Wuyishan City, Fujian Province issued a yellow warning of strong wind. How are the levels of strong winds classified?

? Wind refers to the force generated when the wind blows an object towards it. Usually, according to various phenomena caused by objects on the ground or on the water, the air volume is divided into 13, with the lowest being 0 and the highest being 12. According to the national standard "Wind Energy Grade" issued by the State in June 20 12, and according to the wind speed of the standard meteorological observation site 10 meter, the wind energy grade is divided into 18 grades. There are three commonly used units to express wind speed, namely nautical mile/hour, meter/second and kilometer/hour. Typhoon forecast in China is based on meter/second.

? From 200 1, China Meteorological Bureau issued Regulations on Typhoon Operation and Service, which raised Beaufort's wind force level to above 12 typhoon 17. /typhoon kloc-0/2, set at 32.4-36.9 m/s; 37.0-4 1.4m/s； 14-41.5-46.1m/s; 15 -46.2-50.9 m/s; 16 is 51.0-56.0m/s, and 17 is 56.1-56.0m/s ... 30 years ago, the maximum wind force of typhoon near Qionghai Center reached 73m/s, exceeding the highest standard 17. This is called 18, which is also the general name of super typhoon in the international maritime community.

? Go out as little as possible, ride less bicycles when going out, and don't stay under billboards and temporary buildings to avoid the wind. If you are driving, you should drive into an underground parking lot or a bomb shelter. If you live in a tent, you should immediately put away your tent and take shelter from the wind in a strong house. When working or swimming on the water, you should immediately go ashore to avoid the wind. The ship must obey the command and return to Hong Kong for shelter. Sailing boats should put down their sails as soon as possible. Close the window of the room carefully. Rice belt? Stick it on the window glass to prevent the glass from breaking, and stay away from the window, so as to avoid the strong wind blowing over the sand and breaking the glass and hurting people. In public places, you must evacuate to the designated place. Agricultural production facilities should be strengthened in time, and mature crops should be harvested as soon as possible.