Why is there so much rain this year?

On June 13, taking advantage of the sunny day in the "rain loophole", the reporter came to the Provincial Meteorological Bureau and asked relevant experts to review the continuous rain this year and explore its ins and outs.

It has rained for nearly 100 days since this year.

It rained continuously, as if it were raining every day. This is the feeling of many people, but in fact, how many days has it rained this year?

Liao, director of the provincial climate center, said that since the flood season began this year (from 08: 00 on1October 65438 to 08: 00 on June 1 1 day), the average rainy day in the province is 98.7 days, the sixth in the same period since the meteorological record (195 1). Among them, the number of rainy days in Miluo, Xinhuang, Hongjiang and Zixing 14 counties (cities) is the highest in the same period of local history.

In the meteorological historical records of the provincial climate center, the rainy day was 1970, and in the same period of that year, it rained for 105 days.

As for the rainfall this year, it is also the eighth highest in the same period in history. According to the statistics of the provincial climate center, the average precipitation in the whole province has been 830.4 mm since this year, which is more than normal 18.5%.

Looking back at the rainstorm process from June 65438 to 1 October1,there were 7 rainstorms that affected counties and cities above 10, respectively: March 4 to 5, April 1 13 to 13, 4.

Rainy days, cloudy days and few sunny days.

Does such a long rainy day and so much rain mean that the weather is abnormal and it is an extreme weather and climate event?

Liao said that in general, extreme weather and climate events refer to small probability events that occur once in 50 years or once in 1000. At present, it can be called abnormal and extreme. From 1 to March, the sunshine hours and days are the lowest in history.

According to the statistics of the provincial climate center, from/kloc-0 to March, the sunshine hours in the whole province were only 1 00.8 hours, 86.6 hours less than normal, the lowest since 195 1 year. In addition, only 18.6 days of sunshine appeared on average in three months, which was 16.2 days less than normal, and the number of sunshine days also hit a new low since meteorological records were recorded.

There are many rainy days, cloudy days and few sunny days, which makes people feel that it has never been sunny this year.

With the rain, it is low temperature. According to the statistics of the provincial climate center, the average temperature in the province this year is about 65438 0 degrees Celsius lower than normal.

Rainy weather combined with low temperature may make people feel wet and the rainy season is long and unbearable.

Rain has nothing to do with the Year of the Water Dragon.

In the face of some continuous rain, there is online news that 20 12 is the the Year of the Loong of Renchen in the lunar calendar, and the five elements belong to water, so it is called the the Year of the Loong of Renchen once in 60 years. The Book of Changes says that "the dragon rides on the dragon's back and flies into the sea". This is a year of abundant water and grass, so there will be a lot of rain this year.

According to the analysis of climate data, the average number of rainy days in our province this year is the sixth highest since 195 1, the average rainfall is the eighth highest, and the rainfall intensity is the worst in 60 years.

Liao analyzed that rainfall is the result of the interaction between cold air and warm and humid air. Since the beginning of this year, due to abnormal atmospheric circulation, frequent cold air, active water vapor transport in the south and the confluence of cold and warm air in the south, it has been raining continuously.

According to the reporter's understanding, the "Water Dragon Year" is called the year of flourishing water in folk customs, which means "good weather, peaceful country and people's safety", and there is no such thing as "rainy".

The population of rice planthopper is large and its history is rare.

"This year's rainstorm weather appeared early, with heavy degree and wide distribution, which had a great impact on production and life." Li Jizhou, senior engineer of Emergency Disaster Reduction Department of Provincial Meteorological Bureau, introduced the impact of this year's rainfall.

As the rainstorm started earlier, our province entered the flood season earlier than in previous years. On March 8th 10, the earliest flood peak process occurred at Changsha Station of Xiangjiang River since 1998, and the flood peak water level was 32.3m.. At the same time, frequent and high-intensity rainfall leads to high soil water content and frequent geological disasters of mountain torrents.

Rainy days, less sunshine, slow plant growth, affecting crop yield. According to the data of agricultural department, the growth period of early rice in central and northern Hunan is expected to be delayed by about 2 days due to the rainy weather.

Shuai Xiqiang, director of the Agricultural Meteorological Center of the Provincial Meteorological Bureau, also pointed out that the number of rice planthoppers this year is rare in history. Because it is difficult to control rainy weather, rice diseases and insect pests are the most serious and extensive in recent years.

Late rain concentration period:

Late June to early July

"The drought and flood disasters in our province may be more serious this year than last year." Liao believes that the later rainfall is relatively concentrated in late June to early July. In addition, during the midsummer, due to the typhoon, there may be heavy rainfall in eastern Hunan and southern Hunan.

