Evaluation of groundwater quality of Mersin province Anamur and Aydincik districts in terms of irrigation

The quality of irrigation water as well as the amount, significantly affects plant yield. Especially in coastal areas, groundwater may be subject to seawater intrusion. Spatial and temporal changes in the quality of all groundwaters, especially in coastal areas, should be constantly monitored. In this study, samples were collected from 51 groundwater wells in Mersin province, Anamur district, in August 2021 to determine the quality of groundwater used for irrigation, especially in greenhouses. To determine the hydrochemical properties of groundwater, the values of pH, EC, Na, Mg, K, CI, SO4, HCO3, Ca were determined. To investigate the usability of groundwater for irrigation, the values of percent sodium (%Na), PI, RSC, PS, MR, KI, SAR were calculated. Spatial distribution maps of hydrochemical properties and indices of irrigation water quality were prepared using geographic information systems, and correlation analyses were performed to study the relationships among quality parameters. As a result of the study, it was found that EC values of groundwater in the area vary between 0.475 dS/m and 1.13 dS/m, and 92.03% of the area belongs to class 3 in terms of irrigation. The Mg values vary from 7.293 mg/l to 99.54 mg/l, and it was found that the water in 9.71% of the area is not suitable for irrigation in terms of Mg content. The values of potential salinity (PS) vary from 1.375 to 7.295 and 84.91% of the area is in the medium class in terms of irrigation. The K values of groundwater varied from 0.391 mg/l to 10.557 mg/l and it was found that groundwater in 68.3% of the area is not suitable for irrigation. Groundwater quality in the area was not considered high enough to cause major irrigation problems. However, since it is a coastal region, it is proposed that the groundwater in these regions be used in a controlled manner.