After the high temperature "exit", where is the drought in the Yangtze River Basin?

Cover reporter Teng Yan intern Yue Siwen Zhou Xin

21.75 meters, this is the water level of the Hydrological Station of Dongting Lake City Lingji City at 8 o'clock on August 28. The water level, known as the water meter of Dongting Lake and the Yangtze River Basin, has reached the lowest in August in the past 50 years.

Fan Zhongyan's "Yueyang Tower" is "distant mountains, swallow the Yangtze River, Haohao soup, and endlessly endless".

Mr. Wang from Changsha City, Hunan Province drove to Dongdong Ting Lake Nature Reserve in Yueyang City for two hours. In his photos, a fish with about three palms was dried in the grass, and some fish floated on the lake ...

There are some dead fish floating on the water on the shore of the National Nature Reserve of Dongdong Ting Lake (the interviewees are confession)

Poyang Lake, more than 800 kilometers away, also has similar dilemma. "I can't see the water by the lake, and the yellow is full of weeds." Mr. Tu, a large household in Lushan, Jiujiang, Jiangxi, described the "strange" Poyang Lake today.

Since July, the most serious weather drought in the Yangtze River Basin has been in 1961 to the present, and Poyang Lake and Dongting Lake have continued to shrink. The drought also has a different degree of impact on the provinces of the Yangtze River Basin. Data from the Ministry of Water Conservancy showed that as of August 22, the drought in 10 provinces and cities in the Yangtze River Basin was 48.48 million mu, mainly distributed in Chongqing, Sichuan, Hubei, Hunan, Anhui, Jiangxi, Jiangsu and other places.

"If there is no particularly obvious precipitation in early September, the drought may last until mid -to -late September. Now, if the internal drought in the next 20 days cannot be relieved, it will be very unfavorable to the production of autumn grain." Cover reporter said.

Drought "rare in the same period of the same period"

"For many years in the same period", Liu Zhiyu, deputy director of the Information Center of the Ministry of Water Resources, at the press conference of the "Yangtze River Basin Anti -Qiu Grain Harvest" held on August 17, described the drought in the Yangtze River Basin this year.

High temperature and rain, less water from rivers, continuous lower water levels, insufficient water storage of small and medium reservoirs, and lack of soil in many places are specifically reflected. Data show that since July, the Yangtze River Basin's precipitation is 4.5 % less than the same period of the same year, the least in history since 1961. Most of the watersheds exceeded 20 days, and the middle and lower reaches are over 30 days. Among them, the Land of Hunan is over 40 days in a row. In addition, the soil in most areas of the basin is mildly lacking. Among them, Chongqing, Sichuan, Anhui, Hubei, Hunan, and Jiangxi have a moderate lack of soil in 1/3 of the counties and districts.

On August 21, the rivers mussels were dried up and died in the mountains and rivers of Yiyang Hunan (Photography: Cover Journalist Yang Feng)

In fact, the Yangtze River Basin has also occurred in 2006, 2013, and 2017. In particular, the drought in Sichuan and Chongqing in 2006 was the most serious drought since then its own meteorological records.

However, Xu Jijun believes that this year's drought in the Yangtze River Basin is different from 2006. The first is the larger scope. Not only the Sichuan -Chongqing, the middle and lower reaches of the Yangtze River include Hunan, Hubei, Jiangxi, Anhui, and downstream Jiangsu, all of which have suffered serious drought. The second is the beginning time and a long duration. After several obvious precipitation in the Yangtze River Basin in June, there was basically no significant precipitation in July. At the same time, most parts of the basin are high temperatures, which will promote the rapid development of drought. At present, this year's drought is severe compared to 2006.

What does the "two lakes" atrophy mean?

The monitoring of Fengyun Meteorological Satellite at the National Satellite Meteorological Center shows that the area of ​​Poyang Lake's water body has been significantly reduced since July. On August 21, the water body area was about 1010 square kilometers, which was about 67%decreased compared with the same period in the past 10 years. On the same day, the water body area of ​​Dongting Lake was about 546 square kilometers, all of which were the minimum value of nearly 10 years.

