The uncertainty of GIS-based interpolation methods in constructing shallow groundwater distribution map: A case study at Pleiku city, Gia Lai province

Four interpolation methods are applied to interpolate shallow groundwater level in Pleiku city, including inverse distance weighted, tension spline, universal kriging, and ordinary kriging. The cross-validation results record that the ordinary kriging is the best interpolation method which is shown by the lowest RMSE value, the highest R2 value.