CHANGSHA - The phosphorus concentration at Dongting Lake, China's second-largest freshwater lake, has been falling continuously, indicating an improvement in its water quality, authorities said.

The total phosphorus concentration decreased to 0.06 mg per liter last year at the lake in Central China's Hunan province, down 17.8 percent from 2017, according to the provincial department of ecology and environment.

Hunan's water environment improved in 2020, with 93.3 percent of key river sections boasting good or excellent water quality, up 5 percentage points from 2017, according to the department, adding that air quality in the province has also improved.