Either it doesn’t rain or it rains like crazy. Why does the heavy rain in the south continue to be a “wheel war”?
Beginning in June every year, central and eastern my country gradually enters a period of concentrated precipitation, but this year’s June is particularly special, with heavy rains ranging in scope, intensity, and rainfall. This year, floods caused by rainfall in the south have affected tens of millions of people in more than 10 provinces including Guangxi, Guizhou, Hunan, Sichuan, and Jiangxi.
Why is there so much rain in the south this year? What is the weather trend in the future?
Data map: On June 13, heavy rain poured down in Pujiang County, Jinhua City, Zhejiang Province, and traffic police were on duty in the rain. , blocking vehicles from entering the flooded road section. Photo by Zhang Haoyue from China News Service
It keeps raining
Nearly one-sixth of the country has received more than 200 millimeters of rain
Looking back on the past June, the southern region* ** There have been five large-scale rainfall events. From June 2 to July 2, the Central Meteorological Observatory has issued heavy rain warnings for 31 consecutive days.
Judging from the statistics of the China Meteorological Administration, it is not an exaggeration to say that the rain in the south this year is "splashing water":
Nearly 1.5 million square kilometers of land have accumulated rainfall. Rainfall exceeding 200 mm;
700,000 square kilometers of land experienced rainfall with cumulative rainfall exceeding 300 mm;
About 50,000 square kilometers experienced rainfall with cumulative rainfall exceeding 500 mm;
National precipitation distribution in June. Picture source: Central Meteorological Observatory
How much rain is this?
The amount of water in 12 Taihu Lakes fell in Hubei
According to the analysis of the Central Meteorological Observatory, the rainfall in this year’s flood season has Three characteristics: heavy rain covers a wide range, has heavy rainfall, and is extremely extreme.
The heavy rainfall during this year’s flood season can be seen from the data. Nearly one-sixth of the country received more than 200 millimeters of rainfall.
According to statistics, the national average rainfall in June reached 110.9 mm, 12% more than the same period in normal years, the ninth most since 1961 (1998 was the highest in the same period in history). If ranked by province, Hubei had the most precipitation in the same period in history, and Jiangsu and Heilongjiang both had the most precipitation in the same period in history.
How much? Taking Hubei Province as an example, the rainfall converted into volume water is about 53 billion cubic meters, which is equivalent to 12 Taihu Lake and 0.5 Qinghai Lake!
Water volume Comparison picture source: Central Meteorological Observatory
Among the major cities in the south (national observation stations), judging from the rainfall rankings in June, Wuhan, Hubei Province ranked at the forefront with 419 mm, followed by Hangzhou, Hefei, and Nanjing. , their rainfall is above 300 mm.
"The rain is so heavy that it cannot be contained in one place." The rainfall in Yangshuo County, Guilin City, Guangxi Province reached 327.7 mm on June 7, breaking the local record for the most rainfall in a single day. You must know that Beijing's average annual rainfall is only 532.1 mm.
How widespread is this rain?
Most of the south is soaked in rain for half of June
The rainfall process that started on June 21 is called this year The heaviest rainfall since the beginning of the flood season, this round of heavy rainfall lasted for a long time and affected a wide range of areas. More than 10 provinces including Guizhou, Chongqing, Hunan, Hubei, Jiangxi, Anhui, Jiangsu, Zhejiang, Shanghai and Guangxi were targeted by it.
According to the Central Meteorological Observatory, in June, 15 southern provinces (autonomous regions and municipalities) had rainfall of more than 250 millimeters covering an area of 1.1 million square kilometers, and rainfall of more than 400 millimeters covered an area of about 276,000 square kilometers.
During the entire month of June, except for central and northern Yunnan, most of the south was soaked in rain for half of the time. In some places such as northeastern Guangxi and western Yunnan, the number of rainy days exceeded 25 days.
According to the previous judgment of the National Climate Center, from June to August
my country's climate conditions were generally deviated, with more extreme weather and climate events, and the overall precipitation pattern was "more in the north and south, less in the middle" In terms of spatial distribution, floods are more serious than droughts. In other words, heavy rains may hit both the north and the south in the future.
On the afternoon of June 18, a sudden heavy rain fell in Kunming City, Yunnan Province, and citizens went out in the rain. Photo by China News Service reporter Liu Ranyang
How heavy is the rain?
Precipitation in many places has exceeded historical extremes
Generally from April to early June, South my country is in the pre-flood season and some areas south of the Yangtze River are in the rainy season. By mid-June, the rain belt will move northward and enter the middle and lower reaches of the Yangtze River.
He Lifu, chief forecaster of the Central Meteorological Observatory, said that judging from the phase characteristics, the rainfall in the south this year is relatively normal, but the intensity is indeed relatively strong. Recently, some southern provinces, such as eastern Hubei, eastern Sichuan, Chongqing and other places, have experienced 2-4 times more rainfall than the same period in normal years, and even 5 times more rainfall in some places.
