Record. As of press time, the water level at Xing Zi Station is 7.09 meters, which is the lowest since Poyang Lake was recorded for 37 years. because

This extreme drought will continue, and Jiangxi issued a red warning of low water yesterday morning.

The drought in Jiangxi comes from many factors, such as less precipitation in the early stage, dry precipitation in summer in this province and serious shortage of precipitation in the upper reaches.

Water. Jiangxi is in an awkward geographical position. In summer, it is not affected by typhoons like the coastal areas in East China.

It is difficult to be influenced by the warm and humid water vapor conveyor belt on the west side of subtropical high to form precipitation. Summer precipitation in Jiangxi is generally not very heavy, and most of it is short-lived.

The time is dominated by convective precipitation, and the precipitation in summer is not as stable as that in spring.

However, first, this year's summer precipitation is more heavyweight. This is because the subtropical high is too strong to control most areas south of the Yangtze River, even if it has

Water vapor transport and convection are also difficult to break through the downward flow inside high pressure and develop. For example, Nanchang has only 0. 1mm precipitation, and there is no precipitation so far. As a result, summer precipitation in many areas of Jiangxi, including Hunan, is extremely low, which is matched by continuous sunny and hot weather.

As soon as the sun gets warmer, the water level drops. The continuous rainstorm has hardly alleviated the drought in the land, and excess water has entered the Three Gorges.

In fact, this also makes the dispatching of the Three Gorges very difficult.

If there is more spring ploughing in the coming year, you may not be able to eat, and there will be less water, and the downstream will continue to be dry. At present, there are about 7000 Three Gorges.

Discharge water, but the problem is that this flow can't even stand up the water level in the middle and lower reaches, whether it is Dongting Lake or Wuhan.

The enclosed water level is falling. In fact, the water level in Wuhan Pass fell below 13m this morning, which is the lowest water level in Wuhan Pass since 1996. Unfortunately, I don't want to accept this reality either. In fact, according to multiple numerical predictions.

Second, in the following 1-2 weeks, most of Jiangxi and Hunan have

Effective precipitation may still be very small. This is because after this round of active cold air, the subtropical high will make a comeback and be as stable as Mount Tai.

An autumn tiger process has been brought to the south of the Yangtze River, and a rare high-temperature sunny and hot process in the same period is ready to go. From high latitudes

Looking around, new cold air is also accumulating to the south. Although the process of cold air going south is sometimes accompanied by the rise of cold front.

Water, but also need enough local water vapor, otherwise the dry and cold north wind will directly take away the local water vapor, and it will be cloudy at most.

Although they are different regions, these places have the same name: Poyang Lake.

Usually, these places are covered by a large area of lake water, but now the riverbed is exposed and the land is cracked, resulting in a large area of arid desert.

Some aquatic plants on the shore originally formed grasslands, and people camped and played in the drought.

It's cruel, but it's still fun If we want to say what is the main theme of the climate in southern China now, it must be drought. In particular, the drought in the two lakes and Jiangxi has reached.

To a very serious extent, 95.7% of counties and cities in Jiangxi experienced severe meteorological drought, and the joint operation of reservoirs in the Yangtze River basin was started twice in one month.

Schedule.

Thirdly, the summer precipitation in China is mainly controlled by subtropical high. Generally speaking, the inner area of subtropical high is strongly controlled by downdraft.

Sunny, hot and high temperature, the northern edge of subtropical high is the intersection of cold and warm air, which is prone to heavy precipitation. A few years ago, vice fever

The high pressure and two northward movements controlled the main flood season in South China, South China and North China, as well as the high temperature and summer drought.

The rain belt is just when it is rainy in the south of the Yangtze River, and the main precipitation in the middle and lower reaches of the Yangtze River depends on this time. however

This year's subtropical high is a little different. The opening of autumn rain in West China has obviously alleviated the drought in Sichuan Basin.

However, the rainfall in the middle and lower reaches of the Yangtze River has been relatively slow.

In the past, typhoons in the western Pacific were mainly active, taking away most of the water vapor in the south, and cold air in the north was active, which came over.

Transportation of warm and humid air flow. In this case, droughts in southern China, especially in the two lakes and Jiangxi Province, continue to occur.

Exhibition. In this case, meteorological drought mostly develops into agricultural drought. However, the future situation is still very grim. Subordinate number

It can still be found that there is still no effective precipitation in the middle and lower reaches of the Yangtze River in the next ten days, and the cold air becomes active in the later period.

The movement will become more active, and it will bring water vapor directly to the coast of South China. After that, the precipitation in the two lakes may have to wait until the south in winter.

It's raining in the branch trough.

Four, so far this year, I haven't seen osmanthus, really, I haven't seen it. Before the Mid-Autumn Festival last year, the streets were full of osmanthus fragrance, right? I sleep.

On the eighth floor, as if nothing had happened, you can sometimes smell the fragrance. At this time of the year, I haven't smelled osmanthus.

I don't know if it's because of the high temperature and drought. Apart from the climate, I can't figure out why there is no osmanthus in full bloom in the city, and

It is not a city in Nanchang, and osmanthus flowers have never been opened in other parts of Jiangxi. The subtropical high rapidly extended from north to west, combined with the Iranian high, and was established in southern China.

The strong subtropical high belt made southern China experience the hottest and driest summer in the history of reliable meteorological observation. and

The westerly trough in the north continues to be active, which makes the subtropical high that should have jumped northward for the second time delay and stay in the middle and lower reaches of the Yangtze River, resulting in

There is more precipitation at the edge of subtropical high in Shandong, while the south of the Yangtze River is continuously controlled by subtropical high, keeping sunny and hot.

Faced with such a severe situation, some netizens will ask, can't it be artificially rained?

In fact, artificial rainfall should actually be called artificial precipitation enhancement, which is to artificially supplement some precipitation according to the principle of precipitation formation in nature.

The necessary conditions of water promote the rapid condensation or contact of cloud droplets, which increase into raindrops and fall to the ground. This method is based on different clouds.

The physical characteristics of the layer, choose the right time, use planes and rockets to scatter dry ice, silver iodide, salt powder and other catalysts into the cloud to make the cloud fall.

Water or increase precipitation.

5. Under the condition that the natural cloud has already fallen or is close to falling, the artificial precipitation enhancement method can play a role.

Use. Because of the large natural variability of precipitation, the artificial rainfall increase is small. There should be enough water vapor; Raising the air block, cooling and condensing; There should be more condensation nuclei. And artificial rainfall base

Only the third condition can be added. If the first and second conditions are not met, we can't do artificial rainfall anyway.

Therefore, the artificial rainfall operation can only obtain the required result of increasing water quantity under certain natural cloud conditions, and the technical conditions are not yet available.

Make artificial rainfall.