## 3 Results and Discussion  
### Groundwater Hydrochemistry Assessment  
Thirteen water quality measures were statistically examined in order to have a better knowledge of the fundamental chemical properties of groundwater for both pre-irrigation and post-irrigation periods. The results are displayed in Table 1. The drinking water quality limitations for these water quality measures are also listed in Table 1[6]. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multirow{2}{*}{**Units**} & \multirow{2}{*}{**WHO**} & \multicolumn{6}{c}{**Pre-Irrigation**} & \multicolumn{6}{c}{**Post-Irrigation**} \\ \cline{3-14}  & & & **Min** & **Max** & **Mean** & **SD** & **CV (\%)** & **Min** & **Max** & **Mean** & **SD** & **CV (\%)** \\ \hline pH & - & 8.5 & 7.00 & 7.70 & 7.40 & 0.19 & 2.58 & 6.71 & 7.79 & 7.34 & 0.25 & 3.37 \\ EC & \(\mu\)S/cm & 1500 & 484.00 & 3090.00 & 977.40 & 601.47 & 61.54 & 483.00 & 3833.63 & 1105.13 & 756.66 & 68.47 \\ TDS & mg/L & 1000 & 314.60 & 2008.50 & 635.31 & 390.95 & 61.54 & 313.95 & 2491.86 & 718.33 & 491.83 & 68.47 \\ Na\({}^{*}\) & mg/L & 200 & 15.89 & 295.41 & 65.60 & 64.66 & 98.56 & 12.58 & 230.89 & 54.71 & 50.44 & 92.18 \\ NH\({}_{4}\)\({}^{*}\) & mg/L & 1.5 & 0.01 & 0.05 & 0.03 & 0.01 & 42.55 & 0.00 & 0.04 & 0.02 & 0.01 & 56.43 \\ K\({}^{*}\) & mg/L & 20 & 0.66 & 189.35 & 15.87 & 47.11 & 262.84 & 0.53 & 161.21 & 15.25 & 35.80 & 234.86 \\ Mg\({}^{2*}\) & mg/L & 50 & 12.22 & 115.43 & 35.76 & 24.96 & 69.80 & 13.20 & 105.09 & 31.67 & 21.70 & 68.54 \\ Ca\({}^{2*}\) & mg/L & 100 & 57.40 & 408.60 & 123.59 & 79.68 & 64.47 & 52.56 & 502.31 & 124.14 & 96.90 & 78.0 One of the most crucial factors determining the quality of drinking water is pH. Water corrosion is caused by low pH levels, while high pH levels negatively impact human skin and eye health as well as water taste [29; 30]. The research region's values of pH ranged from 7.00 to 7.70 and 6.71 to 7.79, with averages of 7.40 and 7.34 during the pre-irrigation and post-irrigation periods, respectively. These results suggest that the water quality in the area is alkaline. It was observed that the pH values measured in both periods were close to each other. The pH range that the WHO recommends (6.5-8.5) is still met by all of the samples. The amount of dissolved particles in the water directly affects the electrical conductivity (EC) of the water [31]. The EC concentrations of the samples varied between 484 and 3090 \(\upmu\)S/cm during the pre-irrigation period, possessing an average of 977.40 \(\upmu\)S/cm, and between 483 and 3833.63 \(\upmu\)S/cm during the post-irrigation period, with a mean of 1105.13 \(\upmu\)S/cm (Table 1). Total dissolved solids (TDS) are a unit of measurement used to describe the total quantity of salt solubilized in water. While very high TDS can also be caused by chemical fertilizers, residential wastewater, and irrigation return flows, it generally denotes the extent of rock-water interactions [32; 33]. In both irrigation periods, TDS values vary from 314.60 to 2008.50 and 313.95 to 2491.86 mg/L, with means of 635.31 and 718.3 mg/L, respectively. The current study presents the regional distributions of analytical cations and anions during both periods, as illustrated in Figures 3 and 4. Figure 3: _Cont._  
Figure 3: Spatial distributions of analytical cations and anions for pre-irrigation period in the study area. Figure 4: \(Cont.\)  
The hierarchy of cation prevalence in groundwater on Harran Plain is Ca\({}^{2+}\) > Na\({}^{+}\) > Mg\({}^{2+}\) > K\({}^{+}\), based on their average concentrations for both periods. One of the most prevalent cation ions in the groundwater of the area under study is sodium. In general, fertilizer use and the weathering of minerals like feldspar are the most frequent sources of Na\({}^{+}\) in the research area [34; 35].