Chapter 15 4. China's water crisis

By the year 2000, my country's grain output should be stable at more than 50,000 tons.What are the biggest constraints to achieving this goal? Liu Jiang, the former Minister of Agriculture, said: "It's water." Here's another factor we've overlooked: How can water be a constraint on food production? After reading this section, you will know how the shortage of water resources and frequent floods have seriously affected China's food development. Water is the source of life.Without water, there would be no human beings, no living things, just like other planets in the vast universe.

The reason why the earth is a living star is that it has water.In the universe, the earth is actually a "water ball", because 70.8% of the earth's surface is covered by water. However, although more than 70% of the earth's surface is water, the global freshwater resources only account for 2.53% of the total water storage, about 350 million cubic meters, and most of these fresh water are polar ice sheets, which are difficult for humans to use. Ice from alpine glaciers and frozen terrain.The rivers, lakes and groundwater that humans can really use only account for 0.34% of the global freshwater resources, about 105 trillion cubic meters.

This means that, like oil, water is neither inexhaustible nor inexhaustible.If you use more, it will be less, and if you use more now, it may be less in the future.According to scientists' calculations, the world's fresh water consumption is currently 4.13 trillion cubic meters per year. With the continuous growth of the world population, it is estimated that it will increase to 7 trillion cubic meters by the year 2000.Obviously, how nervous this is compared to the total freshwater reserves of 105 trillion cubic meters. Therefore, as early as March 1977, the United Nations Conference on the Human Environment issued a warning to the whole world: following the oil crisis, mankind will face a water crisis.

In fact, many countries and regions have already felt the crisis of water shortage.According to the latest report released by the relevant agencies of the United Nations, more than 80 countries in the world, which account for 40% of the population, are facing the crisis of water shortage. Among them is China! China has 20 rivers with a length of more than 1,000 kilometers, more than 2,600 lakes, and tens of thousands of reservoirs, with a total water resource of 280 million cubic meters, ranking sixth in the world after Brazil, the former Soviet Union, Canada, the United States, and Indonesia. bit.But we have a population of more than 1.2 billion. Calculated on a per capita basis, the per capita occupancy is 2,400 cubic meters, ranking ninth in the world, and less than a quarter of the world per capita level of 12,000 cubic meters.In some places, the per capita occupancy is lower. For example, the per capita occupancy in Beijing is only about 15% of the world's per capita occupancy.

The Creator is unfair to China in the distribution of water resources, and God is not "friendly" to China in terms of precipitation.The world's average annual precipitation depth is 800 millimeters, and the precipitation is uniform.However, the annual precipitation in China is only 630 millimeters deep, and most of it is concentrated in the four months of the flood season. Not only can it not be stored and utilized, but it becomes floods everywhere.As a result, there are frequent torrential rains and floods in the south, and there are floods in nine out of ten years; in the north, there is no rain and severe drought, and nine out of ten years are drought years, of which four or five are severe drought years.

Therefore, China is listed as one of the 13 water-poor countries in the world. In 1979, 154 cities in China were short of water. Up to now, more than 300 cities in more than 600 cities across the country are short of water, of which 108 are seriously short of water. In addition to urban water shortages, agricultural water shortages are even more serious.It is estimated that my country's agricultural water shortage reaches 30 billion cubic meters per year, accounting for 30% of agricultural demand. 80 million rural people have difficulty drinking water, and 300 million mu of farmland suffers from drought.Our arable land averages 1,700 cubic meters of irrigation water per mu, while the world average is 2,300 cubic meters.By 2000, my country's water shortage will reach 100 billion cubic meters.Of the 700 million mu of irrigated land across the country, 40% are not moderately irrigated.Due to the drought, an average of 300 million mu of grain fields across the country are affected every year, and an average of 18.9 billion kilograms of grain is lost each year, which is equivalent to the grain output of two Shanxi provinces.The per capita water resources in Hebei Province are only 1/26 of the country's, which is lower than that of the severely arid Arabian Peninsula.

According to agricultural experts, 80% of my country's grain, 90% of cotton, and 95% of vegetable production depend on agricultural irrigation.However, my country is precisely a country that is extremely short of water resources.Even with this limited water resource, its distribution is very unsatisfactory, and it is extremely uncoordinated with my country's arable land and population distribution.The cultivated land north of the Yangtze River accounts for 64% of the country's cultivated land, while aboveground water resources account for only 17%. Among them, the cultivated land in the Huanghuaihai region, which has the greatest potential for increasing grain production, accounts for 42% of the country's cultivated land, while the aboveground water resources account for less than 6% of the country's total.

