Geographical environment of Gulang county

In spring, with the enhancement of solar radiation, the temperature rises gradually, but due to the frequent cold air activities in spring, it is often accompanied by severe weather such as strong wind, sandstorm, cold wave, frost and spring drought. In summer, the temperature is high, the evaporation is large, and there are often severe weather such as drought, local rainstorm or heavy rainstorm and hail.

The main large-scale weather systems affecting Gulang in summer are Qinghai-Tibet high and western Pacific subtropical high. Because this area is located in the northeast of Qinghai-Tibet Plateau, sunny and hot weather often occurs within the control range of Qinghai-Tibet high pressure. When the large and medium-sized high pressure moves to the eastern plateau, it weakens and disappears or merges into the subtropical high in the eastern continent, and the low pressure trough after it often causes regional heavy rain or heavy rain.

In autumn, with the strengthening of cold air in the north, the solar radiation weakens and the temperature drops rapidly. Frost first appeared in Pingchuan in late September. The daily average temperature dropped from about 20℃ in late August to about 10℃ in mid-September. /kloc-The average temperature in October is 8℃ to 9℃ in Pingchuan, about 5℃ in the foothills, and only about 0.5℃ to 2.0℃ in the mountainous areas between 2,700 meters and 3,000 meters above sea level in Central Asia.

In winter, controlled by the high pressure of Mongolian Plateau and the Siberian cold current, the climate is cold and dry, with little rain and snow. The monthly average minimum temperature is below 0℃, with five months in Pingchuan District (June of the first year 1 to March of the second year) and seven months in foothills and middle and low mountains (June of the first year1to April of the second year).

sunlight

The total sunshine hours in Gulang County are 2628.9 hours to 2852.3 hours, and the sunshine percentage is 59 to 64. Sunshine hours and sunshine percentage decrease with the elevation. The annual sunshine hours in the northern and central warm and cool arid areas are 2852.3 hours, and the sunshine percentage is 64%. July has the most sunshine hours, which is 263.4 hours, and the sunshine percentage is 59%. 65438+February is the least, with 209.7 hours and sunshine rate of 7 1%. The sunshine hours in the cold arid area and cold semi-arid area in South China are 2663.3 hours, and the sunshine percentage is 60%. June has the most sunshine hours, 235.8 hours, and the sunshine percentage is 54%. February at least 2 12.9 hours, sunshine percentage 70%.

radiation

The annual total radiation in Gulang County ranges from 128.0 kcal/cm2 to 136. 17 kcal/cm2, in Yuan Zhuangzi, Sichuan, 136. 17 kcal/cm2 and in mountainous areas.

atmospheric pressure

Gulang county is mainly affected by altitude, and the general air pressure decreases with altitude. The average air pressure in this county is about 793.4 hectopascals. The air pressure is the lowest in the mountainous area of Central Asia in the south, and the highest in the desert and plain in the north.

deposit

The average annual precipitation in Gulang County generally increases from north to south with altitude, and the distribution is uneven. Meteorological data show that the average annual precipitation is 306.7 mm, of which the average annual precipitation in Sichuan is about 200 mm; About 300 mm in shallow mountainous area; 350 mm to 450 mm in alpine mountain areas.

evaporate

Gulang county has a large amount of evaporation, and the average annual evaporation in Sichuan is 2807 mm, which is 13.5 times of the total annual precipitation. In a year, the evaporation is the largest from May to July, all above 400 mm, and it is 1777mm in mountainous areas, which is 4.9 times of the precipitation. The maximum evaporation in a year appears in May-June, and the minimum evaporation in June is 65438+ 10.