What's the amount of snow in Xi 'an? It is best to be specific to kilograms per square meter. urgent ......

200 1- load code for building structures GB50009-standard value of snow load and basic snow pressure (snow load) 2009-06-02 14:29:30 Author: Source: China Construction Network Visits: 1 127 Text size: At present, the revision of basic snow pressure s0 in China is based on the maximum snow pressure or snow depth data of meteorological stations (stations) in 672 locations from the establishment of the station to 1995. According to statistics, the maximum snow pressure once in 50 years, that is, the maximum snow pressure with a recurrence period of 50 years, is obtained, so as to specify the local basic snow pressure.

At present, most meteorological stations in China have collected snow depth data, but the corresponding snow density data is incomplete. In statistics, when there is no parallel observed snow density, the local average density is used to estimate the snow pressure.

The average density of snow in each region is as follows: the average density of northeast and north Xinjiang is150kg/m3; North China and Northwest China take 130kg/m3, of which Qinghai takes120kg/m3; South of Huaihe River and Qinling Mountains generally take 150kg/m3, of which Jiangxi and Zhejiang take 200kg/m3.

The probability distribution of annual maximum snow pressure is generally considered as extreme value type ⅰ, and the specific calculation can be carried out according to the provisions of Appendix D. ..

When compiling the basic snow pressure distribution map of China, the following characteristics should be considered:

(1) Northern Xinjiang is a significant area with high snow pressure in China. Due to the influence of cold and humid airflow invading the Arctic Ocean in winter, the area is rich in snow, and the Altai Mountain, Tianshan Mountain and other mountains can block and lift the airflow, which is more conducive to snowfall.

Coupled with the low temperature, the snow can remain insoluble all winter, and new snow covers the old snow, forming heavy snow pressure. In Altai Mountain area, the snow pressure reaches 1kN/m2.

(2) In Northeast China, due to frequent cyclone activities and the uplifting effect of mountains on airflow, there is much snowfall in winter, and low temperature is more conducive to snow accumulation. Therefore, Daxing 'anling and Changbai Mountains are another Gao Xue pressure area in China.

The snow pressure in northern Heilongjiang Province and eastern Jilin Province can reach more than 0.7kN/m2. However, in western Jilin and northern Liaoning, because they are located in the leeward slope of the southeast Daxing 'anling Mountains, the airflow has a sinking effect, so it is not easy to snow, and there is not much snow, and the snow pressure is only about 0.2kN/m2.

(3) The middle and lower reaches of the Yangtze River and Huaihe River Basin are the Gao Xue pressure areas in southern China. The snowfall in winter in this area is not stable. In some years, there is no snow all winter, while in some years, under certain weather conditions, such as the cold wave heading south, the cold and warm air is deadlocked after reaching this area, and the water vapor is sufficient. When the temperature is low, it snows heavily, and the snow is deep, which also brings snowstorms. 1955 On New Year's Day, heavy snow fell in Jianghuai area, with the depth of snow reaching 5 1cm in Nanjing, 52cm in Zhengyangguan and 40cm in Hefei. 196 1 New Year's Day, heavy snow fell in central Zhejiang, with the snow depth of 55cm in Dongyang and 45cm in Jinhua. The snow depth of 40 ~ 50 cm will also appear in parts of northwestern Jiangxi and Hunan. Therefore, the snow pressure in many places in this area is 0.40 ~ 0.50 kN/m2. But the snow period here is short, ranging from 1 or 2 days to 10 days.

(4) The snow pressure in western Sichuan and northern Yunnan is also high. Because of high altitude, low temperature, high humidity and heavy snowfall, it is not easy to melt. However, there is not much snow in the valleys in this area because of the large drop and relatively low height, coupled with the sinking and warming effect of airflow.

(5) Although the winter temperature is low in most parts of North China and Northwest China, there is insufficient water vapor and less precipitation, and the snow pressure is relatively small, generally 0.2 ~ 0.3 kn/m2. In the northwest arid area, the snow pressure is below 0.2kN/m2. The Yanshan, Taihang and Qilian mountains in this area have a little more snow due to the influence of topography, and the snow pressure can be above 0.3kN/m2.