Due to the severe shortage of water resources, most parts of China are in a state of drought.According to the statistics of disasters in the 46 years after liberation, among the natural disasters in our country, drought has a great impact on our country's agricultural output.In the 1990s, the annual drought-affected area was about 400 million mu, more than double that of the 1950s, and the disaster-affected area tripled.The drought from 1990 to 1994 alone reduced my country's grain production by more than 3.5 million tons. On the one hand, my country's water resources are seriously scarce, on the other hand, very limited water resources are still seriously polluted, and the water quality is constantly deteriorating.According to a survey of 53,000 kilometers of river sections across the country, about 25.3% of river water cannot be used for irrigation due to pollution, and only 14.1% meet drinking water and fishery water standards.

There is no doubt that the shortage of water resources will become a major factor hindering the development of my country's food production.If we don't do a good job in the development and utilization of water resources from now on, the phenomenon that the shortage of water resources will affect food production and then affect our hunger may happen at any time. On June 3, 1998, at the meeting of academicians of the Chinese Academy of Sciences, academician Xu Guanhua, director of the Department of Earth Sciences of the Chinese Academy of Sciences and vice minister of the Ministry of Science and Technology, announced the report "The Way Out of China's Water Problems" submitted by the Chinese Academy of Sciences to the State Council.The opening sentence of this report is: "The water problem will become the most prominent problem of my country's economic development in the 21st century."

A month before this, Mr. Lester R. Brown, who has been expressing concern about China's food problems, also held a press conference in Washington, and distributed their report "China's Water Scarcity Shakes World Food Security".The first sentence of the report reads: "The unexpectedly sharp decline in China's agricultural water supply poses a threat to world food security." Leaving aside Brown's sensational "threat theory", we find that both reports objectively pointed out the impact of China's water shortage on food production.The report of the Chinese Academy of Sciences pointed out that among the 700 million mu of effective irrigated area in China, about 100 million mu is due to insufficient irrigation water, which affects grain production by at least 300-400 kg. It is to ensure the amount of irrigation water.Brown pointed out that 70% of China's food supply comes from irrigated agriculture, but due to three reasons, the current amount of irrigation water will decrease day by day: first, a large amount of surface water is transferred from rivers and reservoirs to cities; second, groundwater is over-exploited; The third is water pollution caused by high speed.

So, in the face of increasingly severe water shortages, can the Chinese just sit back and wait?actually not.Although with the increase of population and the acceleration of industrialization, the contradiction of the lack of water resources in our country will be further intensified, but as long as we attach great importance to water issues from now on, study water issues seriously, and adopt a series of effective Not only will water not become an obstacle affecting my country's grain production, but it may also become one of the basic conditions for ensuring grain production. Academicians of the Chinese Academy of Sciences believe that there are only two ways to solve China's water crisis, one is to increase revenue, and the other is to reduce expenditure.And the most important and fundamental thing is throttling.Academician Xu Guanhua believes: "The only way to alleviate the contradiction between supply and demand of water resources is to save and use water resources in all aspects of agriculture, industry, mining, cities and life, to maximize the benefits and potential of limited water resources, and to develop the economy while developing the economy. Gradually reduce water consumption." According to the report of the Chinese Academy of Sciences, according to international experience, the total water consumption and per capita water consumption in the United States have been decreasing year by year since the 1980s. In Japan, which has experienced the fastest economic development since the 1960s, industrial water use in the late 1970s and agricultural water use in the early 1980s reached zero and negative growth respectively.These international experiments can be used as a reference for our country.Judging from the current situation of water use in the country, there is still great potential for water saving.In agriculture, as long as the traditional flood irrigation is changed to small furrow or furrow segmental irrigation, this measure alone can save 20-25% of water.The potential for industrial water saving is even greater. Many industrial enterprises in my country now have backward production processes and consume a lot of water. If advanced water saving processes are generally adopted, about 15 billion cubic meters of water can be saved each year.The waste of urban domestic water