Wind rating, abbreviated as "wind level", is a representation of wind strength. Wind force refers to the amount of force that the wind shows when it blows onto an object.
Li Chunfeng
Origin of wind rating
The first person to grade wind power was Li Chunfeng, an outstanding astronomer, Yi scholar, mathematician and feng shui scientist of the Tang Dynasty on the mainland.
In the first year of Emperor Taizong's Zhenguan, Li Chunfeng wrote to put forward 18 opinions on the "Pengyin Yuan Calendar", and Emperor Taizong adopted 7 articles, compiled the "Qi De Calendar", was awarded the general Shi Lang, served in the Taishi Bureau for 40 years, and was posthumously awarded the "Taishi Order". Legend has it that the "Push Back Map" is also from his and Yuan Tiangang's hands; the seven volumes of the "Fa Xiang Zhi" he wrote pointed out the difference between the gains and losses of the previous generation of armillary celestial instruments, and Shangshu Taizong suggested that the "armillary celestial sphere" be reformed, and after 7 years of Zhenguan, it was finally made into a "copper building armillary heaven zodiac instrument", changing the ancient two-fold armillary instrument to a triple instrument, the outermost one is the six-fold instrument, the middle is the three-fold instrument, the innermost four-travel instrument, which can determine the latitude and latitude of the ecliptic, the equatorial longitude and latitude, the horizon longitude and latitude, and the Taizong plus the inheritance of the lang.
Zhenguan 15 years official to Taichang Doctor, Zhenguan 18 years official to Taishi Cheng, wrote the "Book of Jin", wrote "Astronomy", "Vinaya", "Five Elements" three zhi, research and summary of the research results of predecessors, made great contributions to the development of traditional culture. In the 22nd year of Zhenguan, he was appointed Taishi Ling, was approved and annotated by the Edict of ten arithmetic, promulgated by the Guozijian, the world's earliest arithmetic textbook, used for many years in Chinese, Japanese, Korean, and Korean schools, and was an important book for the examination of technical officials.
The famous "Zu Hui Principle" for calculating the volume of spheres is Li Chunfeng's commentary on the "Nine Chapters of Arithmetic", which was introduced and spread.
Li Chunfeng's famous book "Yi Wei Zhan" is the earliest monograph in the history of world meteorology, on the basis of the ancient "eight winds", combined with the Bagua Tiangandi branch, he further clarified the wind direction as 24, and created the 8-level wind standard:
Grade 1 moving leaf.
Level 2 tweet.
Level 3 shaker.
Level 4 Fallen Leaves.
5-level folded twigs.
6-level folded branches.
Level 7 folding wood, flying sand stone.
Level 8 uproot trees with roots.
Plus no wind, japanese wind (weak wind) a total of 10 levels.
This kind of experiment conforms to scientific classification, and Li Chunfeng was the first person in the world to grade the wind and made outstanding contributions to world meteorology.
Puff Wind Class
After more than 400 years, the British scholar Bo Fu further divided the wind according to Li Chunfeng's standard of dividing wind power, and set the wind power as 0 to 12 levels for a total of 13 levels. It was first used on the surface of the sea, using the state of the ship and the waves as a reference, and later applied to the land, using smoke, leaves, branches and the swaying of flags as a reference.
Wind level tips:
Zero-level wind, smoke straight up; first-class wind, smoke slightly off;
Secondary wind, the sound of leaves; tertiary wind, flag flying;
Four-level wind, dust up; five-level wind, waves;
Six-level wind, big tree shaking; seven-level wind, difficult to walk;
Eight-level wind, broken branches; nine-level wind, chimney collapse;
Grade 10 wind, tree roots uprooted; level 11, land rare;
Twelve levels, less there; the wind roared, the waves raged.
National standard wind rating
According to the latest national standard of "Wind Rating" released by the mainland in June 2012, according to the wind speed at the height of 10 meters of the standard meteorological observation field, the wind power level is divided into 18 levels in turn, and there are 3 common units of wind speed, namely nautical miles per hour, meter / second, kilometer / hour, and the commonly used units for continental hurricane forecasting are meters per second.
Wind is usually expressed in terms of wind power and wind speed. Wind speed refers to the distance at which the air flow moves per unit of time, and the forward speed of the wind is expressed in meters per second or thousand meters per hour. The greater the air pressure difference between the two adjacent places, the faster the air flow, the greater the wind speed, and the greater the force of the wind. Therefore, the size of the wind is usually expressed in terms of wind force.
Founder of Shuyuan Zhouyi Culture Mr. Shuyuan (Ma Luwei).