Since June, 41 national meteorological observation stations in the southern region have exceeded the extreme value of daily rainfall in June, and 5 stations including Yangshuo in Guangxi have exceeded the historical extreme value.
The consequence of such heavy rainfall is that the water levels of rivers, lakes and reservoirs in the Yangtze River Basin have risen rapidly, some rivers have experienced super-alert floods, some tributaries have experienced unprecedented floods, and local areas have suffered from severe geological disasters.
On June 22, the Chongqing Hydrological Monitoring Station issued a red flood warning. This was the first time the station had sounded a red alert since its establishment in 1940.
On the afternoon of June 29, a community in Hongshan District, Wuhan City was flooded with water. It rained continuously. Fish in the lake in the community fled. Some citizens fished on the waterlogged road after the rain.
Picture source: People’s Vision
Heavy rain warnings have been issued for 31 consecutive days
Why do heavy rains continue to rain in the south this year?
In June, our country will enter a period of concentrated precipitation. This also declares that our country has fully entered the main flood season. Rainfall requires conditions. According to the analysis of the Central Meteorological Observatory, water vapor, rising movement and duration are the key reasons for the frequent occurrence of heavy rainfall.
Hu Xiao, chief meteorological analyst of China Weather Network, said that the most important reason why the rainfall during the flood season is so violent, long-lasting and powerful is that the water vapor conditions are good. For example, the plum rain that is entrenched in the Jiangnan and Jianghuai areas is continuous rainfall caused by sufficient water vapor.
In addition, as the "driving force" behind the weather in my country's flood season, the strength and location of the subtropical high determines the changes in the distribution of rain belts in central and eastern my country.
Experts analyzed that in previous years, the subtropical high pressure was located in the ocean east of Taiwan, but this year its position is obviously westward, closer to my country, and stronger. Therefore, it contributes to the humid airflow affecting my country. A helping hand.
The picture shows that on June 22, Tongzi County suffered severe heavy rain and flooding, and firefighters carried out rescue operations in the flood. Photo courtesy of Zunyi Fire Rescue Detachment
In the future, it will rain again
A new round of heavy rain has arrived, and Beijing, Tianjin and Hebei will also join
The latest forecast from the Central Meteorological Observatory It shows that from July 1 to 3, rainfall was still strong in southeastern Sichuan, central and southern Chongqing, Guizhou, Yunnan, western and southern Hubei, and central and northern Jiangnan.
Chen Tao, chief forecaster of the Central Meteorological Observatory, analyzed that the intensity of this round of rainfall is relatively large and overlaps with the area affected by the heavy precipitation process at the end of June. The cumulative precipitation will be 1 to 2 times more than the annual average.
It is worth noting that North China, Huanghuai and other places have also joined the "rainfall camp". From July 1st to 3rd, North China and Huanghuai will experience a rainfall process, with moderate to heavy rains and local heavy rains in some areas of Beijing, Tianjin and Hebei, accompanied by strong convective weather such as thunderstorms, strong winds or hail.
On the 30th, the mountain roads in Wucheng District were flooded. The towns provided photography
Critical period for flood control!
Regional major floods may occur
On June 29, the Ministry of Water Resources held a video conference to analyze and judge the rain and water conditions and arrange the deployment of defense work. This meeting mentioned that it is expected that there will be rainy areas in the north and south during the main flood season. Regional major floods may occur in the Yangtze River, Yellow River, Haihe River, Pearl River, Songhua River, Liaohe River and other river basins. Local heavy rains and flash floods may occur frequently. Reservoirs can safely handle floods. The pressure is high and the flood control situation is not optimistic.
Wang Zhangli, deputy director of the Flood and Drought Disaster Prevention Department of the Ministry of Water Resources, said on June 30 that July and August are critical periods for flood control in my country. River floods are becoming more frequent and require greater attention.
“This year’s flood situation presents four major characteristics – there are many heavy precipitation processes, many rivers exceeding warning levels, concentrated floods, and high river water levels.” Liu Zhiyu, deputy director of the Hydrology and Water Resources Monitoring and Forecasting Center of the Ministry of Water Resources, analyzed.
Wang Zhangli introduced that since this year, heavy rains and floods have occurred frequently in our country, with many processes and large amounts of water. Since June, major control stations of rivers and lakes such as the Xijiang River and Beijiang River in the Pearl River Basin, the upper reaches of the Yellow River, and Taihu Lake have experienced floods exceeding the warning level (flow rate). Floods in some small and medium-sized rivers have occurred frequently, and regional heavy rains and floods have been heavier than normal.
Since June, a total of 250 rivers across the country have experienced floods exceeding warning levels, accounting for 92% of all rivers exceeding warning levels, mainly concentrated in Guangdong, Guangxi, Guizhou, Hunan, Hubei, Jiangxi, Sichuan, Chongqing, Anhui and other provinces, autonomous regions and municipalities.
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