is also quite serious. If water-saving measures are taken, 1/3 to 1/2 of water can be saved. Academician Xu Guanhua said: "As a measure to alleviate the contradiction of water shortage, saving water is by no means an expedient measure, but is related to the fundamental plan for the sustainable development of China's society and economy. A water-saving society should be the goal of struggle, and water conservation should be regarded as a goal. national policy." Brown suggested: "To solve the water problem, China must comprehensively adjust its agricultural, energy and industrial structures to achieve efficient water use while reducing water pollution." He also suggested that China save agricultural resources by planting low-water-consuming crops. use water. In addition to saving water, another very important aspect is water management.China has formulated a series of laws and regulations to protect water resources. The key now is how to implement them and manage water according to law. Water management, first of all, is to prevent and control water pollution. It must follow the provisions of the "Water Law" and "Environmental Protection Law". Whoever pollutes will take care of it. Newly opened factories that do not complete the sewage treatment facilities at the same time must not be put into operation. Big polluters must be resolutely ordered Shutdown management.The second is to rationally develop and use water resources.Implement a system of unified planning, both storage and discharge, pollution prevention and centralized management, rational development, appropriate allocation, and paid use. For the survival and development of the Chinese nation, we must protect our water resources like we protect cultivated land, because it is also our lifeblood. The great river goes from east to west, forever. If you ask what is flowing in a river, a 3-year-old child will know that it is water. In fact, the standard answer should be: one part is water and the other part is soil. Here's another thing that bothers us: soil erosion. The entire terrain of China is high in the west and low in the east, with an average altitude of 1,525 meters and a large gravity gradient, which itself is a situation of soil erosion.In addition, a large number of commercial forests and vegetation have been cut down, making China's soil erosion more and more serious.According to estimates by experts, in my country's existing cultivated land area, the area of ​​soil erosion has reached 500 million mu, involving more than 1,000 counties.Among them, the most serious soil erosion and the largest area are the Loess Plateau, followed by the southern hilly area, the rocky mountainous area in North China, and the black soil area in Northeast China. The total amount of surface soil and sediment flowing into rivers in our country reaches 105 billion tons every year, of which more than 5 billion tons of top soil is equivalent to scraping a few centimeters of fertile soil from the surface of the country's cultivated land; the loss of nitrogen, phosphorus, and potassium fertilizers is about 40 million tons. tons, which is equivalent to the total output of 100 chemical fertilizer plants with an annual output of 400,000 tons.Due to water and soil erosion, the cultivated land in mountains and hills has been washed away, the fertile fields in rivers and roads have been scoured, a large number of soil layers have become thinner, the land has been compacted, soil colloids have been destroyed, and land fertility has declined. Due to our destruction of vegetation, there is serious soil erosion in almost all river basins from south to north across the country.Looking at the rivers and rivers in China, not only the Yellow River is full of yellow water, but the Yangtze River is also muddy and yellow. The Pearl River is flooded, and the Heilongjiang River is black. The upper reaches of the Pearl River have been deforested for many years, and trees as thick as bowls have become rare. As a result, the rivers are filled with mud and sand, and the reservoirs are seriously silted up. The Pearl River has become a veritable "Zhu (iron red) river". The sediment brought by the Yangtze River into the East China Sea amounts to 500 million tons per year, and the amount of sediment transported has reached 1/3 of that of the Yellow River.It is equivalent to the total amount of sediment transported by the Nile, Amazon, and Mississippi rivers. The annual sediment load of the Yellow River is as high as 1.6 billion tons, and the total area of ​​soil erosion in the Loess Plateau is 540,000 square kilometers, accounting for 90% of the total area of ​​soil erosion in the Yellow River Basin. Many scholars call soil erosion "arterial bleeding".And China is currently bleeding all over: the south is bleeding, and the north is also bleeding. Scientists estimate that 10,000 tons of fertile soil can only cover 1 acre of land with a thickness of 7 inches.It takes Nature from two hundred to a thousand years to cover an acre with an inch of fertile soil. What a arduous project this is! However, the loss of water and soil has not stopped because of the hardships of natural cultivation, and the bleeding of the land continues.And the ground that continues to bleed must grow weaker, paler and older. Soil erosion first brings about a rapid decline