TEMPORAL AND SEASONAL CHANGES IN GROUNDWATER QUALITY IN AN AGRICULTURE DOMINATED AREA

Utilization of groundwater has increased manifold due to advancement in agrarian sector. The water quality of alluvial aquifers is highly sensitive to the use of agricultural chemicals (e.g. fertilizers, pesticides, and lime) and geologic conditions. Uncontrolled extraction without commensurate recharge and heavy leaching of pollutants from pesticides and fertilizers may result in pollution of groundwater. Monitoring the quality of groundwater, particularly in agriculture intensive areas is as important as assessing its quantity. Kaithal District of Haryana state is agriculture dominated area which is largely dependent on groundwater. The present study was carried out in the district to analyse temporal changes in groundwater quality and to evaluate the effect of monsoon on different parameters that determine suitability of groundwater for irrigation and to assess overall suitability combining all these parameters. Survey of India toposheets, pre- and post-monsoon chemical analysis data of 79 observation wells along with monthly rainfall data for the period under study was used in the analysis. The spatial distribution maps for EC, SAR, SP and RSC were prepared in GIS environment using ILWIS 3.6. The study area was classified into different zones of suitability for irrigation as per international standards. From the analysis of EC values from 2001 to 2007, it was revealed that there was significant increase in average EC in all the blocks of the district, indicating a regular deterioration in quality. The cross map obtained from spatial distribution maps of EC, SAR, SP and RSC for 2007 showed that groundwater quality was found to be good to moderate in Gulha, Pundri, and Kaithal blocks, whereas doubtful to non-suitable in Rajaund and Kalayat blocks. Percent sodium was particularly found higher than permissible limits throughout the district. Further, a moderation in water quality was observed after the monsoon season, which can be attributed to a possible dilution due to groundwater recharge.