Discriminant Analysis Method Application in Water Quality Assessment: Take Yinma River as Example

Discriminant analysis method was used to differentiate and classify the water quality of 4 cross sections in Yinma River basin. After the introduction and elimination of variables, dissolved oxygen, nitrate, total phosphate, chemical oxygen demand, potassium permanganate index and chloride are selected to be the 6 main assessment factors in turn. Numeric model for assessment of the surface water quality is established, and its discriminant analysis function can be successfully used to differentiate the surface water quality. It is showed that the water quality of Yinma River and Chalu River is relatively good, most of which belongs to water quality II, and little belongs to water quality I; the water quality of Shuangyang River is relatively poor, reaching water quality V, and little belongs to water quality IV. It is shown by study that the application of Discriminant Analysis method in water quality assessment has certain actual significance, and the selected variables have significant function for differentiating water quality.