Water quality evaluation is the most direct and quantitative description of reservoir water environment. In view of the lack of biological factor evaluation in water quality evaluation at present, firstly the conventional pollution index evaluation system was used to evaluate the water quality continuously. Then the correlation between the evaluation indexes and the concentration of cyanobacteria was studied. After determining the correlation, a novel calculation method of cyanobacteria pollution index was determined by principal component analysis (PCA). The result showed that the eutrophication index and nitrogen phosphorus index of the water body were high. Biological pollution in reservoir cannot be ignored. The correlation between eutrophication index and cyanobacteria concentration only reached a weak correlation (Pearson correlation = 0.242). For the reservoir, it is necessary to establish a special cyanobacteria pollution index. Five variables participated cyanobacteria pollution index calculation by principal component analysis (PCA) method. The total variance of the two main components was 77.107%, which can reflect most of the data information. In the reservoirs of other areas, similar parameters can also be selected to calculate the cyanobacteria pollution index. This research provide reference for the biological factor evaluation of similar reservoirs in the world.
A special daily water quality test was used in order to make an accurate judgment on the water quality.
PCA was selected to establish the calculation method of the cyanobacteria pollution index by considering the relationship between cyanobacteria concentration and other water quality factors.
This research provide reference for similar areas of the world on water quality evaluation of reservoir.