Chinanews.com, September 16th, on the 16th of the Ministry of Ecology and Environment announced on the WeChat public account of the national surface water quality in August and January-August 2020.
Data show that in August 2020, among the 1940 national surface water assessment sections, the proportion of sections with good water quality (category Ⅰ-Ⅲ) was 71.3%, an increase of 0.9 percentage points year-on-year; the proportion of sections with poor grade V was 3.2%, a year-on-year decrease of 2.7 percentage point.
The main pollution indicators are total phosphorus, chemical oxygen demand and permanganate index.
National surface water quality category ratio in August 2020
From January to August 2020, among the 1940 national surface water assessment sections, the proportion of sections with good water quality (category Ⅰ-Ⅲ) was 81.0%, a year-on-year increase of 6.0 percentage points; the proportion of sections inferior to category V was 0.9%, a year-on-year decrease of 3.1 percentage points .
The main pollution indicators are chemical oxygen demand, total phosphorus and permanganate index.
National surface water quality category ratio from January to August 2020
Water quality status of main rivers
In August 2020, the seven major river basins including the Yangtze River, the Yellow River, the Pearl River, the Songhua River, the Huaihe River, the Haihe River and the Liaohe River, as well as the Northwest Rivers, Southwest Rivers, and Zhejiang-Fujian rivers, accounted for 74.6% of water quality sections, an increase of 1.3 year-on-year. Percentage points; 2.6% inferior to Category V, a year-on-year decrease of 2.8 percentage points.
The main pollution indicators are chemical oxygen demand, total phosphorus and permanganate index.
Among them, the water quality of the rivers in the northwest and southwest and the Yangtze River are excellent, the rivers in Zhejiang and Fujian and the Pearl River are of good water quality, and the Yellow River, Songhua River, Liaohe River, Haihe River and Huaihe River are lightly polluted.
From January to August 2020, the seven major river basins including the Yangtze River, the Yellow River, the Pearl River, the Songhua River, the Huaihe River, the Haihe River, and the Liaohe River, as well as the Northwest Rivers, Southwest Rivers, and Zhejiang-Fujian rivers, accounted for 84.9% of water quality sections in Grade I to III, an increase from the previous year 6.7 percentage points; 0.6% inferior to category V, a year-on-year decrease of 3.6 percentage points.
The main pollution indicators are chemical oxygen demand, permanganate index and five-day biochemical oxygen demand.
Among them, the water quality of the rivers in the northwest, the Yangtze River, the Zhejiang-Fujian rivers, the southwestern rivers and the Pearl River are good, the water quality of the Yellow River and Songhua River are good, and the Huaihe, Liaohe and Haihe rivers are lightly polluted.
Water quality and nutritional status of important lakes (reservoirs)
In August 2020, among the 112 key lakes (reservoirs) monitored, the number of lakes and reservoirs with Grade I-III water quality accounted for 69.6%, an increase of 5.1 percentage points year-on-year; the number of lakes and reservoirs with water quality inferior to Grade V accounted for 8.0% , A year-on-year decrease of 0.4%.
The main pollution indicators are total phosphorus, chemical oxygen demand and permanganate index.
Among 104 key lakes (reservoirs) monitored for nutritional status, 7 lakes (reservoirs) were in a moderate eutrophication state, accounting for 6.7%; 24 lakes (reservoirs) were in a mild eutrophication state, accounting for 23.1%; the remaining lakes ( Library) did not show eutrophication.
Among them, Taihu Lake is mildly polluted and mildly eutrophic, and the main pollution indicator is total phosphorus; Chaohu Lake has good water quality and mild eutrophication; Dianchi Lake is moderately polluted and moderately eutrophic. The main pollution indicators are chemical oxygen demand, total Phosphorus and permanganate index; Erhai Lake has good quality and medium nutrition; Danjiangkou Reservoir has excellent and medium nutrition water quality; Baiyang Lake is moderately polluted and mildly eutrophic. The main pollution indicators are chemical oxygen demand, total phosphorus and permanganic acid Salt index.
Compared with the same period last year, the water quality of Dianchi Lake has declined, the water quality of Taihu Lake has improved, the water quality of Chaohu Lake has improved significantly, and the water quality of Erhai Lake, Danjiangkou Reservoir and Baiyangdian Lake have not changed significantly; the nutritional status of Baiyang Lake has improved, Taihu Lake, Chaohu Lake, Dianchi Lake, Erhai Lake and Danjiangkou have improved. There was no significant change in the nutritional status of the reservoir.
From January to August 2020, among the 112 key lakes (reservoirs) monitored, the number of lakes and reservoirs with Grade I-III water quality accounted for 73.2%, an increase of 4.1% year-on-year; the number of lakes and reservoirs with water quality inferior to Grade V accounted for 73.2% 5.4%, a year-on-year decrease of 1.9 percentage points.
The main pollution indicators are total phosphorus, chemical oxygen demand and permanganate index.
Among the 109 key lakes (reservoirs) monitored for nutritional status, 1 lake (reservoir) was in a severe eutrophication state, accounting for 0.9%; 6 lakes (reservoir) were in a moderate eutrophication state, accounting for 5.5%; 25 lakes ( Reservoir) showed mild eutrophication, accounting for 22.9%; the remaining lakes (reservoirs) did not show eutrophication.
Among them, Taihu Lake is mildly polluted and mildly eutrophic, and the main pollution index is total phosphorus; Chaohu Lake has good water quality and mild eutrophication; Dianchi Lake is moderately polluted and moderately eutrophic. The main pollution indicators are chemical oxygen demand, total Phosphorus and permanganate index; Erhai Lake and Danjiangkou Reservoirs have excellent water quality and moderate nutrition; Baiyangdian Lake is lightly polluted and mildly eutrophic. The main pollution indicators are chemical oxygen demand, total phosphorus and permanganate index.
Compared with the same period last year, the water quality of Dianchi Lake has declined, the water quality of Chaohu Lake and Erhai Lake has improved, and the water quality of Taihu Lake, Danjiangkou Reservoir and Baiyang Lake has not changed significantly; the nutritional status of Dianchi Lake has declined, and Taihu Lake, Chaohu Lake, Erhai Lake, Danjiangkou Reservoir and Baiyang Lake have no obvious changes. obvious change.
National surface water assessment section ranking of cities at prefecture level and above
The cities at prefecture-level and above participating in the ranking cover 2050 state-controlled sections (of which 1940 are national surface water assessment sections and 110 are sea-controlled sections).
In August 2020, among the national prefecture-level and above cities, 30 cities including Laibin, Liuzhou, and Yunfu have relatively good water quality in the national surface water assessment sections (from 1st to 30th), Heze, Cangzhou and Shangqiu, etc. The water environment quality of the national surface water assessment sections of 30 cities is relatively poor (from the bottom to the bottom 30); from January to August 2020, among the national prefecture-level and above cities, 30 cities including Zhangye, Liuzhou and Jinchang The water environment quality of the national surface water assessment sections in cities is relatively good (from the 1st to the 30th), and the water environment quality of the national surface water assessment sections in 30 cities including Tongchuan, Cangzhou and Xingtai is relatively poor (from the bottom 1st to the 30th). 30th from the bottom).