Assessment of groundwater quality for irrigation purpose in river basin, Dindigul, Tamil Nadu

Abstract

ABSTRACT The variation in intensity of rainfall and uncertainty in its distribution has forced us to inculcate the tapping of groundwater for agricultural purposes to such reasons, it has become critically important to analyse the quality of groundwater to determine its suitability for agricultural purpose. The current study has been carried out to demarcate the groundwater suitable zones using GIS for its usage for good agricultural practices. A total of 60 groundwater samples are collected and analysed for various parameters such as electrical conductivity (EC), pH, total dissolved solids, major cations and anions. The suitable zones for irrigation purpose and action plan for sustainable practices are suggested by computing the various irrigation water quality indices, namely, sodium adsorption ratio (SAR), sodium percentage (Na%), residual sodium carbonate (RSC), magnesium hazard ratio (MHR), Kelly’s ratio (KR) and permeability index (PI). The integrated method of suitability evaluation revealed that groundwater is excellent for irrigation in 2.65 km2 area of basin. It is good for irrigation in 496.88 km2 area of basin. It is permissible in an area of 677.72 km2, doubtful in an area of 438.84 km2 and unsuitable in 322.96 km2 of area. The study suggested that the advanced method of treatment such as reverse osmosis and membrane filtration is needed to treat the groundwater for irrigation and sustainable practices.