Assessing water quality for urban tributaries of the Three Gorges Reservoir, China

Abstract

Water quality assessment is essential for water resources management. This paper presents a comprehensive evaluation of water quality conditions in three urban tributaries of the Three Gorges Reservoir, China. The Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) and Nemerow Pollution Index (NPI) approach were used in this study. Generally, the assessment results of the NPI approach are consistent with that of the CCME-WQI approach. However, the NPI method overemphasized the influence of the most serious pollutant factor, and thus this method should be used with caution for water resources managers. The CCME-WQI values indicated that the water quality conditions in the Wubu River were quite good during the period 2013–2015. Water quality conditions in the upstream sections of Yipin and Huaxi River are good. However, when the river drains through urban areas, water quality conditions greatly deteriorate due to the excessive release of household and municipal sewage, and industrial wastewater, especially for Huaxi River. Thus, waste water management becomes more and more imperative in urban regions of China. Meanwhile, assessment results indicate that the CCME-WQI approach can provide a reference for decision-makers on water resources management.

Keywords

• CCME-WQI
• NPI
• Three Gorges Reservoir
• urban rivers
• water quality