Basic knowledge of Qinghai tour guides: plateau climate

(1) Characteristics of Climate Resources Qinghai Province is located in the Qinghai-Tibet Plateau, living inland and far from the ocean, and belongs to the continental climate of the plateau. Climate resources have the following characteristics:

(1) The solar radiation is strong and there is plenty of sunshine. The annual total solar radiation in most parts of Qinghai is higher than 605 kJ/cm2, and that in Qaidam Basin is higher than 700 kJ/cm2. The annual sunshine hours are more than 2,500 hours, and the Qaidam Basin reaches more than 3,500 hours. It is a province with many sunshine hours and large total radiation in China.

(2) The average temperature is low, but it is not particularly cold. The average annual temperature in Qinghai is between -5.7℃ and 8.5℃. Qilian Mountain and Qingnan Plateau with annual average temperature below 0℃ account for more than 2/3 of the whole province, while Huangshui and Yellow River basins in the east have annual average temperatures around 6℃ and 8℃. The average temperature of the hottest month in all parts of the province is between 5.3℃ and 20℃; The average temperature in Leng Yue is-17℃ ~ 5℃. Although the cold period is longer in most parts of the province, it is not too cold in winter.

(3) Less precipitation and large regional differences. The annual precipitation in most parts of China is below 4000mm. Nine branches, Banma and Nangqian on both sides of Daban Mountain and Laji Mountain in the east and in the southeast are all over 60mm, of which nine branches are the most, accounting for 772.8mm. The Qaidam Basin is less than 100 mm, and the northwest basin is less than 20mm, of which the cold lake is only16.9mm.. ..

(4) The rain and heat are in the same period. Qinghai belongs to the monsoon climate zone, and one of its inherent characteristics is the same period of rain and heat. Most parts of Qinghai entered the rainy season after mid-May and ended around mid-September, lasting about 4 months. This period is the duration of monthly average temperature ≥5℃. The period of high temperature in a year is also a period of relatively abundant rain, which is undoubtedly beneficial to the growth and development of crops and pastures.

(5) There are many meteorological disasters with great harm. The main meteorological disasters in Qinghai are drought, hail, frost, snowstorm and strong wind. Among them, droughts are frequent and serious, and the affected area is large, especially in spring, regardless of agricultural and pastoral areas, it is said to be "nine droughts in ten years"; Hail falls frequently and for a long time, which is harmful to agriculture and animal husbandry. Frost, especially early frost in mountainous areas, seriously affects the yield and quality of crops. Snowstorms and blizzards occur from time to time in pastoral areas, which seriously threaten animal husbandry production.

(II) Distribution of Climate Resources Climate resources are closely related to the national economy and human activities, especially to agricultural production, which directly affects the success or failure of agricultural production. The climatic conditions of a region depend not only on the suitability of the quantity of light, heat and water resources, but also on the coordination of the combination and distribution of light, heat and water. 1. The distribution of heat resources is generally characterized by the air temperature level and the accumulated temperature during each boundary temperature period.

(1) Annual average temperature, hottest month average temperature and Leng Yue average temperature. ① Due to the influence of topography, the general distribution trend of annual average temperature is high in the north, low in the south and high in the middle. The low temperature area is: the central and western parts of the southern Qinghai Plateau, most of which are below -3℃, among which Maduo, Qingshuihe, Wudaoliang and Tuotuo River are below -4℃, and Wudaoliang is as low as-5.7℃; The temperature in the northern Qilian Mountains is lower than -2℃ ~-3℃, and that in the eastern Hala Lake is lower than -5.6℃. The relatively high temperature area is distributed in Huangshui in the east, Yellow River Basin and Qaidam Basin in the west. The former is higher than 5℃ and Xunhua can reach 8.5℃; The latter is higher than 3℃, and Chaerhan can reach 5. 1℃. In addition, the annual average temperature in the southern valley of Qinghai-South Plateau is higher than 2℃, of which Nangqian is 3.9℃. (2) July is the warmest month in a year in all parts of China, and the distribution trend of its monthly average temperature is similar to that of the average temperature, but it is much higher in magnitude, with the monthly value ranging from 5℃ to 20℃. Temperatures above 30℃ only appear in the eastern part of Yellow River, Yellow Valley and the western part of Qaidam Basin, and Qarhan reaches 35.5℃. ③65438+ 10 is the coldest month in a year in all parts of the province, with the monthly average temperature ranging from-18℃ to -6℃, and the regional distribution trend is similar to the annual average temperature. The lowest value is below-14℃ in the central and western Qilian Mountains and the central and western Qingnan Plateau. Where Toler is-18. 1℃ and Wudaoliang is-17℃. The extreme minimum temperature below -40℃ only appears in the central and western parts of the southern Qinghai Plateau, and Maduo is the lowest, reaching-48.438 0℃.