Li Jizhou suggested that during the rainfall concentration period from late June to early July, possible storms and floods and the disasters such as flash floods, landslides and mudslides induced by them should be prevented as early as possible, and at the same time, adequate preparations should be made to prevent typhoons. In order to prevent the high temperature weather that may occur after the rainy season ends in mid-July, it is necessary to do a good job of water storage and conservation in reservoirs and carry out artificial precipitation enhancement and drought relief in due course.

Zhou Hui, chief forecaster of the Provincial Meteorological Observatory, said that in the next 10 day, it will be cloudy and rainy in northern Hunan and rainy in southern Hunan, with the strongest precipitation from 15 to 16 and heavy rain in Chenzhou and Yongzhou. Due to the recent heavy precipitation and loose soil in southern Hunan, it is necessary to strengthen the prevention of geological disasters caused by heavy precipitation.

Soil water content tends to be saturated, and the water level of rivers and lakes is high.

Long-term rainfall leads to frequent dangers.

Our reporter Liu Dexin.

Long-term rainfall has brought great pressure to the flood control work in our province.

According to the provincial defense index, due to continuous rainfall, the soil water content tends to be saturated, the water level of rivers and lakes is high, and many dangers occur frequently in the province.

Water conservancy projects store more water, and their flood control capacity is reduced. According to the data at 8: 00 on June 1 1 day, the total storage capacity of nine major large reservoirs in the province, such as Wuqiangxi and Zhexi, was 654.38+03.4 billion cubic meters, 2.7 billion cubic meters more than the same period last year.

The water at the bottom of the river is high, which is prone to floods exceeding the warning water level. On June 9th, the water level of Chenglingji Station in Dongting Lake was 30. 10 m, 2.6 m higher than the average of the same period last year and 5. 13 m higher than the same period last year. After the heavy rainfall from June 9 to 1 1, floods exceeding the warning level generally occurred in the upper reaches of Xiangjiang River and its tributaries.

The soil water content tends to be saturated, and the probability of landslides and reservoirs suddenly increases. According to the provincial defense general report, from June 4 to 5, five dangerous situations occurred in our province one after another: the tunnel of Zhujiabadi section of Nanhu River in Hanshou County was perforated with water; 1 person died due to the landslide in Xintian Village, Dalan Town, luxi county; The retaining wall of Shaoyang People's Hospital was deformed and collapsed, resulting in the death of 1 person; Land valley landslide in Sheikh Township, Wulingyuan District, Zhangjiajie City, etc.

Characteristics of rainfall this year

Our reporter Liu Dexin.

Since the beginning of this year, the rainfall in the whole province has obvious characteristics such as more rainy days, obvious process and uneven distribution in time and space. Generally speaking, there is a basic trend of more north and south, less central and less east.

According to the introduction of the Provincial Hydrological Bureau, the time distribution of rainfall this year is obviously more than 65438+ 10, March and May, and less than February and April. From the perspective of spatial distribution, only Shaoyang City in the province has nearly 20% less rainfall, and the rainfall in other areas is higher than the average in the same period of last year. Among them, the rainfall in Yiyang is above 30%, and the rainfall in Changsha, Zhangjiajie and Autonomous Prefecture is above 20%.

Since April 1, the cumulative average rainfall in the whole province has been 5 19mm, which is more than the average of 463mm in the same period over the years 12%. The station with the largest cumulative rainfall in the province is Huangshan Station in Taoyuan County, with rainfall of 1462 mm; The accumulated rainfall at Hengshan Station in Hengyang City is the smallest, only 505 mm..

Reproduction 1998 Rain and Water Regime

Our reporter Liu Dexin.

According to the statistics of the Provincial Hydrological Bureau, from 8: 00 on October, 65438 to 8: 00 on June, this year, the cumulative average rainfall in the whole province was 800 mm, which was more than the average of 708 mm in the same period over the years 13%. According to the latest analysis by the Provincial Hydrographic Bureau, the rainfall this year is slightly 840mm less than that of 1954 and 780mm more than that of 1998, 2.6%.

In general, floods in the middle and lower reaches of the Yangtze River occur earlier than those in the upper reaches, so it is not easy to encounter large-scale floods. In normal years, most regional floods occur in the Yangtze River basin. If the weather is abnormal, the upstream floods are advanced or the floods in the middle and lower reaches are postponed, the bottom water of rivers and lakes is too high, the upstream floods follow one after another, the flood processes overlap, and the main tributaries are repeatedly encountered, resulting in the whole basin floods with high flood peaks, such as 193 1, 1954 and 1998 floods.