in soil organic matter. The cultivated land with serious loss is exposed to sand and rocks, and the grain output decreases year by year. In severe cases, the grains will not be harvested. The decline in soil quality has directly affected the substantial reduction in biomass, resulting in serious shortages of food, feed, fuel, and fertilizers.The decline of total biomass has a direct impact on people's lives.In order to make ends meet, they continue to cultivate and deforestation indiscriminately, resulting in greater soil erosion, a greater decline in biomass, greater living difficulties, and greater ecological environment damage, which is another new wave of soil erosion start…… The most direct relationship with water and soil loss is the flood disaster that makes us tremble with fear and make us sleepless. In 1998, a painful memory was forever left in the minds of Chinese people.In the summer of this year, China suffered a rare flood in the world. Although tens of millions of parties, governments, soldiers and civilians fought bravely, they still suffered heavy losses.More than 240 million people in 28 provinces, municipalities and autonomous regions across the country were affected to varying degrees, more than 17 million houses collapsed and damaged, more than 21.5 million hectares of crops were affected, and direct economic losses exceeded 200 billion yuan. The worst loss was in the Yangtze River Basin.The Yangtze River is the third largest river in the world. Its annual water flow to the sea is about 100 million cubic meters, accounting for more than 1/3 of the country's river inflow and feeding more than 1/3 of China's population. It is called the mother river of the Chinese people.At the same time, this is also a dangerous river that makes hundreds of millions of Chinese people terrified. Every summer and autumn, it floods and endangers life. Now, floods in the main stream of the Yangtze River are becoming more frequent and more serious.According to statistics, the Yangtze River flooded every 18 years in the Tang Dynasty, every 6 years in the Song and Yuan Dynasties, and every 4 years in the Ming and Qing Dynasties. In the 18 years from 1931 to 1949, the Jianghan Plain suffered from floods in 16 years.In this century, there have been more than ten catastrophic floods on the Yangtze River.Famous ones include: the flood of the Yangtze River in 1905, the disaster occurred in Sichuan, "the wealth and goods of the merchants and people were drifting away", and the flood of the Minjiang River in 1919 flooded the whole city of Leshan, and the water in Jiajiang City was 5 to 6 feet high. , Died in nine out of ten floods; in July 1926, a flood occurred in Hunan, and more than 40 counties were affected. The flood of the whole river flooded more than 56 million mu of farmland, 28 million victims, and 145,000 deaths. The entire Hankou, half of Wuchang and part of Hanyang were all immersed in the water from several feet to more than Zhang, and the deepest reached 278. ruler. In 1935, the Yangtze River Basin experienced the largest rainstorm on record. Since July, the Yangtze River and the Yellow River flooded simultaneously, flooding 16.06 million mu of farmland, causing more than 24.4 million victims and nearly 200,000 deaths. In June 1949, the middle and lower reaches of the Yangtze River were flooded, and 57,000 people died in Hunan Province alone; in July 1954, the Yangtze River encountered a large-scale flood that was rare in a century, with a total area of ​​54 million mu and 18.88 million victims. Traffic could not be opened normally, and the epidemic alone claimed 30,000 lives; in July 1969, floods in the middle and lower reaches of the Yangtze River caused serious disasters in Hubei and Anhui, 83 counties and cities were affected, and 1,603 people died; 138 counties and cities in the province were affected, 57 counties were flooded, and 1,358 people died. Chinese people who pay attention to the weather will find that around winter, the north wind continues to control the north and invade the south, bringing sunny, cold and dry; while around summer, the south wind keeps covering the south and often advances to the north, bringing Wet and rainy.Therefore, the annual precipitation in most parts of China is concentrated in the months before and after summer. The north has spring drought almost every year. From late spring to late autumn, China has experienced the test of rainy weather in sequence from south to north. Therefore, it can be said that In my country, there is almost no overall good weather in our country, and there are more or less floods and droughts in different degrees every year.According to statistics, among various agricultural seasonal disasters, drought and flood disasters account for about 83% of the total disaster-affected area. China's topography also exacerbates floods and droughts brought about by the monsoon climate.Anyone with a little knowledge of geography knows that China has a cascading distribution of highs in the west and lows in the east, and most of the big rivers are formed in the western plateau and flow into the sea in the east.Once large-scale rainfall occurs, the rainwater from the high places in the upper and middle reaches will quickly press down to the lower reaches, and the lower reaches are mostly economically