Frequent mountain fires out of the river!How drought is the south under extreme high temperature?

Since this summer, the area of ​​the Yangtze River Basin in my country has not only frequently exceeded the 40 ° C mark frequently, but also rare and less precipitation. Under such meteorological conditions, different degrees of meteorological drought occur in many places. Affected by it, the water level of the Yangtze River and Dongting Lake and Poyang Lake were the lowest since the actual test records, and the water storage of small reservoirs in some areas was seriously insufficient. To what extent does the southern precipitation less this summer? How will the high temperature drought develop in the future? When is it expected to relieve? China's weather network inventory meteorological big data, telling you how drought is the south in extreme high temperature.

Most of the south suffers from high temperature and precipitation.

Since July, the Yangtze River Basin has encountered severe weather droughts, and rare "main flood periods" appeared. According to Wang Weiyue, a meteorological analyst of China Weather Network, from the perspective of the national high temperature daily number of daily numbers, since July, high temperature weather has appeared in most south of the south south south of the Qinling Huaihe River. As of August 20, high temperature days from Sichuan Basin to Jianghan, Jianghuai, most Jianghuang, Jiangnan, northern and eastern parts of South China reached more than 20 days, especially in the high temperature days in the Yangtze River Basin and Jiangnan area. Essence

Since July, precipitation in most parts of the south is significantly less than that of the same year. Among them, central Sichuan Plateau, Sichuan Basin, Jianghan area, southern Jianghuai, central Jiangnan region and east, northeast of South China, and northwestern parts of parts and northwestern parts are more than 50 % less than the same period of the same year, especially in southwestern Chongqing and northeast Jiangxi. The local area precipitation in western Fujian is less than 80 %.

From the perspective of the national precipitation distribution map, from July 1st to August 20th, the cumulative precipitation of the Sichuan Basin, Jianghan, Jiangnan, Jianghuai, Northwest China, and northern South China was less than 200 mm. Among them, the south of the Sichuan Basin, the southwest of Chongqing, the northwest of Hubei, the central Zhejiang and southern parts, the eastern part of Jiangxi, the northwest of Fujian, and the southern part of Jiangsu have accumulated more than 100 mm in more than 50 mm, and even less than 50 mm.

From the perspective of the national precipitation daily distribution map, most of the cumulative precipitation days in Sichuan Basin, eastern Hubei, northeast of Hunan and southeast, central Jiangxi and north, southern Zhejiang, northwestern Fujian, and northwestern Fujian The cumulative precipitation days in the northeast of Jiangxi are less than 8 days.

Rain in these areas breaking the historical record of nearly 80 % of Nanchang Nanchang

This summer, some parts of the south have experienced the least rain in the same period, and Nanjing, Nanchang and other places even have nearly 80 % less. According to the cumulative precipitation statistics from July 1st to August 20th, in eastern Tibet, central Sichuan Plateau, southern Sichuan Basin and central parts, southwestern Chongqing, northwestern Hubei, southern Yunnan, west of Guangxi, central Jiangxi, north, southeast Zhejiang Some places in the southern part of the ministry, southeast Anhui, and southwestern Jiangsu have the least precipitation in the same period.

Among the big cities, the accumulated precipitation in Nanjing in Jiangsu was 333.5 mm in the same period, and only 47.5 mm this year; while Nanchang, Jiangxi, the accumulated precipitation of the same period of the same year was 251.3 mm, only 32.5 mm this year, nearly 80 %; It is also very scarce, and it breaks the minimum record of the cumulative rainfall in the same period.

14 provinces, districts, cities, cities, cities, municipalities, droughts and subtropical high pressure abnormality are the main causes

Affected by high temperature and rainy weather, the drought in the Yangtze River Basin developed rapidly. Since July, the Yangtze River Basin Sichuan, Chongqing, Hubei, Hunan, Anhui, Jiangxi and other provinces and regions and municipalities have occurred in many provinces and cities. This year, the high temperature and drought of the Yangtze River Basin showed a retransmitter as a whole, which have the characteristics of long duration, wide influence, strong strength, and extreme extremes. At present, rivers are significantly less water, and the water level continues to decline. The water level of the Yangtze River and Dongting Lake and Poyang Lake are 4.85 to 6.13 meters lower than the same period of the year. The water body area of ​​Dongting Lake and Poyang Lake was reduced by 75%compared with June, and the water storage of small reservoirs in some areas was seriously insufficient.

Why is the main flood season that has not ended, but the Yangtze River Basin has a drought? Guo Guangfen, deputy director of the Wuhan Regional Climate Center, explained that the subtropical high -pressure abnormality is the most direct and most important reason for drought. The Western Pacific subtropical high pressure is significantly stronger than the same year, stable and long -lasting time, and the control range of the control with the mainland high pressure is wider. Especially since August, the strength of the high -voltage center has increased rapidly, including the control range of the middle and lower reaches of the Yangtze River and southern regions. It affected the high -temperature weather above 40 ° C in the Yangtze River Basin.

In the main flood season, the severe drought in the middle, middle and lower reaches of the Yangtze River is relatively rare. Lu Juan, director of the flood resistance and disaster reduction center of the Chinese Academy of Water Resources and Hydropower Science, pointed out that since 2000, many drought incidents have occurred in the Yangtze River Basin in my country. The more typical years include 2006, 2011, 2013, and 2019. Among them, in 2006, it was also a high -temperature drought in the entire basin, and the worst drought was Sichuan and Chongqing.

This year's middle and lower reaches of the Yangtze River are similar to the reasons for Sichuan and Chongqing Drought in 2006. They are all caused by the main flood season of the Yangtze River Basin caused by abnormal atmospheric circulation. Although the drought affected and the disaster was heavy at that time, the two provinces (cities) of Chongqing and Sichuan (cities), which were mainly drought in the upper reaches of the Yangtze River, were concentrated in the dry flow of the Yangtze River Basin. Compared with 2006, this year's drought has a large range of space, covering the upper, middle reaches and downstream of the dry flow of the Yangtze River.

In the end of August, the increasing rainfall in the West China area is expected to alleviate

At present, the continuous development of drought has reached about 40 days, and it may continue to develop in the next week. According to the monitoring of meteorological drought on August 25, southern Jiangsu, southern Jiangsu, southern Anhui, southern Henan, Hubei, Zhejiang, Fujian, Jiangxi, Hunan, Guizhou, Chongqing, most Sichuan, southeastern Shaanxi, southeastern Gansu, and central Tibet, etc. There are moderate to severe meteorological droughts and local special droughts.

The Central Meteorological Observatory predicts that in the next 3 days, there will be heavy rain in Henan, most of Anhui, southern Jiangsu, most of Zhejiang, northeast of Fujian and north and west of Sichuan Basin, which will be good for meteorological drought, but other areas of most areas will Still maintaining high temperature and rainy weather, and the drought of meteorological will continue to develop. The Central Meteorological Observatory continued to issue meteorological arid and orange warning.

Wang Weiyue said that at the end of August, affected by the subtropical high pressure, the number of precipitation in the West China will increase. Like the central and northern parts of Sichuan and southern Shaanxi, it will continue to rain from the 26th to the 30th, and the drought of meteorological drought will be significantly relieved; while the rain and while in some areas of Hunan, Jiangxi, Anhui, and Hubei are still relatively weak, the drought of meteorological drought will continue, and the drought situation will still be still in the situation of the drought situation. not optimistic.

Sichuan Observation (Source: China Weather Network)

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