Surface water refers to the general term of dynamic and static water on the land surface, also known as "land water", including various liquid and solid water bodies, mainly rivers, lakes, swamps, glaciers, ice caps, etc. . It is one of the important sources of water for human life and the main component of water resources in various countries.
On May 7, 2019, the Ministry of Ecology and Environment announced the first-quarter national surface water assessment cross-sectional water environment quality ranking list, notifying the first-quarter national water environment quality and completion of target tasks.
The dynamic quantity of surface water is river runoff and glacier runoff, and the static water quantity is expressed by the storage capacity of various water bodies. The world ’s surface water reserves are 24,254 trillion cubic meters, accounting for only 1.75% of the world ’s total water reserves; however, surface water bodies are constantly recharged by atmospheric precipitation. After production and confluence, there are 43.5 trillion cubic meters of river runoff and 23,000 annually. One hundred million cubic meters of glacial runoff flows into the ocean, accounting for 94.7% of the total of 47 trillion cubic meters, and plays a very important role in the global water cycle. In addition, the inflow area generates 1.0 trillion cubic meters of river runoff annually, which is fed into inland lakes and consumed for evaporation. The shape of surface water is closely related to climate. Of the 149 million square kilometers of land in the world, about 62% of the area is covered by rivers, lakes and swamps, about 12% is covered by glaciers, and the remaining 26% is desert and semi-desert.
Cause of formation
Surface water is accumulated through years of natural precipitation and snow, and it naturally drains into the ocean or disappears through evaporation and seeps into the ground.
Although the natural water source of any surface water system only comes from precipitation in the catchment area, there are still many other factors that affect the total amount of water in this system. These factors include lakes, wetlands, reservoir water storage capacity, soil seepage, and the characteristics of surface runoff in this catchment area. Human activities have a significant impact on these characteristics. Humans build reservoirs in order to increase the amount of stored water, and let out the wetland water in order to reduce the amount of stored water. Human reclamation activities and the construction of ditches increase the amount and intensity of runoff water.
Surface water exists on the surface of the earth's crust and is exposed to the atmosphere. It is the general name of four water bodies such as rivers, glaciers, lakes and swamps, also known as "land water". It is one of the important sources of water for human life and the main component of water resources in various countries.
Laws and regulations and standards
Water Law of the People's Republic of China
On January 21, 1988, the Standing Committee of the Sixth National People's Congress of the People's Republic of China passed the Water Law of the People's Republic of China. The main contents are: ① Adjustment range. To develop, use, protect, and manage water resources in the territory of the People's Republic of China, and to prevent and control water hazards, it is necessary to abide by the Water Law. Water resources include surface water and groundwater. ② Clear ownership of water resources, that is, water resources belong to the whole people and collective ownership. ③Strengthen the management of water resources utilization through the collection of water fees and water resources fees. ④Strengthen the government's leadership in flood control and flood control work, and stipulate the measures that flood control command agencies can take in emergencies.
The 29th meeting of the Standing Committee of the Ninth National People ’s Congress of the People ’s Republic of China revised and adopted the new version of the “Water Law of the People ’s Republic of China” on August 29, 2002. It will take effect on October 1.
Environmental Protection Law of the People's Republic of China
The Environmental Protection Law of the People ’s Republic of China is a national law formulated to protect and improve the environment, prevent pollution and other public hazards, protect public health, promote the construction of ecological civilization, and promote sustainable economic and social development. The 12th National People ’s Representative of the People ’s Republic of China The eighth meeting of the Standing Committee of the General Assembly was revised and approved on April 24, 2014. The revised "Environmental Protection Law of the People's Republic of China" is now promulgated and will take effect on January 1, 2015.
Surface water environmental quality standards
In order to implement the "Environmental Protection Law" and "Water Pollution Prevention Law", strengthen the management of surface water environment, prevent and control water environment pollution, and protect human health, the "Surface Water Environmental Quality Standard" is now approved as the national environmental quality standard. The General Administration of Quality Supervision, Inspection and Quarantine issued jointly.
On May 7, 2019, the Ministry of Ecology and Environment announced that the top five cities in the first quarter of the national surface water assessment cross-sectional water environment quality are: Ya'an, Laibin, Yunfu, Jinchang, and Wuzhou. The bottom 5 cities (from 1 to 5) are: Luliang, Yingkou, Xingtai, Liaoyuan, Jinzhong. The changes of surface water environment quality in the surface water assessment sections of 30 cities such as Siping, Changchun, and Zhongshan are relatively good, while the changes in surface water environment quality of the surface water assessment sections of 30 cities such as Luliang, Yingkou, and Shuozhou are relatively poor.
On May 7, 2019, the Ministry of Ecology and Environment also notified the national water environment quality and completion of the target tasks in the first quarter. The overall quality of the water environment in the country has improved. Among the 1940 national surface water evaluation sections, the proportion of good water quality sections is 74.3%, an increase of 8.0 percentage points year-on-year; the ratio of inferior category V sections is 6.0%, a decrease of 3.6 percentage points year-on-year. The main pollution indicators are ammonia nitrogen, total phosphorus and chemical oxygen demand. The work of water pollution prevention and control is uneven, and the situation of meeting the water environment standards in some areas is still grim.