"How big is this desert?"

Zhang Xingyang put his right hand on his eyebrows and looked into the distance.

Two 5.1 eyes can't see the end of this Gobi Desert.

"48,800 square kilometers."

The middle-aged man standing beside Zhang Xingyang said with a face full of vicissitudes.

"Since my grandfather's generation, we have been controlling sand here, and until now we have only confined the desert to this area."

"What I want to see most in my life is for this desert to be fixed."

The middle-aged man pointed to the towering sand dunes in the distance: "I heard from the older generation that when they first came here, there were not so many mobile sand dunes in the local area. ”

"Later, there were more and more mobile sand dunes, and it became more and more difficult for them to control the sand and control."

Moving sand dunes are caused by the extremely low vegetation cover on the dunes, which causes the dunes to be blown by the wind in windy weather.

Thus constantly moving around the local area.

"It's been 50 years since then."

The middle-aged man said with tears in his eyes.

Zhang Xingyang was also in awe.

A person does not necessarily have 50 years in his life.

And the local sand control people have devoted almost all the time they can work to this desert.

It is also their decades of hard work that has kept this desert from expanding.

The desert is a mobile dune-like desert that moves.

If you move to a place where people have settled, it will be an unprecedented disaster.

"You're all heroes." Zhang Xingyang looked at the other party seriously and said.

The middle-aged man's heart warmed, and he smiled and did not continue to speak.

"What is the annual precipitation in the area?"

Without too many greetings, Zhang Xingyang directly asked about the local meteorological data.

Local weather stations, although there are more specific data.

However, the data on paper does not say anything, and Zhang Xingyang still prefers to talk to the locals.

Because of the data from the weather station, it is likely that it is not very accurate.

"In the past, there was little rainfall, but we were able to bring water back from a reservoir more than 100 kilometers away."

The middle-aged man had a sad face and sold miserably to Zhang Xingyang.

"In the past few years, the water in the reservoir has become less and less, and the water we brought back can only meet the needs of people and animals, and there is no way to plant trees."

If you want to control desertification, you must use vegetation to fix sand.

Whether it's a saxo, a sala, or a poplar tree.

These can fix those moving mobile sand dunes in the local area, and become fixed sand dunes.

It is much easier to fix the sand dunes and then manage them.

And to plant vegetation, you can't do it without water.

Even if the water consumption is very small, it needs a lot of water when planted to ensure a survival rate.

"In previous years, the survival rate of planted trees was still more than 20 percent, but now there is not so much water, and even 5 percent is enough."

The middle-aged man looked at the distance and said helplessly as a piece of Suosuo, which had dried up into dry branches and could be directly used as firewood when uprooted.

Zhang Xingyang also intuitively felt for the first time that it was not easy to plant trees and control desertification in the local area.

The survival rate of less than 5 percent means that even if they plant 10,000 trees, only three or four hundred may survive!

This little tree, let alone fixing a small piece of desert, can't even cure a sand dune.

As for the reason for the decrease in the amount of water in the reservoir, Zhang Xingyang can probably guess it.

In recent years, El Niño has been increasing, and the temperature has been rising.

The eastern region, which already has a lot of precipitation, has experienced even greater precipitation, and many areas have experienced unprecedented heavy rainfall.

In the northwest, the temperature has become colder, and a large amount of water vapor has turned into ice and snow and left on the surface, and there is no large amount of water vapor, and the amount of precipitation has plummeted.

What used to be able to get 30-40 mm of precipitation per year may now be less than 20 mm per year.

As a result, more than 100 kilometers away, there was not enough water in the reservoir to allow them to consume as much on planting trees.

It is necessary to ensure that humanity has sufficient water for its own sake.

"So if there is enough water, can the survival rate of the planted trees increase?"

Zhang Xingyang bent down, gently grabbed a dead shuttle, and pulled it out of the sand with a little force.

A closer look at its roots revealed that there was no feeling of moisture.

