Magnesium hazards (MH)
High magnesium concentration leads to an adverse effect on the soil structure and reduces the crop yield (Kuvurmaci and Karakus 2020). In the study area, MH ranges from 8.08 to 79.20%, with an average of 48.75%. The value of MH is less than 50%, thus being suitable for irrigation. About 46.67% of samples are found to be suitable, and 53.33% of samples are found to be unsuitable for irrigation uses. In the spatial analysis, 351.49 sq.km area falls under the suitable and 315.46 sq.km areas fall under the unsuitable of groundwater for agriculture purposes (Fig.11d). Excessive concentration of magnesium is due to the process of exchangeable sodium ions in groundwater. A weathering of parent rock, dissolution of calcite, and dolomite are the factors that influence the concentration of magnesium ions.