Topic 1 Caring for Water Resources

Unit 4 Water in Nature 

Topic 1

Caring for Water

Water is one of the most common and common substances on earth, not only in rivers, lakes and seas, but also in various organisms.

Water is needed for the birth and maintenance of life; human daily life and industrial and agricultural production cannot do without water; hydropower uses water; in addition, water can also provide waterway for human beings and a pleasant environment.

1. Human-owned water resources

The total water reserves of various forms such as ocean water, lake water, river water, groundwater, atmospheric water and biological water on the earth are about 1.39x1018m3, and about 71% of the earth's surface is covered by water.

The ocean is the largest water reservoir on the earth, and its water storage accounts for about 96.5% of the world's total water storage. The vast ocean not only breeds countless aquatic organisms, but also contains rich chemical resources. According to current measurements, the chemical elements contained in seawater There are more than 80 kinds. As a chemical substance, water can participate in many reactions and is itself a chemical resource.

2. Caring for water resources

Water is an essential substance for the survival of all living organisms. For the sustainable development of human beings and social economy, we must protect water resources. On the one hand, we must save water, and on the other hand, we must prevent and control water pollution.

To save water resources is to improve water utilization efficiency. Using new technologies, reforming processes and changing habits can greatly save industrial, agricultural and domestic water.

Water pollution refers to the discharge of a large amount of pollutants into the water body, which exceeds the self-purification capacity of the water body, deteriorating the water quality, destroying the ecological balance of the water body and its surroundings, and causing losses and threats to human health, life and production activities. The sources of water pollution mainly include industrial pollution, agricultural pollution and domestic pollution.

Water pollution not only affects industrial, agricultural and fishery production, destroys aquatic ecosystems, but also directly endangers human health. Therefore, various measures must be taken to prevent and control water pollution, protect and improve water quality. For example, in industry, the generation of pollutants is reduced through the application of new technologies and new processes, and at the same time, the polluted water bodies are treated to meet the discharge standards. In agriculture, the use of farm manure and the rational use of chemical fertilizers and pesticides are advocated. Domestic sewage should also gradually realize centralized treatment and discharge.

You should know after finishing this topic

1. The water reserves on the earth are abundant, but the available fresh water resources are limited.

2. For the survival and development of human beings, human beings must cherish water - save water, protect water and prevent water pollution.