Water breeds life and human civilization on the earth, and people's life and industrial and agricultural production are inseparable from water. If there is no water, people will disappear. On earth, where there is water, there is life. All life activities originate from water. Water in human body accounts for about 65% of body weight. Without food, people can live for a long time (estimated to be two months). If there is no water, they can live for a week at most. Plants also contain a lot of water to transport nutrients for plants; Water keeps the branches and leaves of plants elegant; Water participates in photosynthesis to produce organic matter; The evaporation of water keeps plants at a stable temperature to avoid being burned by the sun. Plants are not only covered by water, but also crops consume water all their lives. 1 kg corn is irrigated with 368 kg water; Similarly, wheat is 5 13 kg water, cotton is 648 kg water, and rice is as high as 1000 kg water. One seed falls to the ground, ten thousand grains are put into storage, and agriculture gains a lot. Water has made a lot of contributions!
Some people say that our earth should be called water polo. This makes sense, because the planet we live in has water, and 7 1% of its surface area is occupied by water. The earth has a huge amount of water, totaling 13. 8.6 billion cubic kilometers. Although there is a huge amount of water on the earth, it is pitiful that it can be directly used for production and life. First of all, seawater is salty and bitter, so it can't be drunk, irrigated or used for industry. Secondly, fresh water only accounts for 2% of the total water. About 6%, most of them (99%) are frozen in the frozen soil at the north-south level and far away from human beings, and cannot be used. Less than 65,438+0% of fresh water is scattered in lakes, rivers and underground. Compared with all the water bodies in the world, the quantity of fresh water is actually nine Niu Yi hairs.
With so little fresh water, people also waste water resources extremely. The World Summit on Sustainable Development held in South Africa not long ago listed the water crisis as one of the most serious challenges facing mankind in the future 10. According to the materials released at the conference, there are currently 2.4 billion people in the world who lack adequate water sanitation facilities, and 1, 65.438+0 billion people cannot drink safe drinking water. The United Nations predicts that by 2025, nearly half of the population will live in water-deficient areas, and the water-deficient or water-deficient areas are expanding. Nowadays, people are less and less saving water. Maybe when the radio will sound an alarm like this: "In four months, the water will disappear." At that time, it was discovered that the price of a drop of water was equivalent to the price of a drop of blood. What a terrible thing.
Therefore, saving water and protecting water resources have become the top priority now! Each of us should start with me, from now on. For example: 1, rice washing water can be used for washing face, watering flowers, mopping floor and flushing toilet; Don't leave the shower nozzle on all the time, but let the water shower intermittently. Turn off the water in time when scrubbing; 3, clothes should be washed centrally, reducing the number of laundry; Moreover, advocating hand washing for small items such as underwear, socks and summer clothes can save a lot of water. A proper amount of detergent should be put into the washing machine. Excessive dosage will lead to unclean washing and waste a lot of water.
I hope everyone can take action and take some measures to save water and make the earth full of vitality!
Water is the source of life.
Water is the source of life. With the increase of human demand for water, the pollution of water resources is more serious, which has formed a crisis that cannot be ignored.
The first is the crisis of water resources, mainly referring to the crisis of water "quantity". It is estimated that the total volume of water on the earth is about 13. 800 million cubic kilometers, but 87% of them are polar ice sheets, alpine glaciers and ice and snow in permafrost areas that are difficult to use. What humans can really use is a part of rivers, lakes, oceans and groundwater, accounting for about 0. 26%, so the world's fresh water resources are extremely limited. In China, the prospect of water resources is not optimistic. The total amount of water resources in China is about 2. 800 million cubic meters, ranking sixth in the world. The per capita possession is 340 cubic meters, accounting for only 1/4 of the world's per capita possession. The world ranking 109 is listed as one of the water-poor countries in the world 13. 18 provinces (autonomous regions and municipalities directly under the central government) per capita water consumption is lower than the national average. China's urban water shortage is 6 billion cubic meters. Among the more than 640 cities, there are more than 300 cities short of water, including 108 cities with severe water shortage. Due to water shortage, many cities such as Tianjin, Shanghai, Changzhou and Xi have been overexploiting groundwater for a long time, which has led to the rapid expansion of groundwater funnels, land subsidence and seawater intrusion. In rural China, 65 million people and 60 million livestock have difficulty drinking water. By the year 2000, China will be short of at least 60 billion cubic meters of water, and the shortage of water resources has become a "bottleneck" restricting China's social progress and economic development.
