Water quality assessment and spatial‐temporal change: The case of Zipingpu Reservoir in central Sichuan Province, China

Abstract

AbstractThis research evaluated and analyzed the water quality of Zipingpu Reservoir using the Comprehensive Water Quality Index and Nemerow index method, based on monitoring data from 2019 to 2021 at four monitoring sites. It also used temporal and spatial change rate analysis to understand changes in water quality among the four monitoring sites—Aba Aluminum Factory, Chaguan Village, Cross‐reservoir Bridge and Xuankou Village—as well as the reservoir as a whole. The results show that: from the result of comprehensive water quality index, the water quality of Zipingpu Reservoir had improved in 3 years, and the water quality was excellent. The Nemerow index method results for the four monitoring sections in 2019, 2020, and 2021, which varied from 0.37 to 0.47, demonstrated that the reservoir was rated as having high water quality and Class I standard water quality. According to the results of the improved Nemerow pollution index method, the Improved Nemerow pollution index values were all between 0.27 and 0.32 and the water quality was within the Class I range each of the 3 years and fluctuated less. The water quality of the Aba aluminum facility was marginally worse than that of the other three monitoring sites during the monitoring period, according to the spatial rate of change (S/%). The reservoir's water quality improved slightly between 2019 and 2021, according to the temporal rate of change (T/%).