Introduction
China's Honghu, Poyang Lake, Dongting Lake, Dianchi and other lakes, since 1960, has been surrounded by large-scale reclamation, exacerbated the environmental ecology of the lake area. Honghu, Hubei Province, has a still 832,000 mu of waterfield in 1964. It has reached 300,000 mu, and there are 530,000 mu of water. Due to the low reduction of the lake, severely weakened the residual disaster relief function of the lake area, in the abundance of the floods, the soil environment of low lake field has deteriorated, and the benefits decreased.
Junction enables the rivers and lakes, swimming, half-swaying fish, destroying the ecological conditions of breeding, fertilization, so that the aquatic resources of the lake are greatly damaged. Western Lake Field must adopt a comprehensive survey to ensure the coordination of lake ecology, play a variety of functions such as lake, aquatic, agriculture and tourism to obtain comprehensive benefits of ecological, environmental and economy.
Disadvantages
Perhe Lake to set the field, it is a matter of "ancient existing" in Chinese history. Since the Spring and Autumn Warring States, the rulers of the past, in order to alleviate the pressure of population, they promote the field, and the water. There is also a fresh snail shell in the soil.
After 1949, after the founding of the People's Republic of China, the CPC Mao Zedong proposed "Great Leap Forward" in 1958, and Hunan Province has entered a peak period in the field of Lake Dongting Lake. A large number of peasants moved to Dongting Lake District, surrounded by Lake, established many dams, surrounded by Dongting Lake, so that the "eight hundred miles" in history became "three hundred miles".
In 1998, after China has experienced a big flood, the Chinese government realized the harm of the lake to the field, and made a significant decision-making in the Yangtze River in the middle and lower reaches of the Yangtze River. This is China since the Spring and Autumn Warring States Warring States, the first time from the surrounding lake, consciously turned into a large-scale retreat, giving the flood. In 1998, Hunan Province began implementing the "4350" project (ie 4350 square kilometers in 1949), about 600 kilometers of farmland was "double back", that is, residents completely moved away, the dam was discarded; or "single Retreat, that is, the resident still stays in the country, flood in the flood season, and farming the field.
Western Lake is first to accelerate the process of lake swamp, the lake area continues to shrink, resulting in growing by water and drought disaster, followed by water-vivid plant resources, the ecological environment of the lake area is inferior, so that fish The species continues to decline, and the quantity is reduced.
Hazard
Over-reclamation tends to damage the natural resources of lakes, destroy lake ecological environment and storage.
my country's Honghu, Poyang Lake, Dongting Lake, Dianchi and other lakes have been surrounded by large-scale reclamation since the 1960s, exacerbated the environmental ecology of the lake area. Honghu, Hubei Province, has a still 832,000 mu of waterfield in 1964. It has reached 300,000 mu, and there are 530,000 mu of water. Due to the low reduction of the lake, severely weakened the residual disaster relief function of the lake area, in the abundance of the floods, the soil environment of low lake field has deteriorated, and the benefits decreased. Enclamation makes the water birds to live in a big reed, and the environment is destroyed, so that the water is vivid, the plant species changes, and some populations have almost extracted, and the rivers are separated, swaying, and half-swaying fish. The ecological conditions of breeding, fertilizer, so that the aquatic resources in the lake are greatly damaged. Western Lake Field must adopt a comprehensive survey to ensure the coordination of lake ecology, play a variety of functions such as lake, aquatic, agriculture and tourism to obtain comprehensive benefits of ecological, environmental and economy.
A large number of periopalands are prone to flood disasters. The Yangtze River Basin is an example. After the liberation, a large number of surrounding lakes in the middle of the Yangtze River, Dongting Lake is rapidly declined by the original largest freshwater lake. The area of other freshwater lakes is also reduced rapidly, and some even completely disappear. These lakes play a role in the water conservancy, and the reduction in the lake area, directly leading to the long-range spatial shunt, which is easy to cause floods. The floods in 1998 also have a relationship with this.
Since the 1950s, my country's lake has decreased rapidly, only 543 lakes with only 1 square kilometers or more. According to the lake data in Hunan, Hubei, Jiangxi, Anhui and Jiangsu, in the middle downstream of the Yangtze River, the original lake area of 29,000 square kilometers, in the 1980s, the area is only 1.9 10,000 square kilometers, died of more than 10,000 square kilometers of lake area, and there was a "province of thousands of lakes", Hubei Province, there were 1066 lakes in the 1950s, with only 309 lakes left. In the Jiangsu Province, there is a lot of water networks in Jiangsu Province, and there are many lakes, since 1957, there have been more than 1,500 square kilometers of lakes cut by the surrounding Lake, and there are more than 40 dying lakes.
Since the late 1950s, many areas of my country have enveloped lakes and the booming of the risks. According to statistics, there is at least 1 million hectares of lakes in the country, and the loss of freshwater resource adjustment is 35 billion cubic meters. In recent years, with the development of economic construction, the water volume of the basin has increased, the water volume is reduced, the water level is not enough, the water level is decreased, the area is reduced, causing some lakes to disappear, some large lake area is also reduced.
