Temporal and Spatial Variation of water quality in the Yongding River Basin

Abstract For exploring the water quality and macroinvertebrate community characteristics of the Yongding River Basin, investigation of water environment and macroinvertebrates was conducted in 34 sampling sites in August 2016 and April 2017. Furthermore, Water Quality Index (WQI) and biological index (BI) were used to assess the water quality of studied rivers. According to the water quality evaluation results of the WQI and the BI method, the water quality of most sites in non-flood season were equal to or better than those in flood season, and these sites were mostly located in urban area. The dominant land use and non-point source pollution was the primary contributor to water quality degradation in rural areas. There are both similarities and differences between BI index and water quality identification index. From the evaluation results of Sanggan River, Yanghe River and Yongding River, the water quality of Yanghe River is better than that of Sanggan River and Yongding River.