Currently, more than 50 cities in China observed subsidence ground. The situation is compounded every year. It is predicted that in a few decades, some cities may disappear entirely. The main reason is the excessive use of groundwater.
According to a report in mid-March, the Ministry of Land and Natural Resources of the PRC, except for the major Chinese cities of Shanghai, ground subsidence is recorded in more than 50 cities. The total area of the surface subsidence of more than 200 mm is 79 thousand square meters. m situation is particularly serious in Beijing, Tianjin, Hangzhou and Xi'an.
Among the main reasons for this, apart from climate change and sea level rise, the Chinese experts call the excessive use of underground water, oil and natural gas.
Shanghai could become the second Atlantis
German radio Deutsche Welle in Chinese reported that on February 2 at Shanghai's Lujiazui area near the high-rise building under construction there was a crack in the ground about eight feet long. Specialists local geological institute studied the crack and came to the conclusion that it is the result of lowering the surface of the entire city, which occurs at a rate of an average of 7 mm per year in the whole city, and 12.56 mm per year in the area.
Chinese Journal "Tsaysin" reported that, since 1965, and in 2012, Shanghai sank into the ground at 110 mm, and for the last hundred years it was lower at 3,000 mm. In recent years, it is accelerating.
Many experts do not rule out that Shanghai could suffer the fate of the legendary Atlantis.
Lowered into the ground more than 50 Chinese cities
This quiet geological disaster gradually covers the entire country.
Tszochen Zhang, deputy head of the Chinese Institute of Geological and Environmental Monitoring, said the scope of the negative impact of subsidence is very extensive.
According to him, it is meant that the lowlands are elevated, resulting in urban drainage systems are deformed and do not work as well as significantly reduces the effectiveness of flood control systems. According to him, the uneven subsidence of the soil leads to the destruction of the foundations of buildings, damage to railways, bridges and water supply systems.
Go Cunha, director of the Research Institute of Nanjing Geology and Mineral Resources, for four years conducted research in this area, and concluded that if the land subsidence will occur at the same rate as it is now, in 2050 the sea surface rises to 400 — 700 mm, and the areas located in the Yangtze River Delta, completely submerged.
In the eastern city of Cangzhou, Hebei Province in the past 30 years, the earth's surface down to 2400 mm. This is one of the most affected by subsidence areas in China.
The city has an obstetrics and gynecology clinic. Originally it had three stories, but now there were only two ground, first floor was underground.
One reason for the subsidence is the excessive use of groundwater, resulting in north China have formed the world's largest underground funnel.
At one of these voids is Beijing, which is gradually sinking into the ground. Underneath the funnel occupies 2650 square meters. kilometers.
According to official figures, the city of Tianjin has dropped to 2000 mm, and the Tanggu District — at 3000 mm. To maintain the surface of the ground in the North China Plain on one level, it is necessary each year to fill this land with a total of 100,000 cubic meters.
Due to subsidence, roll famous Big Wild Goose Pagoda in the ancient capital city of Xi'an in China has exceeded one thousand millimeters.
Estimated government geological monitoring, only one Yangtze Delta region economic damage from subsidence in decades was about 315 billion yuan ($ 50 billion) in the North China Plain direct economic losses amounted to 40.442 billion yuan ($ 6.4 billion), while indirect losses reached 292.386 billion yuan ($ 46.3 billion).
The main reason for subsidence — the excessive use of groundwater
In addition to natural factors, lowering the ground in China, experts distinguish the most important reason — is the excessive use of groundwater.
In Shanghai, according to researchers from the Institute of Geological Survey, subsidence of 70% is for that reason.
According to official data of the Chinese authorities in the north of the country in excess of the safe for the ecological balance, annually consumed 120 billion cubic meters of underground water, which is 200 Bayyandyan lakes (the largest natural lake in northern China).
However, the researchers say, that the real situation is far worse to official statistics, and cost overruns of water in the area has reached 200 billion cubic meters. According to their estimates, to make up for these losses, naturally takes about 10,000 years.
Haihe River basin, and the other six largest rivers in China in recent years, water resources has declined significantly. Noticeable reduction in rainfall in these areas began in 1956. In the 90 years of flow of river water into the sea was reduced by 72% compared with the 50-ies. According to experts, it is directly related to the decline in groundwater.
Chinese environmental official website "Huantszin" reported that, since in recent years the amount of water in the Yellow River has been steadily declining in the province of Ningxia were dug more than 4 thousand wells to pump groundwater. As a result, the water table in the plains of Ningxia fell sharply, causing the formation of an underground hopper area 449 square meters. km under the city Intsyuan.
Of 665 400 Chinese cities use groundwater as their main source of drinking water. In particular, in the cities of the north underground waters cover 65% of domestic needs, the needs of 50% and 33% of agricultural water requirements.Source: epochtimes.ru.