Introduction
The selection of water quality index directly affects the results of water quality assessment [1, 2]. For
decades, countries across the globe have been in a constant battle developing the most suitable method to
assess the health of water. In China’s surface water environment management work, the monitoring and
assessment of water quality are usually required to be accordance with 24 indexes in Table 1 in theEnvironment Quality Standards for Surface Water (GB3838-2002). However, in fact, due to the great
difference between the polluted characteristics of south and north water bodies, main river and its
tributaries, the adoption of “One-cut” assessment and evaluation index system will cause repeated
monitoring of some less polluted indexes, which would lead to a waste of human resources, materials and
financial resource [3, 4]. Therefore, choosing an effective monitoring and assessment index, on the
condition that the result of water quality assessment is accurate, is always the key content of river water
quality evaluation method optimization.