developed cities and densely populated plains.The water flow in the plain area is relatively slow, and it is easy to be flooded and difficult to discharge, which has caused major floods again and again. However, the frequent floods in China cannot be entirely blamed on God and nature, because in addition to heavy rains, it is also closely related to the decline of the natural ecological functions of rivers and lakes.The middle and lower reaches of the Yangtze River once concentrated the largest group of freshwater lakes in my country.These beautiful lakes accommodate hundreds of rivers and regulate flood peaks, forming a harmonious whole with the Yangtze River.However, soil erosion and land reclamation make these lakes bear the brunt, shrinking day by day.The lakes in the middle and lower reaches of the Yangtze River that were once scattered like pearls and jade have lost their charming luster and disappeared from the land of China one after another. The area of ​​lakes in the middle and lower reaches of the Yangtze River was still more than 22,000 square kilometers in the 1950s, but only 12,000 square kilometers remained in the 1980s, a decrease of 45.5%.Dongting Lake, known as "spanning eight hundred miles", covers an area of ​​1.3 million square kilometers. It swallows the Yangtze River and embraces the waters of Yuanli and Lili in Hunan. It is like a large natural reservoir and plays an important role in flood storage. It not only maintains thousands of lakes in the lake area. The safety of tens of thousands of people, and nourished tens of thousands of hectares of fertile land.However, for nearly half a century, Dongting Lake has become like an overtired and overworked giant, and its face has become increasingly haggard. In 1825, the area of ​​Dongting Lake reached 6,270 square kilometers. Later, it was divided into East, West and South Dongting Lakes by sandbars. The area was greatly reduced by extensive reclamation. Today, only less than 3,000 square kilometers are left. The volume of the lake has increased from 29.3 billion cubic meters in 1949. meters, reduced to the current 17.8 billion cubic meters, which has been reduced by nearly half in 40 years.The ecological function of natural lakes is to regulate and store floods and reduce the flood peak of rivers.The shrinking of the lake area will inevitably cause the water level of the lake to rise and the flow out of the lake to increase, which will inevitably increase the pressure on other flood control facilities such as reservoirs, dams, and flood diversion and detention areas.Hubei is known as the "Province of Thousands of Lakes". In the early days of the founding of the People's Republic of China, there were 1,066 lakes, but now only 309 remain. It is difficult to avoid. Ecological damage and soil erosion lead to sediment deposition, which is a very important reason for the reduction of the lake area.Just taking the Yangtze River as an example, the ecological balance has been severely damaged in the past 100 years, which has caused two fatal problems in the Yangtze River Basin: one is the possibility of floods caused by heavy rains greatly increased, and the other is flood control and disaster reduction when floods occur. ability is greatly reduced. According to survey statistics in 1957, the forest coverage rate in the Yangtze River Basin was 22%, and the area of ​​soil erosion was 363,800 square kilometers, accounting for 20.2% of the total area of ​​the basin. However, only 30 years later, by 1986, the forest coverage rate had been reduced by more than half. With only 10% remaining, the area of ​​soil erosion has doubled to 739,400 square kilometers, accounting for 41% of the total area of ​​the basin. The upper reaches of the Yangtze River is the second largest forest area in my country after the Northeast, but only cutting but not planting has caused a sharp decline in the forest area.For many years, the ratio of forest harvesting and regeneration in Sichuan was only 11:1. The forest coverage rate of the whole province in the Yuan Dynasty was as high as 50%, and it was still 20% at the beginning of liberation, but only 12% in the early 1980s.Without exception, Yunnan, Anhui, and Jiangsu have reduced their forest coverage by half in the past 30 years. The areas of soil erosion in Hubei and Hunan accounted for 30% and 28% of the total area of ​​the province respectively. In the 1950s, the area of ​​soil erosion in Jiangxi Province It is still 4% of the province's area. By the 1980s, this figure had become 23%. In the 12th century, the forest coverage rate in Hunan was about 70%, and in 1967 it was only 34%. According to experiments by scientists, a 25-year-old natural tree can absorb 150 millimeters of precipitation per hour, and a 22-year-old artificial water source forest can absorb 300 millimeters of water per hour.And naked to absorb only 5 mm per hour.65% of the precipitation in the forest land is intercepted or evaporated by the forest canopy, 35% becomes groundwater, and about 55% of the precipitation on the bare ground becomes surface water loss, 40% is temporarily retained or evaporated, and only 5% infiltrates the soil.The water conservation capacity of forest land is 7 times higher than that of bare land.According to expert calculations, a forest with an area of ​​100,000 mu