The study looked at nitrogen and phosphorus pollution in rivers in Shanghai. They collected water samples from 11 rivers in 19 districts over a year. The rivers in Shanghai have different levels of pollutants, with suburban rivers having lower levels than urban ones. Rivers in the south have better water quality than those in the north. The concentration of pollutants is higher near Jiangsu Province compared to Zhejiang Province. Rainfall and tide can dilute pollutants in the rivers. After ecological restoration, the water quality of rivers improves.