Water is the source of life, the basis of life, and human health cannot be separated from water. People can not eat for a few days, but not a few days without water. And now, 2 billion people around the world are in a serious water shortage! The water crisis has sounded an alarm to mankind!
China's water resources, although relatively abundant, but most of the water is seawater, and seawater is salty, is not directly drinkable; coupled with most of the fresh water are distributed in the cold south and north poles and year-round snow on the mountains, so that the fresh water resources left little. And the distribution is uneven, more in the east and less in the west, more in the south and less in the north, there are many places where water is scarce.
When I was a child, I thought, "Isn't the water from the tap always flowing? Mom and Dad often tell me which places have recently had a drought, not to mention planting crops, that is, it is difficult to ensure that people drink the water. I always find it inconceivable that water is not the most abundant thing on earth? Big rivers, big rivers, big lakes, the sea is not so much? How can there be a shortage of water!
Later, I slowly grew up, but also slowly figure out: water is the source of all life on Earth. The total amount of water on Earth is 18 trillion billion liters. This amount seems to meet the global population's demand for water, but the reality is not encouraging. Ninety-nine percent of the existing water reserves are seawater and polar ice, which are not suitable for human use; the remaining 1% is still mostly in the strata below 800 meters, and the water in rivers and lakes, on which people depend for their survival, accounts for only 0.01% of the total. There are already 18 countries in the world with less than 1,000 cubic meters of renewable water resources per capita. According to a report by the World Resources Institute, 3.4 billion people in the world have access to an average of only 50 liters of water per year, marking a crisis of freshwater scarcity for humanity.
This grim situation has not attracted enough attention, and the rivers and lakes on which people depend for their survival are facing the threat of more and more pollution. Only by eliminating pollutants into the rivers and lakes, or reduce their number, the original pollutants in the rivers and lakes will flow away with the water, dilution, and gradually reduce. Therefore, the most fundamental way to prevent and control pollution in rivers and lakes is to control the sources of pollution. We know that the sources of pollution in rivers and lakes are industrial wastewater and urban and rural sewage. The state has formulated a series of laws and regulations to protect water resources, wastewater discharge and other aspects, have made strict restrictions and regulations.
If we do not cherish water resources, the last drop of water flowing down from the earth in the future will be our own tears.