Analysis of groundwater quality for irrigation purpose in Pennagaram block of Dharmapuri District, Tamilnadu, India

Groundwater is an indispensable source of water due to its substantial use for domestic, irrigation, and industrial purpose. This study is determined to examine the irrigation quality of groundwater in the seasons of pre-monsoon (PRM) and post-monsoon (POM) in the year 2013 at Pennagaram block of Dharmapuri district, Tamilnadu. A few samples of groundwater from the study area are analyzed for their physicochemical parameters (APHA, 1998). The parameters to examine irrigation quality of the samples taken in this study are Cl-/HCO3- ratio, percent sodium (%Na), Index of Base Exchange (IBE), Residual Sodium Carbonate (RSC), Kelly's ratio (KR), Permeability Index (PI), Sodium Adsorption Ratio (SAR), Potential Salinity (PS), Magnesium Ratio (MR), Salinity Index and Sodicity Index. The classification of groundwater samples for irrigation was identified using the USSL Diagram, Doneen's plot, and Wilcox diagram. The spatial distribution map gives a clear depiction of the groundwater quality for irrigation purposes, in both seasons. The plot of Cl-/HCO3- versus Cl- indicates that the groundwater samples are strongly affected by salinity. It illustrates the exchangeable mechanism which has one of the responses for the chemical composition of groundwater in the study area. According to %Na, RSC, KR, SAR, PI, MR, Salinity index, and Sodicity index makes the groundwater of the study area was safe for irrigation. According to the results of PS and Sodicity index the groundwater of marginal quality i.e., closely unfit for irrigational purpose. (C) 2019 Elsevier Ltd. All rights reserved.