Application of SVR-kernel models for nitrate contamination vulnerability assessment in the shallow aquifer of Miryang City, Korea

The assessment of groundwater contamination vulnerability is crucial for the effective management and conservation of groundwater. The purpose of this study is to determine the most accurate SVR-kernel model among four kinds of SVR-kernel models for the assessment of groundwater contamination vulnerability to nitrate in Miryang City of Korea (South) which has two functions of urban and rural activities. Some statistical data of MAE, RMSE and ρ, ROC/AUC, graphical comparisons between target nitrate values and predicted nitrate values for training and testing data, and spatial maps of predicted nitrates were used for the evaluation of four kinds of SVR-kernel models. SVR-Polynomial model made the least MAE (0.045) and RMSE (0.063), and largest correlation coefficient (0.887) and ROC/AUC (0.83) for the test data. Graphical comparisons and spatial maps also represented the superiority of SVR-Polynomial model. DRASTIC thematic maps and predicted nitrate maps indicated the high groundwater contamination vulnerability around Nakdong River and Miryang Stream. Thus, the effective countermeasure is required for the management and conservation of groundwater in Miryang City of Korea (South). This study can contribute to the decision-making of the countermeasure.