What are the climatic characteristics of plateau natural environment?

Atmospheric pressure varies with altitude, so does the partial pressure of various gases that make up the atmosphere, that is, it decreases with the increase of altitude. So is the partial pressure of oxygen. The atmospheric pressure in the plateau area is reduced. When the oxygen content and oxygen partial pressure in the atmosphere decrease, the oxygen partial pressure in human alveoli will also decrease, the oxygen diffused into the blood of pulmonary capillaries will decrease, and the arterial oxygen partial pressure and saturation will also decrease. When the oxygen saturation is reduced to a certain extent, it will cause insufficient oxygen supply to various organs and tissues, and there will be functional or organic changes, and then there will be symptoms of hypoxia, such as headache, dizziness, memory loss, palpitation, shortness of breath, cyanosis, nausea, vomiting and so on. This is also the root cause of various altitude sickness.

Second, it is cold and dry.

With the increase of altitude, the temperature gradually decreases. Generally speaking, the temperature drops by about 1℃ every altitude1000m. In some areas, it can even drop 1℃ every rise150m. In most parts of the plateau, the air is thin and dry, and some areas are cloudy. During the day, the ground receives a lot of solar radiation energy, and the temperature near the ground rises rapidly. At night, the ground heat dissipation is very fast, and the ground temperature drops sharply. So there is a big difference between the highest temperature and the lowest temperature in a day on the plateau. Sometimes, during the day, it is cold and hot, and the sun is shining in the sky during the day. Sometimes the temperature is as high as 20~30℃, and sometimes it can drop below 0℃ at night and in the morning, which is also a major feature of the plateau climate.

Because the plateau atmosphere is depressed, the water vapor pressure is also low, and the moisture in the air decreases with the increase of altitude, so the higher the altitude, the drier the climate. The wind speed in the plateau is high, and the water loss on the body surface is obviously higher than that in the plain, especially when working or strenuous activities, breathing deepens and sweating water is released. At the same time, due to the influence of diuresis factors such as altitude hypoxia and cold, the body's water content is reduced, which leads to abnormal dryness of respiratory mucosa and whole body skin, decreased defense ability, and prone to symptoms such as pharyngitis, dry cough, nosebleeds, chapped hands and feet.

Third, long sunshine time and strong solar radiation.

The plateau air is thin and clean, with less dust and water vapor content, and the atmospheric transparency is higher than that of the plain. The transmittance of solar radiation increases with the increase of height. The main effects of strong ultraviolet rays and solar radiation are that exposed skin and eyes are easily damaged, and skin damage is manifested as sunburn, edema, pigmentation, skin thickening and wrinkles. The intense ultraviolet radiation in the sunshine in plateau area is easy to cause acute eye injury, mainly causing acute keratitis, cataract, visual impairment and snow blindness.

Fourth, other factors.

Hypoxia at high altitude often leads to weakened gastrointestinal peristalsis, decreased secretion of saliva, intestinal juice and bile, loss of appetite and indigestion.