(2) Daily temperature range and annual range. Qinghai Province is located in the plateau, with strong solar radiation, strong ground heating during the day and extreme temperature changes in the near-surface layer, so the large daily temperature difference is a major feature of climate resources in most areas of Qinghai Province. The daily range of annual average temperature is above 65438 04℃ in most areas, and above 65438 06℃ in northern Qaidam, Tole River, Babao River and Heihe River basins. Among them, the central and western Qaidam basin is above 17℃, and the cold lake reaches 17.8℃, which is the place where the annual average temperature in the province is getting worse day by day; Donghe River, Huangshui River Basin and the surrounding areas of Qinghai Lake are below 14℃, and Jiangxi ditch is 1 1.5℃, which is the place with the smallest daily average temperature variation in the whole province. Qinghai province is located in the deep inland, far from the ocean, and belongs to an area with obvious continental climate. The temperature should change more violently in a year, but this is not the case. Because the influence of altitude greatly exceeds the influence of latitude, the annual temperature changes slowly, and the annual variation is relatively small. Most areas are below 26℃, of which Banma and Nangqian are below 20℃, which is smaller than those in East China, Central China and North China with similar latitudes. Some areas, such as the semi-desert landscape in Qaidam Basin, have clear and cloudless weather, strong solar radiation, little precipitation, very dry surface and high temperature in summer.

(3) Accumulated temperature during each boundary temperature. The intermediate temperature of agriculture and animal husbandry production in Qinghai Province is: 0℃, the soil thaws, the grass begins to sprout, all kinds of crops begin to sow, and the farming season begins; 3℃, indicating that the perennial grass turns green and the grass growth period begins; 5℃, indicating that most trees began to grow, and general grasses began to grow vigorously; 10℃, indicating that crops began to enter a vigorous growth period. The regional distribution trend of accumulated temperature (active accumulated temperature) at each boundary temperature in Qinghai Province is roughly the same as the annual average temperature, that is, it is more frequent in the east and Qaidam Basin, and decreases rapidly with the elevation.

(4) daytime temperature. Qinghai province has a large daily temperature difference, with high temperature during the day and low temperature at night. In some areas, the average temperature and accumulated temperature are low, but due to the high temperature during the day, some planting can still be developed. The average daytime temperature in March ~165438+10 is higher than the annual average temperature 1℃ ~ 4℃. Among them, the average temperature in Qaidam Basin, around Qinghai Lake and east Qilian Mountain is about 3℃ higher. The height of Hehuang River basin and Hainan platform in the east is1℃ ~ 2℃; Other areas are 2℃ ~ 3℃ higher.

(5) Frost-free period. The frost-free period of Donghe and Huanggu Valley begins before the end of April and ends after mid-January of Io. Frost-free period 150 days or more, of which Xunhua, Jianzha and Minhe are 180 days or more, which is the longest frost-free period in the province. Most of Qaidam basin, Hainan platform and mountainous areas of Donghe and Huangshui basins start from late May to early June and end in the middle and late September, and the frost-free period exceeds 100 days. Among them, Golmud and Xiangride reached 125 days or so; The frost-free period in southern Hainan is less than 60 days, and that in Tongde is only 3 1 day. The frost-free period in the southern part of Qingnan Plateau and the eastern part of Qilian Mountains is between 50 days and 100 days. The frost-free period is generally shorter than 40 days in most parts of southern Qinghai Plateau and central and western Qilian Mountains from mid-July to mid-August. Qingshuihe, Wudaoliang and Zeku are only about 10 days, which is the shortest frost-free period in the province.