The second solar term of autumn has just passed, and Huaxi Qiuyu can't wait to go online, and it is a strong attack.

In the past day, there have been heavy rains or heavy rains from West China to Huanghuai, among which heavy rains fell locally in Chengdu, Sichuan.

  The Central Meteorological Observatory issued a blue rainstorm warning at 6 a.m. on the 29th. It is expected that from the 29th to the 31st, there will still be frequent rainfall in Sichuan, Shaanxi and other places, and there will be local strong convective weather such as thunderstorms and strong winds.

At 6 o'clock on the evening of the 28th, the National Defense Directorate launched the four-level emergency response to flood control in Sichuan and Chongqing, and urged the local area to strictly prevent the sudden turn of drought and flood.

  For regions such as Sichuan and Chongqing that suffered from drought in the early stage, what secondary disasters are easily caused by "drastic changes in droughts and floods"?

What are the characteristics of this round of rainfall in the Sichuan-Chongqing region that need to be vigilant?

To strictly prevent the "drastic turn of drought and flood", how should the local response measures be "suddenly turned"?

Heavy rainfall caused dangerous provincial roads to collapse in some townships

  Beginning at 8 p.m. on the 28th, heavy rains and local heavy rains fell in Wangcang County, Guangyuan City, Sichuan, causing some roads to collapse and bridges to appear dangerous.

  Affected by the heavy rainfall, at around 10:20 am on August 29, at Crystal Dam, Gaoyang Town, Wangcang County, Guangyuan, Sichuan Province, a landslide occurred on Line 303 of Provincial Highway, and the collapsed gravel blocked the road and caused traffic interruption.

It is understood that some gravel weighs nearly seven or eight tons.

The local highway department immediately mobilized a large loader to the scene for emergency rescue.

At present, the landslide section has been restored to traffic.

  The heavy rain also caused the water level of some rivers in Wangcang County to rise significantly, and some roads and bridges were in danger. The local party members and cadres organized 24-hour monitoring and inspections.

Zhao Guorui, director of the Emergency Office of Huangyang Town, Wangcang County, Guangyuan City, Sichuan Province:

dispatched a working group to conduct rain inspections on geological disaster sites, mountain ponds, reservoirs and Manshui bridges, and cordoned off key dangerous areas.

  As of 3 p.m. on August 29, local rainfall has weakened.

The rainfall has changed from "significantly less" to "40% to 1 times more"

  According to the meteorological forecast, in the next ten days, there will be continuous rainy weather in West China, with more rainy days, and the accumulated rainfall will be 40 to 1 times more than the same period of the normal year, and 2 times more local. Above, there is the possibility of a sudden turn of drought and flood.

  The so-called sudden change of drought and flood refers to the hydrometeorological phenomenon of continuous drought in the early stage, followed by heavy rainfall in a short period of time, resulting in floods.

Since July, most parts of the four provinces of Shaanxi, Gansu, Sichuan, and Chongqing have continued to be hot and dry, and the soil has lost water and loosened or agglomerated and hardened, and the risk of disasters caused by heavy rainfall has increased.

What secondary disasters are easily caused by "drastic changes in droughts and floods"?

Why does heavy rainfall after a drought increase the risk of disasters?

Fu Jiaolan, chief forecaster of the Central Meteorological Observatory:

In this case, it is easy to form such secondary disasters as flash floods, mudslides, and landslides. At the same time, it is possible that the river water level in such small watersheds will suddenly increase, which may catch people off guard.

The sudden change of drought and flood depends on where the drought mainly occurred in the early stage. If the precipitation happens to be stronger in the dry area, and then occurs in the mountainous area, the risk will be higher.

Tan Wei, a third-level researcher of the Flood Control and Drought Relief Department of the Ministry of Emergency Management: A

long-term drought will have many impacts, especially the vegetation, regulation and storage, and rainwater infiltration in the basin, which are the conditions for runoff and confluence.

Moreover, from the perspective of meteorological statistics, extreme climatic conditions will cause extreme meteorological changes. Rain occurs after a long-term drought, and the rainfall intensity is often larger. That is to say, under the same total rainfall conditions, the changes will be more severe. , it shows that the flood will come faster and more violently, and the disaster will be greater.

