Author(s): Peng Lian; Zhao Min; Qian Bao

Linked Author(s):

Keywords: The Three Gorges Reservoir；nitrogen and phosphorus concentration；spearman rank correlation coefficient method；inter-annual variation；intra-annual variation

Abstract: In order to explore the impact of the operation of the Three Gorges Project on the nitrogen and phosphorus nutrient levels in the middle reaches of the Yangtze River over the past decade, based on the monitoring data of NH3-N and TP concentrations in the main stream of the Yangtze River from 2013 to 2022 at Yichang, Jianli, Luoshan, No. 37 Dock, Huangshi, Jiujiang, Chenglingji and Xiantao sections, the inter-annual variation trend of nitrogen and phosphorus concentrations in the main stream of the Yangtze River was explored by using the spearman rank correlation coefficient method. The results showed that the concentration of NH3-N in the middle reaches of the Yangtze River was at a relatively low level during the study period. Except for Jianli and Jiujiang sections, the other sections could meet the Class I water standard. The TP concentration in the middle reaches of the Yangtze River is basically in the Class III water standard, while the TP content in the section from Chenglingji and Xiantao is relatively low, reaching the Class II water standard. During the study period, the concentrations of NH3-N and TP in the middle reaches of the Yangtze River showed an overall significant downward trend.

DOI: https://doi.org/10.3850/iahr-hic2483430201-56

Year: 2024