Pinch its roots hard, like a match, and simply break it directly.

The middle-aged man was a little puzzled when he saw Zhang Xingyang's measures, but he didn't ask: "If there is enough water, the survival rate of the saplings we planted can reach at least 30 percent." ”

The middle-aged man was still wondering if the other party, who was suspected of being a big leader, wanted to connect them to a local waterway.

"What if it rains within a few days of planting the sapling?"

Zhang Xingyang held the shuttle in one hand, looked at the other party and asked.

"It depends on how much rain it gets." The middle-aged man thought carefully for a moment and then said.

"We've had a heavy rain before, and that time washed away a lot of our grown trees."

In the desert Gobi region, because of the relatively small vegetation, the soil is not able to store a large amount of water.

When it rains heavily, a large amount of water can only form a mighty torrent on the ground.

This is also a wonder in the desert, the Gobi mudslide.

Once formed, not to mention the small trees that have just been planted, even poplar trees that have grown in the desert for hundreds of years, can be directly washed away.

"If it's light rain, it's a little useful."

"The survival rate of saplings can rise by one to two percent, to say the least."

The middle-aged man talked about his experience in the process of planting trees and controlling desertification for decades.

Zhang Xingyang didn't ask about the precipitation again, but raised the dead shuttle tree in his hand: "I want to take this away, is it okay?" ”

Although the middle-aged man still didn't know why, he still nodded:

"Yes, it's useless for us to keep it anyway, at most it will be used as firewood."

Zhang Xingyang walked to the side of the jeep he was sitting in when he came, and said before getting into the car:

"Get ready, it won't be long before there will be the rain you want."

Then he didn't make any more stops, and left the area where the sand control people lived.

A few hours later, hundreds of miles away, artificial rain headquarters.

"The local meteorological conditions do not support the use of traditional artificial rainfall enhancement methods."

Generally speaking, artificial rainfall can only be successful when natural clouds have already begun to rain or are about to rain.

"Now it's raining, and I can't even find two cumulonimbus clouds."

Before Zhang Xingyang entered the tent, he heard everyone arguing very fiercely.

"After three days, there will be artificial rainfall."

When Zhang Xingyang entered the tent, he brought everyone a hot news.

The crowd who had been arguing fiercely was suddenly surprised.

"Judging from the recent weather maps, there are no clouds around that can meet the conditions?"

Someone said in confusion.

Domestic meteorological satellites, after a long period of development, have also been able to monitor global meteorological changes.

They have a computer in their hands that can receive weather data in real time.

"Just because you don't have it now doesn't mean you won't have it in the future."

Zhang Xingyang said indifferently:

"After three days, there will be the clouds you need, and don't ask so much about where the clouds are coming from."

The origin of the clouds is not known to anyone but a very small number of people.

In just a few months, Zhang Xingyang has led the research team to further develop microwave meteorological technology.

The energy level is limited by the microwave transmission power of the satellite and the number of satellites, and it is difficult to increase it by several orders of magnitude in a short period of time.

To the point where it can directly affect the huge energy body of the typhoon.

However, in terms of control accuracy, there has been a great improvement.

In the first previous experiment, a cumulonimbus cloud was successfully created over the South China Sea and successfully transported to Sanya.

The error of the cloud does not exceed 300 meters.

The precipitation error of 300 meters is already a very staggering figure.

Previously, it was difficult to control the precipitation range error within a few hundred meters, even if it was artificial rainfall.

In general, it is very common for there to be a gap of one or two kilometers.

The great success of the first experiment has greatly encouraged everyone in the research and development of microwave meteorology.

The previous Typhoon project was a great success.

But it's as if nuclear power was originally developed for nuclear bombs, but it's the nuclear power plants that benefit most people.

We still hope that this very advanced technology can be applied to the benefit of the public.

And now, they have achieved what they could only achieve in myths and legends and fairy tales in the past.

Humanity itself masters the wind and rain!

