Irrigational Feasibility of Groundwater and Evaluation of Hydrochemistry Facies in the SIPCOT Industrial Area, South Tamilnadu, India: A GIS Approach

Abstract

Tuticorin coastal city, Tamilnadu, India, has been selected to discuss the impact of pre-monsoon and post-monsoon on groundwater quality for irrigation in the region where agriculture is the main livelihood of the people and groundwater the main source of irrigation in the area. A total of 72 groundwater samples were collected and 13 water quality parameters were analyzed using standard procedures. It is observed that the major cations, Sodium played a dominant role in pre-monsoon (PRM) but in the post-monsoon (POM) period potassium was dominant. Among the major anions, sulphate played a dominant role in PRM, but in the POM period Chloride and Bicarbonate was dominant. The concentrations of the major ions are found to be high in the case of POM indicating leaching and anthropogenic activities predominates over dilution of the groundwater. From the Hill-piper plot was observed that the alkalies exceed the alkaline earths and strong acids exceed weak acids. In the case of anions, during the two periods strong acid shows dominance over weak acids during the both seasons. For assessing the groundwater for irrigation suitability parameters like total hardness, residual sodium carbonate, permeability index, sodium percentage, kelleys ratio, magnesium hazard and sodium adsorption ratio suggest that the groundwater of the study area is moderately suitable for irrigation purposes. Higher sodium adsorption ratio and magnesium hazard were noticed during POM indicating the effect of leaching and dissolution of salts into the aquifer matrix.