Since the flood season this year, the water level in the middle and lower reaches of the Yangtze River has continued to rise. At 8: 00 on June 9, the water levels of Cuntan, Yichang and Chenglingji control stations reached 164.39m, 44.98 m and 30. 10m respectively, in which the water level of Chenglingji station was 2.6 m higher than the average of the same period last year and 5. 13m higher than the same period last year. According to the analysis of the Yangtze River Defense General, the rain and water conditions this year are similar to those of 1998 and 1954.

Many people remember the flood of 1998.

Li Binghui, deputy director of the Hydrology Department of the Provincial Hydrology Bureau, said that from June to March, the rainfall in the middle and lower reaches of the Yangtze River was unusually high. From April to May, there is more rainfall in the upper reaches of the Yangtze River. 1998 flood has the following characteristics.

The flood occurred in a wide range. During the period of 1998, major floods occurred in the middle and upper reaches of the Yangtze River, as well as in the 5 rivers of Poyang Lake and 4 rivers of Dongting Lake. Floods exceeding the measured maximum water level and maximum discharge occurred in several main control stations and tributaries in the middle reaches of the Yangtze River, which is another basin-wide flood after 1954.

The flood came early. 1998 65438+1From October to March, the highest water level occurred in the middle and lower reaches of the Yangtze River in the same period in history, and the peak discharge of Xiangjiang River in Dongting Lake system and Ganjiang River in Poyang Lake system was the largest in mid-March.

There are many flood peaks, and the flood magnitude is large. Eight floods occurred at Yichang Hydrological Station in the upper reaches of the Yangtze River, with peak flow exceeding 50,000 cubic meters per second. The maximum 30-day flood is about once in a hundred years. From June to August, the total flood volume and the maximum 60-day flood volume both exceeded 1.954, and Hankou Station in the middle and lower reaches was close to 1.954.

The flood peak water level is high and the high water level lasts for a long time. The water levels of Shashi-Luoshan and Wuxue-Jiujiang hydrological stations in the middle and lower reaches of the Yangtze River all exceeded the highest water level in history, which was 0.55 to 1.25m higher for more than 40 days. Most areas of Dongting Lake and Poyang Lake water systems also generally exceeded the historical highest water level, and Chenglingji Station and Hukou Station, the control stations of the two lakes, both exceeded the historical highest water level for 29 days.

The flood raged. Floods in the upper, middle and lower reaches of the Yangtze River and floods in Dongting Lake and Poyang Lake occurred on 1998. From mid-June to late July, the floods in the two lakes were superimposed, and the water level in the middle and lower reaches of the Yangtze River continued to be high. In August, there were many floods in the upper reaches of the Yangtze River. In particular, the sixth flood first met with the floods in the Three Gorges area and Qingjiang River, and then with the floods in Yuanjiang River and Lishui River in Dongting Lake. When passing through the Wuhan section, the flood combination is extremely bad when it is superimposed with the Hanjiang flood that arrives at the same time. The floods in the main and tributaries are repeatedly encountered and superimposed, and combined into a multi-peak flood process with high peak and large volume.

"signal gun" in the rain

Correspondent Yang Lifang

Since the beginning of this year, the weather in our province has been extremely complicated and disasters have occurred frequently. There have been geological disasters such as freezing rain and snow, lightning, strong wind, hail, continuous rain in spring, low temperature in May, heavy rain and flash floods. The meteorological department of our province gives full play to the role of "message tree" and "signal gun". Up to now, 59.74 million meteorological warning messages have been sent free of charge.

Hunan is one of the provinces with the most frequent and serious meteorological disasters, especially the flash floods and geological disasters caused by heavy rains. There are 1 1 meteorological satellite ground receiving stations, 7 new generation Doppler weather radars and 301/regional meteorological observation stations in our province. The modern comprehensive meteorological observation network, which is composed of ground and high-altitude meteorological detection network and lightning monitoring network, has improved the monitoring and early warning ability of meteorological disaster prevention in our province.

Since the beginning of this year, the meteorological department has done its best to forecast and warn major weather processes, accurately predicting the low temperature rain and snow freezing at the beginning of the year, the rain concentration period in May and the low temperature in May, and accurately predicting seven large-scale heavy rainfall weather processes. This year, * * * released meteorological forecast service data 139, which played an outpost and staff role for the decision-making of disaster prevention and mitigation of the provincial party Committee and government and the flood control dispatching of the provincial defense index.

In order to improve the ability of meteorological disaster early warning information release, meteorological departments release weather forecast and early warning information through various channels and means with the help of television, internet, radio, newspapers, short messages, Weibo and other media and information platforms. At present, there are 1.7 million users in the province who are responsible for the early warning of meteorological short messages on mobile phones, and a "green channel" for the rapid release of meteorological early warning information on mobile phones has been established and improved. At the same time, the red warning after 22: 00 pm is repeatedly sent to strengthen the reminder.