The precipitation requirements in the desert Gobi region are still relatively high.

The rain can't be too heavy and not too light.

It's too big, and it will directly destroy the trees they planted before.

It's too small, and it's hard to get the amount of water the trees need to survive.

A suitable range must be reached for the newly planted trees to survive.

"Three days, is it enough time for them to plant a new batch of saplings?"

Zhang Xingyang asked a young man inside the tent.

"It's a good time."

Without thinking, the young man replied, "Three days, the sapling that has just been planted has not yet died, and if it is too long, the sapling that was planted at the beginning may have died." ”

The survival time of the seedlings planted in the area is basically calculated in days.

If you can't carry the first half a month, there is no need to continue watering.

Zhang Xingyang nodded and didn't say anything more.

Straight into a tent where no one else was allowed in.

Began to command microwave meteorological researchers thousands of kilometers away.

"The situation on the ground was complicated, and what we had at the beginning didn't quite apply."

Zhang Xingyang said while thinking about what he had seen and heard in the past few days:

"The cumulonimbus clouds that are brought in must not be too big or too small."

"Let's start with a heavy rain in the reservoir area, and then rain on the edge of the desert."

Zhang Xingyang did not give much guidance to the researchers thousands of miles away.

Just spoke up about the local needs.

"Then we can pull a cumulonimbus cloud from Central China."

A few minutes later, after a closer look, the other party in the video said.

"Central China is about to enter the flood season, and it doesn't matter much if it's a little less at this time."

"After entering the flood season, maybe we will continue to pull the local cloud system."

In fact, this only reduces local precipitation slightly.

This is because the source of the flood season is mainly the confrontation between the cold current from the northwest and the warm current from the southeast coast.

They are still far from affecting these two powerful cold and warm currents.

"You decide for yourself which clouds to pull, and I'll watch locally."

Zhang Xingyang said directly.

That night, the electric satellites in space, which were originally facing the sun, began to adjust their attitude drastically.

Begin to aim your microwave emission angle at Central China.

Start at the height of the clouds, creating enough temperature differences.

The temperature difference is high enough to create an extremely strong gale.

The winds pushed several large clouds towards the northwest region.

Along with this, many areas in central China also experienced strong winds of magnitude 7 or above.

It brings some long-lost coolness to the central China region, which is already suffering from high temperatures and looks like a steamer.

Many families who did not turn on the air conditioner because of power saving, or did not have air conditioning at all, instantly felt the coolness blowing outside the window and spent a more comfortable night.

Clouds move very fast, sometimes reaching thousands of kilometers in a single day or night.

However, the speed of microwave weather traction is slightly slower.

This is also to avoid unnecessary trouble beneath the clouds.

Several clouds, not all of which reach desert areas.

In the Loess Plateau, two cumulonimbus clouds have stayed.

They will bring a hearty rain to the local area, which has not had any rain for nearly two months.

In the end, only a small cumulonimbus cloud reached the northwest desert region.

"I don't know if this cumulonimbus cloud can meet your requirements."

Two days later, in the morning, Zhang Xingyang pointed to the black clouds in the sky and said.

"We just tested it, this cloud is above zero, where did it come from?"

The young man looked at the dark clouds in the sky with some confusion and said.

For most of the clouds, the temperature is below zero.

Because it is difficult for them to store heat in the local area, the temperature of the clouds in the high altitude is below freezing.

In this case, most of the precipitation is hail.

This cloud is a rare warm cloud in the area, and the internal temperature is above zero.

"You just have to say if you can use it."

Zhang Xingyang did not answer the other party's question, but continued to ask.

"It works." The young man said after a moment's pause.

"But we don't have much experience with the rain of this kind of warm cloud."

"The success rate of rain enhancement may be relatively low."

Warm clouds and rain enhancement require the sowing of salt powder, urea and other hygroscopic agents in the clouds.

Cold clouds to increase rain are to sow catalysts such as dry ice and silver iodide in the clouds. (End of chapter)