Changes in China’s river water quality since 1980: management implications from sustainable development

This study simulates monthly concentrations of riverine total nitrogen (TN), ammonia-nitrogen (NH₄-N), total phosphorus (TP), and chemical oxygen demand (CODₘ) in 613 sub-watersheds of China's 10 major river basins from 1980-2050. Using a 16-year monitoring dataset and stacking machine-learning models, the results show marked water quality improvement except for TN, possibly due to lacking control targets and assessment systems. Anthropogenic factors were the primary controls on TN, TP, and NH₄-N concentrations. The study suggests considering water resources, environment, ecology, and security collectively to improve China's river ecological status, aligning with the 17 sustainable development goals (SDGs) relevant to water quality.

Hanxiao Zhang, Xianghui Cao, Shouliang Huo, Chunzi Ma, Wenpan Li, Yong Liu, Yingdong Tong, Fengchang Wu