The Story of a Sandstorm 20, a 200 word essay on the story of a sandstorm

The sandstorm is here again, and the wind blows the long yellow sand from distant Inner Mongolia to Beijing. Dust was flying everywhere in the streets and alleys, and there was a pungent smell in every corner. The smell of sand.

On the street, there were only a handful of pedestrians, and the few people who wrapped their faces tightly in scarves and squinted hurriedly walked in anticipation of returning home quickly.

Seeing this, Sandstorm smiled and said, "Hehe, it's amazing, I'm so happy!" The people here are terrified of me, so this is my place, hahaha. ”

The stinking garbage heap on the side respectfully asked, "Excuse me, can you explain why you have become so powerful?" ”

I owe it to the 'great' human beings that I have become so powerful. Sandstorm said unhurriedly. The garbage heap was confused, and hurriedly asked, "How do you say this?" ”

Sandstorm continued: "It was humans who gave me life, because people cut down trees with impunity, people destroyed biological chains; indiscriminate killing of animals; Wasting water resources and drying up rivers.

This annoyed nature, and it commanded me to "teach" humanity.

The origin of a sandstorm is that a strong wind kicks up loose dust.

Because there is little precipitation in semi-arid and arid areas in winter and spring, the surface is extremely dry and loose, and the resistance to wind erosion is very weak. Strong wind, strong thermal instability, and sand source are the three important conditions for the formation of sandstorms, respectively.

Favorable weather conditions for the generation of high winds or strong winds, favorable distribution of sand and dust sources and favorable air instability conditions are the main reasons for the formation of sand and dust storms or strong sand and dust storms. Strong wind is the driving force of sandstorms, sand and dust sources are the material basis of sandstorms, and unstable thermal conditions are conducive to the increase of wind force and the development of strong residual vertical current, so as to entrain more sand and dust and roll higher.

Under the conditions of extremely favorable large-scale environment, upper-level dry and cold jet stream, strong vertical wind speed, wind direction shear and thermal unstable stratification, the formation and development of small and medium-scale systems near the front area are caused, which aggravates the pressure and temperature gradients before and after the front area, and forms a huge pressure and temperature gradient before and after the front area. Under the combined action of momentum downward transmission and gradient deviation wind, the wind speed near the surface rises sharply, raising surface sand and dust, and forming sandstorms or strong sandstorms.

With the efforts of experts from the Institute of Environment and Engineering of Cold and Arid Regions of the Chinese Academy of Sciences, a simulation experiment of a sand and dust storm wind tunnel specially set up for the vertical start and transmission mechanism of dust substances was successfully completed. Through experiments, experts found that soil wind erosion is the primary link in the occurrence and development of sandstorms. Wind is the most direct driving force of soil, and the nature of air flow, wind speed, and the relevant conditions of wind during soil wind erosion are the most important factors.

In addition, soil moisture content is also one of the important causes of soil wind erosion.

The arrival of sandstorm weather

Medical experts say that sand and dust are the most harmful to the human respiratory system and should not be taken lightly. In particular, the elderly, infants and young children with poor immunity, as well as people with respiratory allergic diseases, should stay indoors with closed doors and windows and stay away from dust sources as much as possible.

Recently, the sandstorm is menacing, and the beautiful hometown of Gansu is also a place where sandstorms are very rampant. Parents and villagers there, facing the loess with their backs to the sky, bravely fought against the harsh natural environment. Although he is not in his hometown, this long yellow sand seems to have drifted to his side.

The smell of dust in the air is annoying. Only if I treat it with a kind of hometown longing, I think it is cute, isn't it my hometown friend who came to visit me? Sandstorms are not terrible, and the hard-working fathers and villagers will never back down.

A small poem, dedicated to those lovely and brave people, laughing in the desert is a little vast!

Spring flowers. Tenacious openness.

Grass on the side of the road. Still bright.

Sunlight. Strive to penetrate the obscure barrier.

Air. With the confusion of the desert smoke.

The wind blows. It's the longing for home.

The wanderer is heartbroken. Looking in the direction of home.

The wheat on the high slopes of the loess is green.

The sea of rape flowers is full of bees and butterflies.

The hard-working man who is lost in the mist.

Never lose sight of the direction of struggle.

It was as if nature had given them no gift to the stool.

But they bravely fought against nature.

The one who greeted the sky with a smile.

It's my lovely father, the old jujube, and the repentant folks.

1. Sandstorms are relentlessly coming. The whole sky was dark and gray. In the courtyard, the rows of large willow trees swayed its strong body, and the branches that had just spit out tender green broke its fragile life.

2. I saw that the blue sky in the distance suddenly appeared a piece of gray, which was constantly extending forward, getting bigger, and wider, blocking the sunlight and covering the sky like a blanket of the night god.

3. There is chaos between heaven and earth, dust, waste paper, and plastic bags flying all over the sky. The small trees on both sides of the road were staggered by the wind, struggling weakly. Pedestrians on the road covered their faces, lowered their heads, and ran home as if fleeing.

4. Seeing the wind coming and the sand swirling, the grass is not savvy for many years.

5. The sky is dark, the sand is flying and the stones are gone, the wind is roaring, the yellow sand and sand and stones are dancing wildly in the cave and the sky is wide, and the truck is deep in the quagmire; In an instant, the sky was filled with miasma, and it fell straight into the world.

6. After dusk, the sky changes greatly, the wind begins to rage, the sunset hides in the west early, the world begins to be gray and gloomy, accompanied by the pungent smell of dust, permeating the outdoor indoors, so that you have nowhere to hide.