## 4 Results and Discussion
### Pollution Source Identification of Monitored Variables
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Parameters** & **F1 (a)** & **F2 (a)** & **F3 (a)** & **F1 (b)** & **F2 (b)** & **F3 (b)** \\ \hline Turbidity & 0.282 & \(-0.420\) & **0.452 \({}^{\text{c}}\)** & \(-0.032\) & \(\mathbf{-0.781\text{ }^{a}}\) & \(-0.320\) \({}^{\text{c}}\) \\ TDS & \(\mathbf{0.974\text{ }^{a}}\) & 0.136 & 0.044 & \(\mathbf{0.962\text{ }^{a}}\) & \(0.020\) & \(-0.084\) \\ EC & \(\mathbf{0.978\text{ }^{a}}\) & 0.078 & 0.079 & \(\mathbf{0.961\text{ }^{a}}\) & \(0.018\) & \(-0.098\) \\ PH & 0.285 & 0.324 \({}^{\text{c}}\) & \(\mathbf{-0.710\text{ }^{b}}\) & 0.056 & \(-0.178\) & \(\mathbf{0.775\text{ }^{a}}\) \\ NH\({}_{3}-\)N & 0.416 \({}^{\text{c}}\) & \(\mathbf{0.516\text{ }^{b}}\) & \(-0.313\) \({}^{\text{c}}\) & \(0.521\) \({}^{\text{b}}\) & \(-0.244\) & \(\mathbf{0.700\text{ }^{c}}\) \\ NO\({}_{2}-\)N & 0.428 \({}^{\text{c}}\) & \(-0.475\) \({}^{\text{c}}\) & \(\mathbf{-0.620\text{ }^{b}}\) & \(-0.088\) & \(\mathbf{-0.531\text{ }^{b}}\) & \(-0.064\) \\ NO\({}_{3}-\)N & 0.131 & 0.398 \({}^{\text{c}}\) & \(\mathbf{0.507\text{ }^{b}}\) & 0.195 & \(\mathbf{0.599\text{ }^{b}}\) & \(-0.168\) \\ PO\({}_{4}-\)P & \(\mathbf{0.871\text{ }^{a}}\) & \(-0.035\) & \(-0.174\) & \(\mathbf{0.830\text{ }^{a}}\) & \(-0.414\) \({}^{\text{c}}\) & \(-0.200\) \\ DO & \(\mathbf{-0.842\text{ }^{a}}\) & \(-0.055\) & \(-0.365\) \({}^{\text{c}}\) & \(\mathbf{-0.847\text{ }^{a}}\) & \(-0.246\) & \(0.186\) \\ BOD & \(\mathbf{0.784\text{ }^{a}}\) & \(-0.461\) \({}^{\text{c}}\) & \(-0.297\) & \(\mathbf{0.796\text{ }^{a}}\) & \(-0.394\) \({}^{\text{c}}\) & \(0.015\) \\ COD & \(\mathbf{0.793\text{ }^{a}}\) & \(-0.388\) \({}^{\text{c}}\) & \(-0.302\) \({}^{\text{c}}\) & \(\mathbf{0.721\text{ }^{b}}\) & \(-0.320\) \({}^{\text{c}}\) & \(0.135\) \\ TN & \(\mathbf{0.898\text{ }^{a}}\) & 0.064 & 0.101 & \(\mathbf{0.724\text{ }^{b}}\) & \(-0.015\) & \(0.047\) \\ TP & \(\mathbf{0.812\text{ }^{a}}\) & 0.139 & 0.436 \({}^{\text{c}}\) & \(\mathbf{0.897\text{ }^{a}}\) & \(-0.333\) \({}^{\text{c}}\) & \(-0.105\) \\ Temp & \(\mathbf{0.825\text{ }^{a}}\) & 0.290 & 0.194 & \(\mathbf{0.783\text{ }^{a}}\) & \(0.246\) & \(-0.143\) \\ Mg\({}^{2+}\) & 0.077 & \(\mathbf{-0.654\text{ }^{b}}\) & \(0.389\) \({}^{\text{c}}\) &  
'moderate', and 'weak', corresponding to absolute loading values of \(>\)0.75, 0.75-0.50, and 0.50-0.30, respectively. The first factor (F1), accounting for 46.8% of the total variance, showed strong positive loadings of TDS, EC, PO4 - P, BOD, COD, TP, TN, Na+, and temperature with factor loadings of 0.974, 0.978, 871, 0.811, 0.784, 0.793, 0.898, 0.812, 0.825, and 0.832, respectively; a weak positive loading of K+ (0.477); and strong negative loading of DO (\(-\)0.842) (Table 9). High positive loadings of temperature and high negative loading of DO might suggest the impact of seasonal variation, and temperature is inversely related to DO. The strong and moderate positive loading of BOD and COD signify biodegradation of organic matter and are negatively affected by DO of water bodies. F1 stands clearly for pollution by BOD or COD, and nutrients and oxygen depletion is a consequence. When the temperature of water bodies decreases, the biodegradation of organic matter decreases, and the solubility of oxygen in the water increases. Similar reports of high concentrations of BOD and COD exist elsewhere [42; 44; 45]. Similarly, the strong negative DO loading indicates the utilization of DO under anaerobic conditions in rivers and lakes for the degradation of organic matter. F1 showed strongly positive loadings for both COD and BOD, while the loading for DO was strongly negative. This indicates a group of purely organic pollution indicator parameters from industrial effluents, domestic discharges, and livestock affecting water bodies [23; 27; 51]. High nutrient loadings of factors such as TN and TP represent pollution from point and non-point sources from industrial setup, agriculture areas, domestic sewage, and urban runoff.