Abstract
This research evaluated the groundwater quality of Thiruthuraipoondi city in the southern part of Tamil Nadu, India during summer and monsoon seasons in 2011. Eighteen groundwater samples were collected throughout Thiruthuraipoondi city and its surroundings. This case study represented that the combined analysis of ordinary kriging and CCME WQI in GIS was effective to evaluate the groundwater pollution sources, as well as for the spatial interpolation and assessment of groundwater quality. Groundwater samples evaluated by CCME WQI values belonged to good quality sectors in summer and monsoon, but to poor quality sectors at small patches of south and southeast directions in both seasons. Moreover, the higher concentration of Na and Cl was designated as irrigation waste and also seawater incursion. Based on the Piper plot, most of groundwater samples belong to Ca–Mg–Cl2 type and followed by Ca–Cl2 and Na–Cl types in summer season. In case of monsoon season, most of the groundwater samples dropped in Na–Cl type and followed by Ca–Mg–Cl2 and Ca–Cl2 water types. In Wilcox diagram, most of groundwater samples in both seasons occupied S2 and C4 categories of medium sodium hazard and very high salinity hazard, respectively. This research represented that higher concentration Na and Cl resulted from anthropogenic activities and seawater incursion due to overpumping of groundwater. An effective groundwater management plan of artificial recharge is necessary to conserve valuable groundwater resources in Thiruthuraipoondi city.
Acknowledgments
This research was supported by a grant (code 14AWMP-B066761-02) from AWMP Program funded by Ministry of Land, Infrastructure and Transport of Korean government, and Department of Science and Technology (Project No: DST/WAR-W/WSI/02/2010), New Delhi, India.