Secondly, the water environment crisis mainly refers to the crisis of water quality change caused by the increasingly serious water pollution, which has brought many adverse effects on human production and life. The earth discharges about 500 billion tons of sewage every year, 90% of which is untreated. Water pollution is the most serious in developing countries. The wastewater discharged from Malaysian oil refineries and rubber factories turned 42 rivers in China into dead rivers. Two-thirds of India's water sources are seriously polluted; Industrial wastewater in Pakistan pollutes all rivers in cities and villages; Two1and 13 rivers in Chile and Peru in Latin America are seriously polluted by industrial wastewater. The Songhua River, Liaohe River, Yellow River, Huaihe River, Haihe River, Yangtze River and Pearl River in China are all polluted to varying degrees.
Due to the increasingly serious pollution of fresh water resources, people's production and living environment has been seriously damaged. According to the statistics of the World Health Organization, there are currently 2.9 billion people in the world who have no access to clean drinking water. At least150,000 people worldwide die of diseases caused by water pollution every year, most of them are children. Diarrhea alone causes 40,000-50,000 infant deaths every year. Because of water pollution, the beauty of the river no longer exists. The once pleasant environment has become unbearable.
Biological evolution begins with water, and water bears the important mission of ecosystem stability and biological evolution. Mankind's wanton occupation of water areas, over-exploitation and pollution of water resources have changed the living conditions of aquatic organisms, causing a large number of aquatic organisms to lose their living environment and go extinct, fundamentally destroying the stability of the ecosystem and bringing great harm to human beings themselves. For example, the construction of dams and river gates that human beings are proud of has destroyed the continuity of rivers and blocked the passage of migratory fish; Channelization of the river makes the water flow conditions uniform, and all kinds of water flow conditions needed by various organisms disappear; The increasing water pollution has degraded the ecological species in the waters, and many species have become extinct.
Students, when you see the endless green forest cut down by those cruel hands and turned into wasteland; When you see the pure water around you being wasted, when you see something delicious being slapped away ... Does it hurt? When I read a book "Cherish Resources and Advocate Saving", my heart was shaken; It turns out that the earth's resources are limited, and she can't give us everything we need forever! If we don't save, what will our children and grandchildren eat? With what? What to drink?
When I was watching TV, I once saw an advertisement that many people died in an area because of serious water shortage, and even children could not go to school. At present, many places in Shanghai have changed toilets in order to save water. Now I especially regret the original waste behavior, so I wrote on our blackboard: Save water resources from now on! In the evening, I said to my parents, "Mom and Dad, let's start saving water today!" " ! I read a book today. Many children in mountainous areas are dying because of lack of water. If a family can save one bowl of water a day, it can save 30 bowls of water a month and a lot of water a year. For those families who are short of water, this water can be said to be a life-saving spring. "Mom and dad listened and nodded.
One day, I saw a water pipe leaking at home, so I quickly found a basin to pick up the crystal beads. At the end of the day, the basin is full of water. I will wash my face with this water, then flush the toilet and water the flowers. If it weren't for my heart, wouldn't the water be wasted?
Now many families have bought cars, and in order to keep them clean, they spend money to wash them. Whenever I pass by the car wash shop and see the clear fountain-like water flowing along the traffic and wasting on the road, I will think of the scene that people in water-deficient areas are eager to drink water. I think: if these people carry a bucket of water and scrub it with a towel, how much water will they save? How many children will be bathed in water-deficient areas?
Students, cherish every drop of water! Water is the source of our life. Without water, human beings can't live!
Water-the source of life
Water is the source of life. Without it, everything will cease to exist. Water is the most needed substance for human beings. Without it, mankind will also face extinction. It can be seen that water is closely related to our life.
The ancients thought that water was an inexhaustible gift from heaven, but facts speak louder than words. According to statistics, the global fresh water resources are only 350 million cubic meters, and only 0.34% of this limited fresh water resources can be used by human beings. Due to uneven distribution and waste of life, 60% of the world is short of water, which is serious and the situation is grim.
At present, China is also facing a huge water crisis. In addition, the number of people has gradually increased, and the water supply has also increased. In addition, the severe drought in recent years has led to frequent water cuts. Many vegetable fields planted by farmers died because there was no rain irrigation, and the national vegetable production decreased to the extreme. But people still don't realize the importance of water, and they still waste it at will.
On the way to school, I often see a hotel worker washing vegetables, only to see him turn on the tap at full speed, put the vegetables under the tap and leave. It was a long time before he came back to take the food away, but he didn't turn off the tap, and a lot of domestic water flowed into the drain pipe, which caused great waste.
In the past, we could always see Qingshui River wandering in the river. Now, what we see is a garbage river full of garbage and industrial waste. With the development of modern science and technology, there are so many abandoned industrial wastes that even the ponds in the park are doomed. In this way, the survival of mankind is more threatened.
Faced with such a huge threat, we should learn to save. If each of us saves a glass of water, the world will save the next river. How many rivers and seas will we save in the long run!
Protect the blue sky and blue sea and create a beautiful home. Let's join hands to contribute to the protection of water resources and lend a helping hand to national construction.