is equivalent to a reservoir of 2 million cubic meters.Indiscriminate deforestation has resulted in sparse grass and trees, reduced the ability to store water in the mountains after heavy rains, aggravated the onset of flood peaks, increased the frequency of disasters, and also aggravated soil erosion, resulting in river silting and river bed elevation. It is higher than the farmland, the flood discharge function declines, and the waterlogging of the lakeside causes disasters.The area of ​​water and soil erosion in the Yangtze River Basin has increased from 360,000 square kilometers in the 1950s to 560,000 square kilometers now, and the total annual soil erosion is as high as 2.24 billion tons.Over the past 30 years, Dongting Lake has accumulated a total of 4 billion cubic meters of sediment. The riverbed at the bottom of the lake has been silted up by an average of 1 meter, and the maximum local silt height has reached 12 meters. In the face of the raging flood, can we still blame God blindly? If we don't learn our lesson and continue to deforestation, maybe the next round of floods will be bigger and the losses will be more next time.In order for us to have a stable home and a peaceful land, we must treat nature well. There is such a story in "Bible Genesis". According to God's will, Noah and his three sons built an ark with Gope wood... There was a torrential rain in the sky, and the flood flooded the entire earth. Only Noah's The ark carried his family, children and animals, floating on the boundless water surface... Facing the rolling flood, we can't help but ask, where is our Noah's Ark? China has a tradition of water control since ancient times, and water control has become a major event in the governance of Anbang in the past dynasties.After liberation, the Party Central Committee and the State Council attached great importance to water conservancy construction, and listed the management of large rivers as a top priority, and initially established a relatively complete flood control system. Since the 1950s, my country has focused on flood control, and has generally compiled river basin plans for major rivers, making flood control based on a more scientific basis. For more than 40 years, due to the construction of a large number of water conservancy projects, the flood of rivers at all levels has been greatly affected. With varying degrees of control and regulation, it can be said that our flood control work has achieved great achievements that have attracted worldwide attention. At present, my country has initially established a flood control system including many measures. This system protects 500 million people, more than 30 million hectares of arable land and accounts for 2/3 of the country's industrial and agricultural output value. It is precisely because of this system that reform and opening up Only then can it be carried out smoothly, and the national economy can develop rapidly.After the founding of New China, we mobilized the power of the whole country to comprehensively control the Yellow River, basically controlling the flooding of the Yellow River, and turning this harmful river that endangered hundreds of millions of people into a beneficial river that nourished the people of the Central Plains. In the past 50 years since the founding of the People's Republic of China, compared with the previous 50 years, China's ability to resist disasters has improved surprisingly. In 1931, there was a flood in the middle and lower reaches of the Yangtze River, and all the big cities became flooded for a while. In 1935, there was another flood in the Yangtze River, and Wuhan was flooded for the second time. This year, Wuhan faced a flood level higher than that in 1935, but it was safe and sound. In 1938, the Yellow River burst, killing 890,000 people. Although the Yellow River was flooded in 1958, the embankment of the Yellow River remained unmoved, and it remained peaceful for the next 40 years. In 1931, the Huaihe River flooded 75,000 people, and in 1991 the Huaihe River flooded, and the death toll was reduced to about 1,000. The Yangtze River flood in 1998 was the same as that in 1931 and 1954, and it was a major flood in the whole basin, but the losses were much smaller than those in 1931 and 1954. In 1931, more than 300 main dikes burst, and almost all of the middle and lower reaches of the Yangtze River were affected; in 1954, more than 60 main dikes burst, diverting 102.3 billion cubic meters of flood water, and the Jianghan Plain and Yueyang, Huangshi, Jiujiang, Anqing, Wuhu and other cities were flooded. In 2009, only one breach of the main embankment of the Yangtze River, the Jiujiang embankment, was successfully blocked within a few days, and the cities along the river and the main traffic lines were not flooded.In the Yangtze River Basin, 145,000 people died in floods in 1931, 33,000 people died in 1954, and only 1,320 people died in 1998. However, the standards for flood control and waterlogging control of major rivers in my country are not high. The flood control standard for the middle and lower reaches of the Yangtze River is about once in 10 to 20 years. Next, the flood control capacity of many cities is not high, and some are not fortified, so that we have to repeatedly emphasize the prevention of major floods and disasters every