Xu Jijun said that under normal circumstances, the precipitation of Dongting Lake and Poyang Lake Basin mainly occurred in April to July. During the period, the "two lakes" would maintain a relatively high water level. By July and August, if the water level of the Yangtze River is high, the water of the "two lakes" will not be rowed out, and even the dry flow of the Yangtze River will flow into the lake area, which will lead to a higher flood level in the lake area. After August and September, as the water level of the Yangtze River decreased, the "two lakes" water will gradually return to the dry flow of the Yangtze River, and the water level of the lake area will decrease. However, in June this year, the dry flow of the Yangtze River was not too high. The water in the upstream in July was significantly less. The water level in the Yangtze River was nearly five or six meters lower than the year. The water in it flowed out, and the water level removal time was more than a month earlier than the year in advance. In addition, the high temperature, the evaporation volume was large, and the water surface of the lake area was reduced rapidly. "

The monitoring of Fengyun Meteorological Satellite shows that the water body area of ​​Dongting Lake has shown a decrease since July. On August 21, the area of ​​water body was reduced by about 67%compared with July 1 (picture source: National Satellite Meteorological Center)

The lack of water in the "two lakes" first affects the surrounding water supply and irrigation. Secondly, the ecology of the lake area will also be affected to some extent. For example, some of the bottom -living animals living in the clay beach may be exposed to high temperature and drought. influences. In addition, some floating plants and aquatic plants are replaced by some terrestrial plants.

Regarding the cause of drought this year, at the aforementioned Ministry of Water Resources, Liu Zhiyu pointed out that under the background of global warming, affected by the continuous La Nina incident, the Western Pacific subtly high -pressure area was large, strong in strength, and north of the west, and was highly auxiliary high. In the control of the air flow, the entire river basin of the Yangtze River continued to be high temperature and rain, and the main rivers and lakes in the basin were less water. The water level was significantly low.

Safe food security

Yueyang is the main food area south of the Yangtze River. Here, Dongting Lake meets the Yangtze River. Data show that since July 8th, the average rainfall of Yueyang City has been the third low in history since 1961.

Mr. Cai, a large rice planting household in Huarong County, Yueyang City, told reporters that "almost no water" was "almost impossible" from mid -August. "

"Many of the middle rice is dry, and the late rice is not very good." How is the harvest of more than a thousand acres of rice? Mr. Cai judged that the early rice has been collected. At present, the drought is mainly affected by the middle and late rice.

In fact, this year Yueyang City's drought -proof and drought -resistant work was not carried out. A staff member of the Yueyang Water Conservancy Bureau told reporters that "The last rainfall in early July, basically kept the rain, and the reservoir was stored." At the same time, when the Dongting Lake had not dropped to the low water level, it opened 105 culverts 105 places. , Drimp to about 160 million cubic meters to the pupa. However, the critical period of water in the rice in high temperatures requires the contradiction between supply and demand.

On the shore of Poyang Lake, Mr. Tu also encountered drought. He planted grain by himself, and also acquired nearby farmers' food, involving a range of 40,000 to 50,000 mu. "For the case of regeneration rice, droughts lead to more empty shell rate, low rice rate, and high rice rate.

Jiangxi is a major grain -producing province, and the area of ​​Poyang Lake is the main producing area. Data on August 20 showed that 75 counties and cities in Jiangxi reached moderate and above the meteorological drought. The Jiujiang where Mr. Tu is located is one of the areas where the drought is severe.

"I planted more than 1,000 acres of rice myself in the past 1,233 to 1,4500 pounds. This year, 1,000 pounds is okay." How can there be no water during the growth period? "

Middle rice is the main food that is currently the most affected by the drought. It is understood that the Yangtze River Basin generally grows one season of rice and double -season rice. Among them, the double -season rice is divided into early rice and late rice. Beginning in mid -August, the middle rice in the south has entered a period of pumping and flowering. It is sensitive to temperature and water. High temperature drought will lead to a decline in pollen activity and seriously affect the yield.

On August 24th, the executive meeting of the State Council asked for drought resistance and disaster and mitigation, and took out 10 billion yuan of drought to relieve disaster relief from the central reserve fee, focusing on supporting Chinese rice drought resistance. The Ministry of Agriculture and Rural Affairs, the Ministry of Water Resources, the Ministry of Emergency Management, and the China Meteorological Bureau jointly notified on August 22, requiring to go all out to win the "Battle of the Autumn Grain Harvest and Fighting".

"Wild water sources, scientifically control water, and save water." The staff of the Yueyang Water Resources Bureau introduced the aforementioned Yueyang City Water Resources Bureau. The well can irrigate more than 70 acres of land. On the other hand, fine management, how much is needed. The biggest goal is to keep harvest, protect food safety, and drink.

