Groundwater classification and its suitability in Kadaladi, Ramanathapuram, India using GIS techniques

The hydrochemical characteristics of groundwater in Kadaladi Block of Ramanathapuram district, Tamilnadu have been evaluated based on different indices for drinking, industrial and irrigational purposes using “HYCH” program. Groundwater samples were collected in pre-monsoon and post-monsoon of 2012 from 36 locations and analyzed for major ions. The abundance of the major ions is in the order of Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and Cl⁻ > HCO₃ ⁻ > SO₄ ²⁻ > NO₃ ⁻ > PO₄ ³⁻. Interpretation of analytical data shows that most part of the study area is occupied with groundwater having higher TDS which is not suitable for drinking purpose. High to very high nature of hardness and corrosivity restricts groundwater use for the industrial purpose. SAR and RSC indicate that 70 % of the groundwater is suitable for irrigation in both the seasons. Spatial distribution map of USSL salinity classification shows that 70 % of the area comes under high to very high saline nature and medium to high sodium content makes the groundwater which is only suitable for high tolerant crops. Above statement is further supported by Schoeller and Stuyfzand classification, where most of the samples fall under the Type IV water and Brackish to Hyperhaline water. Gibbs and Langlier Saturation Index shows that 70 % of the groundwater sample chemistry is due to rock–water interaction followed by evaporation.