The positive and negative chloro-alkaline indices indicate ion exchange reactions depending on the season, mixing of water and evaporation process. The plots of Na+/Cl- ; Na+/Cl- vs EC and Ca2+ Mg2+ Vs SO42+HCO3- suggest predominance of silicate weathering in this wet-dry basin. Cationic ratio indicates higher silicate and lesser calcite weathering. Thus continental silicate weathering which can consume more of carbonic acid could play a role in environmental consequences such as global warming.

Keywords: Electrical conductivity, Evaporation dominance, Hardness, Silicate weathering

DOI: 10.6088/ijes.00202030098


© 2012 Copyright Ramesh K and Gowri V. S, licensee IPA.This is an open access article distributed under the Creative Commons Attribution License (2.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The electronic version of the article can be downloaded below.

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