The Feihu, which is the first to speed up the lake's maze, so that the area of lake is constantly narrowing, and the surface runoff is difficult, resulting in frequent drought and flood disasters. Such as: due to the continuous decrease in lake, lake after shrinking has basically lost its original stock, resulting in a year-on-year growth trend, an average annual growth trend, an average of more than 460 hectares in the 1950s, an increase of more than 170 in the 1980s 10,000 hectares and eight years since the 1990s, except in 1993, there is a great level in the 80s. Secondly, the water-vivid plant resource decline, the ecological environment of the lake area is inferior, and the species of water vivid plants will decrease, and the quantity is reduced.
Status
Perhe Lake Flat Resistance Yangtze River "Cai Jing" "I plant me Tian, what is the relationship with the flood in the Yangtze River? "Recently, a fisherman was interviewed in the suburbs of Jiangxi, and a fisherman was interviewed. When the reporter asked if there was an ecological adjustment function of the lakeside, he suddenly became I can't understand it very well.
is true, but in fact, this is the phenomenon of surrounding Lake that is ignored by many people. When the villager harvested rice in the field, when the fish group was raised in his own fish pond, no one would think that before they settled, they were part of Poyang Lake. When the tide, this should be It is a region that adjusts the water level of the lake.
"said that this is a reverse and natural behavior, which exertys to the Yangtze River in the middle and lower reaches of the Yangtze River." For the raising phenomenon of the lake, it has been engaged in extreme climate disaster assessment and sustainable development for many years. The Professor of Nanjing Information Engineering believes that this human behavior that ignores the natural environment is now producing "anti-anti-" consequences.
It is understood that if the Yangtze River is metaphor into a blood, then Poyang Lake is its branch, and in the vicinity of Poyang Lake, the large and small "micro lake" originally formed in the natural environment is "" Capillary. These blood vessels may not be eye-moving, but because they maintain a connection with the Yangtze River, when they are less than less, people can get the lotion of water, and when precipitation is more, they will become the "reservoir" of the Yangtze River level. ".
can be problematic, now these "capillary" is not filled into fertile land, that is, it is circled into a fish pond. After being cut off, the water in the Yangtze River and Poyang Lake could not find a place to evacuate, and finally it can only be forced to the ground.
Greenhouse gas affects Earth's rainfall mode
However, if you use the depth of the Lake, you can explain that the Yangtze River is easy to flood, then there is a problem. No solution, where did these suddenly increased water? "According to the observation, in May this year, when my country's Jiangnan, South China was frequently attacked by heavy rains. It is an abnormal gas circulation. The high pressure of South Asia has a strong part of the year, which has prompted the subtropical high pressure to stably maintain in a part of the South, in which case The South Rain Belt will become very stable. "Experts from the Chinese Meteorological Bureau Wuhan Rainstorm Research Institute told reporters that the rain belt maintains a steady state, on the other hand, the active South Disshanti and subtropical high pressure Impact, the southern region not only ushered in the southwest warm moisture stream of Bangladesh, and also encountered another warm moisture stream from the South China Sea and the Northwest Pacific, and there were many factors, causing heavy rain.
Why does this abnormally atmospheric circulation appear? Why have so many water cavas simultaneously gathered to my country? For these unin-explanatory abnormalities, experts believe that should be understood to the global climate. "The IPCC (United Nations Intergovernmental Change Special Committee) has been very clear. In the past 100 years, global climate change is very obvious, including the fact that 'warming' is particularly obvious, and the cause of this result is currently It is the frequent activity of humanity to emit a large amount of greenhouse gas. "Professor Wenjin said that due to the increase in greenhouse gases, the change in water vapor transport chain has made some areas more likely to have flood disasters than ever, while others The area will be more easily drought than before.
This is also explained to some extent, why there is a drought in the southwest my country in the spring, and now there is a situation in the southern region.
Urbanization or enhance the chance of rainfall disaster
The disaster is ruthless, and now flooding is farmland, will it be turned to the city next time? This is not worried.
The reporter learned that the urbanization process is a double-edged sword. He also gives people convenience, while having a good life, it also changes the nature. A statistics show that in addition to the lake sharp reduction, in the past 40 years, due to various reasons, my country has formed a peak of deforestation. According to estimates, 100,000 acres of forest storage is equivalent to a reservoir of 2 million cubic meters of a library, and the forest is still can't be water in the mountain after heavy rain, increasing the frequency of flood.
At the same time, after the urban construction area is expanded, the reinforced cement covers the surface of the soil, making the impervious ground increase, and the flow rate of the surface is accelerated after heavy rain, and the flood flow volume is doubled. "There is also a city's 'Trend Island Effect' and 'Yuao Effects', which will cause urban airflow uncomfortable, increased gas bodies, etc., people feel that there is frequent strong convection, thunderstorm weather, etc." Professor Wenjin said The trend of urbanization is difficult to change, which means that the chance of disasters in the future city will gradually increase.
However, it is desirable to still exist. "While maintaining urban development, we must find ways to change people's consumption habits, change the industrial structure of the city, 'low-carbon economy' is a good way." Experts believe.
change, engraved, control of high-energy-consuming industries such as oil, steel, cement, while using renewable energy to reduce greenhouse gas emissions as much as possible. The expert's point of view is that this initiative is unable to directly reduce the flooding of flooding, but can indirectly affect the global air environment, so that the water vapor distribution will go back to the right track.