Saving water is our common responsibility. The themes of World Water Day and China Water Week are "Sanitary Water Use" and "Strengthening Conservation and Protection to Realize Sustainable Utilization of Water Resources" respectively. Looking at this theme, we can't help but think of the famous aphorism: If we don't cherish the precious water resources, then the last drop of water on the earth is probably our tears! Water resource is a "crisis" faced by human society, one of the important resources for human survival and development, and an indispensable and irreplaceable special resource. Without water, there would be no life, no civilization progress, no economic development and no social stability. The water resources in the world are limited, so the economic and social development must adapt to the water supply, and the water cannot be used indefinitely or exceed the carrying capacity of water resources. In today's world, with the continuous growth of population and economic development, the demand for fresh water resources is increasing day by day; At the same time, due to unreasonable utilization, the shortage of fresh water resources is increasingly tense. China has been short of water for a long time. Historically, China is a country with frequent droughts, known as "nine droughts in ten years". In the historical documents of more than 2200 years, there have been 1300 droughts. China's per capita water resources are only about 2,300 cubic meters, which is about a quarter of the world's per capita water. Water resources in China are not only less per capita, but also unevenly distributed. The basin area north of the Yangtze River accounts for 63.5% of the land area, while water resources account for 19% of the whole country. In addition to China, there are many countries and regions in the world with serious water shortage problems. The United Nations Water Conference pointed out: "We are entering a new era of water shortage". The increasingly serious global water crisis has aroused great concern of the international community. 1972 United Nations Conference on Human Environment and 1977 United Nations Water Conference warned the world: "Water will soon become a serious social crisis, and the next crisis after the oil crisis is water." Countries all over the world have begun to pay unprecedented attention to water problems, and gradually formed a * * * understanding of water crisis. 1In August, 1995, the World Bank survey report announced that 26 countries, accounting for 40% of the world's population, were facing water crisis, and their agriculture, industry and people's health were seriously threatened; About 654.38 billion people in developing countries do not have access to clean water, 654.38 billion people do not have good sanitation facilities, 80% of diseases are caused by drinking unclean water, and 25 million people die every year. Saving water is an inevitable choice for sustainable development. The Agenda Declaration 2 1.70 adopted by 65,438 heads of state and government at the Rio Conference on Environment and Development put forward the strategy of sustainable development, pointing out that "water is not only necessary to maintain all life on the earth, but also of vital significance to all social and economic sectors." China took the lead in formulating "China 2 1 Century Agenda", and explicitly included sustainable development as a national development strategy in the Ninth Five-Year Plan and the 20 10 development plan of national economy and society. Among them, water-saving work, as an important strategic decision of the CPC Central Committee and the State Council, has been included in the agenda of governments at all levels, and the concept of water-saving has been deeply rooted in people's hearts step by step. ? The demand for water in the economic development of northern China shows an upward curve in the future development chart, and the implementation of the strategy of developing the western region is even more indispensable. It has become an inevitable choice for China's economic development to develop water resources rationally and save water. Saving water is our common responsibility. It can be said that through years of efforts, China has made great progress in water conservation, but compared with some developed countries, we still have a long way to go. Agriculture is a big water user and a great waste of water resources. At present, the agricultural irrigation mode of "soil canal water conveyance plus flood irrigation" is still widely used in China. Half of the irrigation water is lost in the water conveyance, and the irrigation water utilization coefficient is mostly only 0.4, which is less than half of that of some developed countries. After irrigation with water per square meter, the grain yield in China increased by 0.5 kg, and that in developed countries could reach 2 kg. Industry, due to the backward technology of existing water facilities, the current water consumption per 10,000 yuan of industrial output value in China is 103 cubic meters, 8 cubic meters in the United States and only 6 cubic meters in Japan, which is 10 ~ 20 times that of developed countries; The reuse rate of industrial water in China is only about 40%, while the average level in developed countries is 75% ~ 85%. The phenomenon that urban residents don't talk about saving and waste domestic water is very serious, and water-saving education has a long way to go. Beijing alone leaks 360,000 tons of water every year. In Israel, which is also short of water, there are not only two sets of pipes for residents to flush toilets and wash their hands, but also two buttons for defecation. It was the Israelis with a strong sense of water crisis who invented the agricultural drip irrigation technology. From now until the middle of the next century, it will be a period for China to fully realize the grand goal of socialist modernization. With population growth and socio-economic development, water consumption will increase substantially, and the contradiction between supply and demand of water resources will become more acute. It is predicted that the total water demand in 20 10 will be 698.8 billion cubic meters, in 2030 it will be 800 billion cubic meters, and in 2050 it will be at least 850 billion cubic meters, which will increase by 1995 respectively, so as to achieve a general balance between supply and demand of water resources in moderately dry years. It can be seen that the gap in water use is still quite large. Only by adhering to the principle of combining open source with throttling, putting throttling in the first place, further strengthening water conservation, realizing optimal allocation and efficient utilization of water resources centered on water conservation, and striving to achieve a basic balance between supply and demand, can the long-term economic development goal be successfully achieved. Saving water and ensuring the sustainable utilization of water resources are our common cause and our common responsibility!