year. Now, under the unified deployment of the Party Central Committee and the State Council, a mass movement to promote water conservancy has begun.At present, a number of flood control and conservancy projects are under active construction or preparation.For example, after the completion of the Xiaolangdi Water Conservancy Project, the flood control standard of the lower reaches of the Yellow River will be raised from the current 60-year occurrence to the 1,000-year occurrence; after the completion of the Huaihe River Control Project, the flood control standard of the middle and lower reaches of the Huaihe River will be raised to a 40-year occurrence. Once in 100 years; after the completion of the 10 key projects to control Taihu Lake, the flood control standard can reach once in 50 years... The most encouraging thing is that after the completion of the Three Gorges Project, the Yangtze River Basin will greatly reduce the incidence and loss of flood disasters degree. At the same time, strengthening ecological protection and reducing soil erosion has become a central content of flood prevention and control.Now, the shelterbelt system project in the middle and upper reaches of the Yangtze River has been fully launched.Recently, Premier Zhu Rongji of the State Council clearly instructed that the trees in the middle and upper reaches of the Yangtze River have been cut down, causing serious soil erosion and turning many reservoirs into sandbanks.Therefore, not a single tree should be cut down.According to Premier Zhu's instructions, from September 1, 1998, all mountains in Sichuan were closed, and no tree in the Yangtze River Basin was allowed to be cut down.While banning logging, vigorously plant trees and afforestation.The area to be greened in the upper and middle reaches of the Yangtze River is 600,000 square kilometers. The state will invest 15 billion yuan to make it all green in a certain period of time, so as to increase the water storage capacity by hundreds to hundreds of billions of cubic meters.It seems to have no immediate utility, but it is the limiting factor for restoring the virtuous circulation system of the Yangtze River.Only when the forest coverage rate in the upper reaches of the Yangtze River reaches more than 50% and the water source is conserved to 500 billion cubic meters, can the entire Yangtze River be beautiful and the water volume stable. In a sense, the history of thousands of years of human civilization is also a history of the evolution of forest destruction-recognition-re-destruction-re-recognition.Whether East or West, without exception.Ancient Babylon, ancient Egypt, and ancient Indian civilization all declined with the disappearance of forests. When Columbus landed on Haiti in the northern Caribbean island 500 years ago, he praised: "This is the most beautiful place in the world." However, after hundreds of years of colonial rule, 98% of the forests have disappeared, and the former paradise on earth has become a desert. .Korea has historically been rich in forest resources.Due to repeated wars, especially the 35-year colonial rule, the destruction of forest resources has exacerbated the flood disaster in the Han River Basin. Since 1973, South Korea has implemented two ten-year plans of “Mountain Control and Greening” with remarkable results. In 1988, the "Mountain Forest Recycling Plan" focused on improving forest quality and environmental benefits began to be implemented.In Japan's long-term practice of controlling mountains and rivers, it has left behind the famous saying that "those who cannot manage mountains cannot govern the country". In France and Germany in the first half of the 18th century, deforestation was very serious, often followed by floods and droughts.After experiencing floods and droughts, they began to pay attention to afforestation and closed mountains for afforestation. Now they have achieved obvious results, and the frequency of floods and droughts has dropped significantly. According to the research results of domestic and foreign scholars using modern value theory to evaluate forest ecological benefits in recent years, the ecological value of forests is equivalent to 10 to 20 times its economic value.At present, the annual water conservation capacity of China's forests is 347 billion tons, which is equivalent to 75% of the total capacity of the country's existing reservoirs (460 billion tons).This tells us clearly that to protect our homes from floods and our fertile fields from floods and droughts, the protection of forest resources is the key. The State Council has issued a forest logging ban. From now on, the middle and upper reaches of the Yangtze River and the Yellow River will completely stop logging natural forests, restore ecological vegetation, and reduce soil erosion. The State Forestry Administration has decided to stop reviewing and approving plans for comprehensive development and use of forest land, and to abolish documents related to compound forest management and mature forest land. In order for our homes not to be ravaged by floods, and for our lives and property not to be encroached by floods, it is our top priority to promote water conservancy construction and strengthen ecological protection. Let us use our hands to build a safe "Noah's Ark" for ourselves and our descendants!