The monitoring of Fengyun Meteorological Satellite shows that the water body area of ​​Poyang Lake has been significantly reduced since July. On August 21, the area of ​​water body and the water body area on July 10 were reduced by about 69%(picture source: National Satellite Meteorological Center)

"The current water conservancy facilities used for drought resistance are mainly reservoirs. Some pump stations pump from the river and the reservoir. There are also water -conditioning projects, from one reservoir to another. And irrigation needs, this is an emergency measure, "Xu Jijun introduced.

The Ministry of Water Resources has implemented the "Special Action for Joint Disclosure of Drought Restaurant in the Yangtze River Basin Reservoir Group" from 12:00 on August 16. The king of the water and drought disaster defense of the Ministry of Water and Drought Disaster said that as of August 23, a total of 1.96 billion cubic meters of water replenishing the upstream reservoir group, Dongting Lake Water System Reservoir Group, and the Poyang Lake Water System Reservoir Group. Liu Weiping, deputy minister of the Ministry of Water Resources, pointed out that the current irrigation water sources and urban and rural water supply in large and medium -sized irrigation areas are guaranteed. Drought and cultivated land is mainly distributed at the end of the irrigation area and "Wangtiantian", which is at the end of the irrigation area and no irrigation facilities. The water supply is mainly affected by small reservoirs or mountain springs and streams as diversified water supply projects.

"Now the Yangtze River Basin, whether it is some large reservoirs and small reservoirs, are conducting drought resistance. The primary goal is to resist drought, and of course, it is necessary to prevent drought and flooding from rotating." Xu Jijun said.

Will there be drought in summer and autumn

The long -lasting high -temperature weather process came to an end. Shi Yan, an analyst of China Weather Network, introduced that under the "pinching" of cold air and typhoon north and south, the subtropical high pressure overall has a trend of eastward and south pressure, and the intensity will also weaken.

In addition, Henan, Anhui, southern Jiangsu, central Hubei, most Zhejiang, eastern Fujian, northern Sichuan and western Sichuan Basin will welcome rainfall, which is good for the alleviation of meteorological drought. The area still maintains high temperature and rainy weather.

"Crops are now the most 'thirsty', and they need precipitation most." Xu Jijun said that now he is more concerned about September. If there is no particularly obvious precipitation in early September, the drought may last until mid -late September, but this time is a crop for crops. Growth is very critical. "If the internal drought in the next 20 days cannot be relieved, it will be very unfavorable to the production of autumn grain."

"I am very worried that summer and autumn is drought, and the possibility is relatively large." Xu Jijun said that it is recommended that there are more places to prepare more water sources. Plastic areas or mountainous areas should do a good job of groundwater emergency mining. Measures such as rainfall. In addition, we must strengthen water saving management.

Drought is "chronic disease"

July was the main flood season of the Yangtze River Basin. This year's "flood season" is not common, which brings difficulty to the reservoir. Xu Jijun said, "Some reservoirs are in advance to prepare to stop the floods in advance, but the floods are not coming. If you want to supply water to keep irrigation, the pressure is relatively large. Many reservoirs are now running at low water levels."

Xu Jijun said that floods are like acute diseases, and emergency treatment must be treated after the occurrence. Drought is like chronic diseases. At the beginning, there is no problem. After a few months, it will become more and more serious, and it is difficult to judge how the drought in the next step is to develop in this process. The formation of drought disasters is a gradient process, the longer the duration, the greater the harm.

"This time the drought of the Yangtze River is indeed exposed to some improved places." Xu Jijun believes that the corresponding basic research, technology research and development, and platform construction should be strengthened in drought monitoring and early warning. For example, according to the current weather information, the development trend of drought is deduced. Second, for drought, the current engineering means are relatively weak. The construction of the reservoir is more considering flood control, water supply and irrigation, and water supply and irrigation are also under normal conditions. When they encounter extreme conditions, there are not many measures. For example, this time, if the reservoir reserves a large amount of water in advance or has a reserve groundwater source, it will be much better. Third, in the long run, we must strengthen drought resistance. In the long run, we should do a good job in engineering planning to respond to climate change. In addition, it is necessary to do a good job of reservoir scheduling from flood control and drought resistance. "A very critical point, how to control the flood limit of the reservoir, it may be good for leaving more water, and more water resistance will be good, but at the same time, it will be good, but at the same time, it will be good, but at the same time, it will be good. To bear a certain risk of flood prevention, we must make a good plan and balance. "

"To strengthen the study of climate change." A professor in the field of water conservancy from Wuhan University told reporters, "Climate warming is a major trend. One encounter in ten years? In this case, it is necessary to study how to build water conservancy projects. "

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