Seasonal characteristics of chlorophyll-a and its relationship with environmental factors in Yunmeng Lake of China.

Sampling was carried out according to the season, in order to analyze the seasonal characteristics of chlorophyll-a and its relationship with environmental factors in Yunmeng Lake on 1st May, 12th August, 1st October and 14th December of 2013. The results showed that the average annual water temperature, pH, TP, TN and chlorophyll-a concentration in Yunmeng Lake was 15.9°C, 7.12, 0.07 mg l(-1), 1.58 mg l(-1) C and 30.60 μg 1(1) respectively. The water quality was Class IV water or eutrophic type. Water chlorophyll-a was significantly positive with pH and TP(R(2)=0.6077 p<0.01; R(2)=0.5855 p<0.01), low correlation with water temperature (R(2)=0.0566 p>0.05). lg (Y(Chl a)was significantly positive with lg(X(TP))(R(2)=0.5176 p<0.01), N/P was 22 and P may be restricted.