Analysis of Water Quality of Selected Irrigation Water Sources in Gandevi Taluka of Navsari District of South Gujarat, India

Groundwater quality was evaluated for irrigation purpose by collecting the groundwater samples from 20 different locations during pre-monsoon and post-monsoon seasons. These groundwater samples were analyzed for physico-chemical parameters like pH, EC, TDS, major cations, and anions. Furthermore, irrigation quality indices like salinity hazard, chloride hazard, magnesium hazard, carbonate and bicarbonate hazard and sodium hazard were calculated using the analytical results. The average SAR, Na+ ion, PI, MH and IWQI varied from 6.34 to 2.53, 14.13 to 5.44 me/l, 68.31 to 56.76 me/l, 73.16 to 76.72 %, and 44.24 to 31.25 me/l, during pre-monsoon and post-monsoon seasons respectively. Based on the EC, more than 50% of the samples are falling under high salinity category in both seasons. Overall in Gandevi taluka, based on IWQI, 40 % and 45 % surveyed water samples were found falling in severe restriction category of irrigation during before and after monsoon respectively. The study revealed that most of the water samples are exceeding the critical levels of irrigation water quality and it may require careful management to grow suitable crops in the study area. In addition, the study also points out that usage of such a high TDS groundwater for irrigation may cause soil salinity.