Sources, spatio-temporal distribution and depth variations in groundwater salinity of the semi-arid Rohtak district, Haryana, India

Groundwater salinity was evaluated in the Rohtak district of the state of Haryana in northwestern India. The groundwater samples were collected from 82 villages of the district. Both post-monsoon and pre-monsoon samplings were carried out for two consecutive years (2017-2019). A total of 620 samples in the four seasons (155 in each season) were collected under strict QAs and QCs from APHA. The co-existing hydro-chemical parameters of salinity, total dissolved solids (TDS) and electrical conductivity (EC) were determined. ArcGIS 10.5 was used for spatiotemporal distribution evaluation. Groundwater salinity values between 0.20 and 8.00 parts per thousand (ppt) were obtained. Hand pump water is more saline (0.3-7.5 ppt) than bore-well (0.2-1.8 ppt) and dug-well water (0.6-1.3 ppt), thus limiting the options for viable water sources. Higher groundwater salinity in the post-monsoon season as compared to pre-monsoon season was observed. Groundwater salinity in the Rohtak district decreases in the order: Lakhan-Majra < Meham < Rohtak < Sampla < Kalanaur. Safer groundwater salinity levels were found in deep bore wells (>20 m) versus shallow bore wells (<20 m). Thus, this study evaluates the spatio-temporal and depth variations in groundwater salinity of Rohtak district. Possible remedial measures for salinity problems are proposed.