BEIJING, April 14 (Xinhua) -- China saw visible progress in ecological environment protection as the quality of surface water and air continued to improve in the first three months of 2020, monitoring results from the Ministry of Ecology and Environment (MEE) showed Tuesday.

For 1,940 samples of surface water monitored by the ministry, the share of samples with a national quality rating at Grade III or above was 79.9 percent, up 5.6 percentage points year on year, the ministry said.

In the January-March period, 82.8 percent of the major rivers nationwide were of good quality, the ministry said.

The share of good air quality days in China's 337 cities hit 83.5 percent, up 6.6 percentage points year on year, with 120 cities nationwide meeting the air quality standards, 24 more than the same period of last year.

The average PM2.5 density in Beijing-Tianjin-Hebei and the neighboring regions went down 15.6 percent year on year, with the share of average good air quality days rising 10.9 percentage points to 59.6 percent, the ministry said.

The Yangtze River Delta, another one of the country's most economically vibrant regions, saw the share of average good air quality days increase to 86 percent, while the average PM2.5 density declined 26.2 percent from the previous year.