Characteristics of water quality and pollution source apportionment in wet season and dry season based on absolute principal component score-multiple linear regression in Guangdong section of Jiuzhou River
To explore the characteristics of water quality and identify the pollution sources in Guangdong section of Jiuzhou River during wet season and dry seasons,the daily monitoring data of Yingzai national examination section of Jiuzhou River were chosen.The characteristics of water quality and pollution sources in wet and dry seasons were analyzed by using correlation analysis and absolute principal components-multiple linear regression model(APCS-MLR).The results showed that the values of permanganate index,total phosphorus,and turbidity in wet season were higher than those in dry season.However,the values of dissolved oxygen and pH in wet season were lower than those in dry season.Compared to the dry season,the correlations between pH,dissolved oxygen,turbidity,and other water quality indexes increased in wet season while the correlations between permanganate index,ammonia nitrogen,total phosphorus,and total nitrogen in wet season decreased significantly than those in dry season.During the dry season,the livestock and poultry breeding sources and urban living sources contributed 58.47%,48.71%,and 44.14%,of total phosphorus,ammonia nitrogen,and total nitrogen,respectively.In the dry season,the absolute contribution rate of unidentified pollution sources to permanganate index,water temperature,pH,and conductivity were 63.08%,59.48%,54.90%,and 52.65%,respectively.During the wet season,the absolute contribution rate of agricultural non-point sources to total nitrogen,total phosphorus,and permanganate index were 51.96%,41.38%,and 34.78%,respectively.The absolute contribution rates of meteorological factors to dissolved oxygen,pH,and ammonia nitrogen in wet season were 55.66%,40.75%,and 31.87%,respectively.In conclusion,the water quality indexes of Jiuzhou River were greatly affected by livestock and poultry breeding sources and unidentified pollution sources in dry season.In the wet season the main pollution sources of Jiuzhou River were agricultural non-point sources,urban non-point sources,and meteorological factors.To improve the water quality of Guangdong section of Jiuzhou River,the following tasks must be completed:control of livestock and poultry breeding pollution,improvement of the urban sewage network,scientific protection of ecological flow,and reduction of non-point source pollution during flood season.
APCS-MLRsource apportionmentwet and dry seasonJiuzhou River