  In addition, experts reminded that long-term drought will bring people's psychological expectations of longing for rain and water, and people will have paralyzed thoughts about heavy rain and floods, especially ignoring the dangers of flash floods, which need to be paid special attention and overcome.

There are many autumn rainy days in Western China, and the "continuous drizzle" has hidden destructive power

  One of the most important characteristics of autumn rain in Western China is that it has many days and a long period of rainfall, about 30 to 50 days, and even close to 60 days in some areas.

Most of the time, Qiu Yu's face is "drizzle", but it is not always so gentle, and there will be heavy rains and heavy rains from time to time.

Moreover, most of the rainfall time is at night, and the nighttime rainfall in Guiyang and Chongqing accounts for more than 60%.

  After the previous drought, which type of autumn rain should be especially vigilant?

In what areas should we strengthen our response?

Be alert to the disaster risk of persistent precipitation and local strong convection

  Meteorological experts reminded that during this round of rainfall, two types of precipitation need to be focused on.

One is persistent precipitation under the influence of low eddy.

The slow moving speed of the low vortex leads to a long duration of rainfall. This kind of precipitation is often a convective weather with a weak mixture of stable precipitation. Although the hourly rainfall intensity is not extreme, the duration is relatively long and the accumulated rainfall is large.

The other is local strong convection in the initial stage of rainfall.

The continuous high temperature under the control area of ​​the subtropical high pressure in the early stage has accumulated a certain amount of unstable energy in the atmosphere. Once convection occurs, it will develop rapidly. Such convection precipitation has high efficiency and strong hourly rain, which can easily lead to local sudden short-term fluctuations. Heavy rainfall.

Tan Wei, a third-level researcher of the Flood Control and Drought Relief Department of the Ministry of Emergency Management:

To prevent the sudden turn of drought and flood, we must first pay close attention to the weather situation, conduct rolling consultations to study and judge risks; strengthen short-term forecasting and early warning of disasters, and do a good job in early warning. For people in hilly areas, near rivers, near mountain torrents and remote areas, the "last mile" early warning should be in place, and people in dangerous areas should be transferred in time to avoid casualties. The fourth is to scientifically dispatch flood control projects, and make full use of rain and flood resources on the premise of ensuring flood control safety.

Nearly 120,000 people were transferred from flood control emergency response in many places in Sichuan

  To prevent the sudden turn of drought and flood, Sichuan has also made adequate preparations.

As of the morning of the 29th, 8 cities (prefectures) and 54 counties (cities, districts) in Sichuan issued rainstorm warnings, and 2 cities (prefectures) and 16 counties (cities, districts) launched emergency response to flood control.

  According to preliminary statistics, a total of more than 119,000 people were transferred to safety in advance in Sichuan province.

For construction sites, coal mines and other risk-prone places, Sichuan Province has urged and guided 60 coal mines and 264 non-coal mines to withdraw a total of more than 5,000 people, and dispatched 7 construction sites, Hexinzhou Island and coal mines by telephone. Subsequent follow-up and verification were carried out on the transmission of early warning information and the implementation of withdrawal measures.

  What new measures should be added to the general precautionary measures in the past in order to cope with the disasters that may be brought about by the sudden turn of drought and flood?

Zhu Yaqin, Director of the Flood and Drought Disaster Rescue Department of the Sichuan Provincial Emergency Management Department:

According to the dispatching arrangements of the provincial prevention and control index, 7 emergency rescue teams with more than 260 people are set up in key areas to carry out special dispatching of flood control and disaster reduction, and send the information to the municipal prevention and control offices within the early warning range. Relevant provincial units and emergency rescue teams sent risk alerts, dispatched additional emergency personnel, and through the information system, inquired about the trend of rainwater floods and rainstorm warning and forecast information in various places, and rolled out random inspections of district and county prevention offices, townships, and enterprises to prevent sudden changes in drought and floods. In response to the implementation of the measures, at the same time, a working group was dispatched to the rainy area to supervise and guide the personnel to move ahead to avoid danger, and to link early warning and response.

At the same time, strengthen the connection with the emergency rescue team of the central enterprises stationed in Sichuan, and make every effort to ensure the safety of people's lives and property.