Interview experts
Gao Jianwei (Senior Engineer, Physical Geological Data Center, China Geological Survey)
Zheng Kebang (Director of Expert Committee of China Geothermal Industry Working Committee)
Cheng Jiqun (Deputy Chief Physician, Department of Dermatology, Third Medical Center, PLA General Hospital)
With the coming of winter, soaking in hot springs has become a popular choice, which can not only relieve physical fatigue, but also relieve mental stress, especially for people living and working in cities, which is a good way to relax and keep fit.
With the continuous warming of the "hot spring economy" in various places, the concept of hot springs has long been "generalized", and some fake hot springs have begun to confuse the audience and fabricate figures, causing great losses to consumers. What water can be called a hot spring? What are the precautions for ordinary people to soak in hot springs?
Explore:
What exactly is hot spring water?
What is a "hot spring"? In fact, there is no authoritative and official definition of "hot spring" in China.
Due to the influence of natural environment and geological conditions, the causes of hot springs are different. In short, they can be summarized into two categories: one is sulfur-containing hot spring water formed by magmatism (or volcanism) in the earth's crust, and the other is carbonate hot spring water formed by surface water infiltrating into strata. However, the formation of these two kinds of hot springs has preconditions: there must be geothermal energy here to produce hot springs.
Gao Jianwei explained that due to plate movement, tectonic and magmatic activities (including volcanic eruptions) are frequent in some places. If the crustal plate movement causes the surface to uplift and there is uncooled magma below, it will continuously release heat and become a heat source. At this time, if there are water-bearing rocks in the nearby pores, the heated water will expand and form hot springs. This kind of hot springs mostly appear in areas with intense geological movement, and Yangbajing Hot Springs in Tibet, located on the Qinghai-Tibet Plateau, is a typical representative.
The other is a hot spring formed by surface water infiltration circulation. The principle is that in some areas, surface water such as rainwater seeps into the aquifer inside the earth's crust and then forms groundwater. Groundwater is heated by geothermal energy below to become hot water. If there is a dense and airtight rock layer above the groundwater, it will "lock" the groundwater and gas inside and the pressure will increase. Once cracks appear in the upper strata, groundwater will gush out.
Because of the large hydrostatic pressure difference, this kind of hot spring is more common in valleys, such as Chengde City, Hebei Province, which is located in the valley of Yanshan Mountains. Because of its rich geothermal water and thermal resources, it used to be called "Jehol".
But in recent years, with the large-scale development of tourism, the concept of hot springs has long been generalized. Zheng Kekun, director of the Expert Committee of China Geothermal Industry Working Committee, pointed out that except natural hot spring water, geothermal water with water temperature higher than 25℃ is extracted by underground drilling; Geothermal water heated and pressurized at the outlet of water flow is called hot spring water.
It is under the background of this standard generalization that the hot spring industry has become a "mixed fish and dragons", coupled with the uneven distribution of geothermal resources in China, and even the emergence of "fake hot springs", which makes "hot springs" become "expensive baths" and lose its own significance.
Forge:
How to distinguish "Gui Li" in hot springs?
In addition to natural hot springs, there are many artificial hot springs in China at present, and hot spring water is extracted from deep fault zones by drilling wells. Zheng Kekun said that this kind of hot spring is also called hot spring well, and the water temperature can reach above 25℃. Because it is artificially mined, it cannot be called a natural hot spring, but only a "hot spring" or an "artificial hot spring".
However, the water temperature of many hot spring wells is low, and the water temperature loss of hot springs during transportation is large, which can not meet the requirements of customers. It is necessary to use a heat exchanger to keep warm, that is, to warm up during transportation or at the exit. This kind of hot spring is called heating hot spring, which is a method to make up for the temperature loss artificially.
As long as the outlet temperature and trace elements meet the standards, hot springs that only exchange heat without water can also be considered qualified. But some behaviors that make a fuss about "water" are naked "counterfeit products".
Gao Jianwei said that some hot spring water comes from the surface, and it is "heated" along the underground pipeline and then returns to the ground, giving people the illusion of underground hot spring water; In some areas, the amount of underground water is insufficient, so the hot spring water is repeatedly heated and recycled. This kind of hot spring is very impure, which is very different from natural hot springs and its effect is greatly reduced.
