The researchers studied sediment phosphorus in reservoirs of the Huangbai River to understand pollution levels. They found high total phosphorus concentrations in the basin, indicating heavy pollution. Phosphorus fractions showed a consistent pattern across sites. Phosphate flux across sediment-water surfaces ranged from 0.0179 to 0.1825 mg·(m2·d)-1, decreasing downstream. The flux was linked to HCl-P, OP, and TP levels in the highly polluted basin.