Abstract:

Three methods were applied to water quality assessment for Zhangwu reservoir, including the single factor water quality identification index, comprehensive pollution index and organic pollution index methods, so as to know its environmental quality status. The assessment was based on water quality data from 2009 to 2015 and water quality requirements. The results suggested that (1) TN was the main pollution factor in the reservoir, it could meet the requirement of water quality for only four months, and its annual single factor water quality identification index was greater than six; TP was the second factor exceeding the standard of water quality in 53 months, and its annual average index could not meet the requirement except in 2013; (2) from the perspective of comprehensive pollution, the water quality of only five months in the reservoir was qualified and that of the rest months were in pollution, with severe pollution in 39 months, which resulted in the pollution index of annual average and water phase changing between pollution and severe pollution; (3) from the perspective of organic matter pollution, the water quality of the reservoir changed between the grade of good and relatively good, and that of 7 months was basically qualified, there was no organic pollution; the organic pollution index of annual average and water phase varied between the level of good and relatively good, and there was a tendency to organic pollution.

Key words: Zhangwu reservoir, environmental quality, water quality, single factor water quality identification index, comprehensive pollution index, organic pollution index, assessment