Huai He River
Huaihe River Basin includes 35 cities in Henan, Anhui, Shandong and Jiangsu provinces, with a basin area of 270,000 square kilometers. Ammonia nitrogen has become the primary pollution factor in Huaihe River Basin.
2.haihe river
Haihe river basin is one of the basins with the highest degree of water resources development and the most serious water pollution in China. Water environment problems in river basins are complex. Chemical oxygen demand, ammonia nitrogen and total phosphorus are the main pollution factors, and other factors exceeding the standard include permanganate index and petroleum.
3. Liaohe River
The total area of Liaohe River Basin is 22 1, 1, 000 square kilometers. Except for Xiliao River water resources area, the water quality data of 47 state-controlled sections in the whole basin show that ammonia nitrogen has become an important pollution factor leading to a relatively low water quality compliance rate in the whole basin. The total nitrogen and total phosphorus in some reservoirs in the basin seriously exceed the standard, and some reservoirs have serious eutrophication problems.
4. Taihu Lake
Taihu Lake is the third largest freshwater lake in China, with a total basin area of 36,900 square kilometers. There are more than 0/00 rivers around the lake, of which about 60% enter the lake.
Taihu Lake has many functions in the basin, such as drinking water, industrial and agricultural water, shipping, tourism, flood control, storage and so on. It is an important water resource for social and economic development in the Yangtze River Delta.
5.chaohu lake
Chaohu Lake is one of the "three lakes and three rivers" that China has been focusing on. In 1970s, Chaohu Lake was polluted by "water bloom" for many times, and since 2004, it has reached Class V of the whole lake, and the deterioration trend of water quality is very severe. In 2009, among the main rivers around Chaohu Lake Basin 10, only Yuxi River reached the water quality standard, and the water quality category was Class III. Nine rivers fail to meet the standards, and the main factors exceeding the standards are COD, ammonia nitrogen, total phosphorus and petroleum. The overall nutritional status of Chaohu Lake is mild eutrophication.
6.dianchi lake
Dianchi Lake belongs to the Yangtze River basin and is located at the watershed of the Yangtze River, the Red River and the Pearl River. Dianchi Lake is one of the important "three lakes" in China. Since 1990s, the nutrients TN and TP in Dianchi Lake have increased year by year. In 2009, the water quality off Caohai and Dianchi Lake was worse than Grade V. ..
7. Songhua River
Songhua River Basin covers most of Heilongjiang Province and Jilin Province, the eastern part of Inner Mongolia Autonomous Region and parts of Liaoning Province, covering 26 cities (prefectures and leagues), with a total basin area of about 5610.2 million square kilometers. The main pollution factors affecting the water quality exceeding the standard are permanganate index, chemical oxygen demand and fecal coliform. Ashe River and Yitong River are still inferior to Class V. ..
8. Three Gorges Reservoir
The dam site of the Three Gorges Reservoir is located in Sandouping, Xiling Gorge of the Yangtze River, starting from Yichang, Hubei Province in the east and reaching Baxian County, Chongqing in the west, involving 20 counties (cities, districts). The water quality in the reservoir area is mainly Class I and II water, the tributaries in the reservoir area are mainly Class II and III water, and the outlet section of the Yangtze River is mainly Class I and II water. The water quality of Wujiang River and Jialing River entering the mainstream of the Yangtze River has reached Class II water quality standards. The water quality of Jinsha River reaches Grade II; The water quality of Chishui River entering the mainstream of the Yangtze River reaches Grade II or above.
9. Middle and upper reaches of the Yellow River
The basin covers an area of 734,000 square kilometers. During the Eleventh Five-Year Plan period, the permanganate index and the average concentration of ammonia nitrogen in the main stream of the Yellow River showed a downward trend, which met the Class III water quality standard, and the dissolved oxygen reached the Class II water quality standard. The water quality of Xiaheyan (Ganning) and Lasengmiao (Ningmeng) sections in Zhongwei has been obviously improved, which can meet the Class III water quality standard. However, during the 11th Five-Year Plan period, the water quality of the tributaries Huangshui River and Xiao Xia Bridge of Huangshui River was worse than Grade V water quality for five consecutive years.
10. Water source and along the South-to-North Water Transfer Project (Danjiangkou reservoir area and its upstream)
During the "Eleventh Five-Year Plan" period, measures such as water pollution prevention and soil erosion control in the water source area of the middle route of South-to-North Water Transfer Project have achieved initial results. The water quality of seven sections in Danjiangkou reservoir area has reached Class II water standard.
The assessment indicators of water quality in key river basins include four categories: one is water temperature, pH value, dissolved oxygen, permanganate index, chemical oxygen demand, five-day biochemical oxygen demand, ammonia nitrogen, copper, zinc, fluoride, selenium, arsenic, mercury, cadmium and chromium except for the three indicators in Table 1 of Environmental Quality Standard for Surface Water. Second, eutrophication indicators, including total nitrogen and total phosphorus; The third is fecal coliform index; The fourth is the characteristic pollutant index of the basin. The above four types of indicators are assessed separately, and rivers are not assessed as eutrophication indicators.