| According to the data from 2012 to 2013, with 42 monitoring section at five regions around Danjiangkou reservoir area, principal component analysis method was applied to identify the main pollution factor which influenced surface water quality and calculate the weight so as to make a comprehensive evaluation of water quality in different river basin. The first principal components are total nitrogen, dissolved oxygen, biochemical oxygen demand, total phosphorus, ammonia nitrogen,and potassium permanganate index; the second principal componentsare fluoride, fecal coliform; the third principal component is chemical oxygen demand (COD). The weight coefficient of the water index was 5.022, 2.256, 1.508. Comprehensive evaluation results showed that, the city of Shiyan and Danjiangkou in Hubei were polluted relatively seriously, followed by the city of Nanyang in Henan province, Shangluo city in Shanxi province, Ankang city and Hanzhong city in Shanxi province. |