What's more, some scenic spots or businesses that don't have hot spring conditions at all, in order to attract consumers, pretend to be hot spring water by adding sulfur powder and blending artificial hot water, so as to achieve the purpose of confusing the real. According to informed sources, the price of sulfur powder is not high, only 4-6 yuan per catty, but the hot spring water brewed with 1 catty of sulfur powder is enough for a 40-square-meter pool, which is considered as a "high-yield product".
In the eyes of many consumers, the biggest charm of hot springs is the curative effect. As a result, hot spring enterprises have spared no expense in publicity. "Contains a variety of minerals and trace elements beneficial to the human body, can beauty beauty, strengthen the body, and treat arthritis and skin diseases ..."
How do ordinary consumers distinguish between true and false hot spring water? Zheng Kekun said that the simplest thing is to judge by the state after soaking: the real hot spring water comes from the depths of the surface and contains a lot of sodium, which belongs to soft water. People can feel slight buoyancy when soaking, and the skin feels greasy after soaking. On the contrary, fake hot spring water belongs to hard water, and its composition is mainly calcium. After soaking, the skin will turn white and wrinkle.
True and false hot springs can also be distinguished by region. According to the data, hot springs in China are mainly distributed in Tibet, Yunnan, Taiwan Province, Guangdong and Fujian, accounting for more than 50% of the total number of hot springs in China, followed by Liaoning, Shandong, Jiangxi, Hunan, Hubei and Sichuan. Geothermal resources are mainly distributed in tectonic active zones and large sedimentary basins. The former has concentrated resources, such as Tibet, Yunnan, Sichuan, southeast coastal areas and Liaodong-Jiaodong areas. The latter resources are widely distributed, such as Beijing-Tianjin-Tangshan area in North China Basin. "The geothermal resources in the northwest of China, the Loess Plateau, the Huanghuai area and the Yangtze River Delta are not rich, especially in the Loess Plateau." Gao Jianwei said.
Who are not suitable for hot springs?
Many people like to soak in hot springs for more than half a day, but they don't know that this practice is likely to "soak too much" and even feel unwell and suffer from "hot spring disease".
In fact, according to the composition of water, hot springs can be divided into acid springs, alkaline springs and neutral springs: acid hot springs can promote blood circulation, improve vascular function and have a certain bactericidal effect, but they are not suitable for patients with kidney disease and people with bad stomachs. Alkaline spring has a certain curative effect on dermatosis, rheumatism and arthritis, but its "side effects" are also obvious. People who are allergic to skin are not very friendly and easy to "overexert".
"Even some people with poor skin foundation, such as people with allergies, will suffer from xeroderma. Skin scratches and infections can easily lead to rashes and folliculitis. Such patients are more common in clinic. " Cheng Jiqun said.
Some people may have chest tightness, palpitation, shortness of breath, dizziness and other symptoms because of high water temperature and accelerated blood circulation, and even lead to an increase in blood pressure of some patients with cardiovascular diseases and physical discomfort in a short time. Cheng Jiqun suggested that patients in the acute stage of various diseases, patients with basic skin diseases, elderly people with chronic diseases such as hypertension, diabetes and heart disease, and underage children are not suitable for hot springs.
"Especially in the northern region, the winter climate itself is relatively dry, and ordinary people can easily cause skin diseases by soaking in hot springs for a long time. After soaking in hot springs, you should follow the principle of moderation and do a good job of moisturizing. If possible, try to go to a high-star hot spring club or a hot spring with better sanitary conditions and water quality, which can also reduce the probability of' hot spring disease'. " Cheng Jiqun said.
Produced by: Popular Science Central Kitchen
Producer: Beijing Science and Technology News | Beike Media
Welcome to share with friends.
WeChat official account, newspapers, etc.
Please send an email to bjkjeditor @163.com.
Refuse to reprint without authorization, and offenders will be prosecuted.
Identify the QR code and download the "Beijing Science and Technology News" client