typhoon course

Taking the typhoon moving path in the northwest Pacific as an example, there are three moving paths:

Westward: The typhoon moved westward from the east of the Philippines, crossed the South China Sea, and finally landed on Hainan Island in China or northern Vietnam. This route mostly occurs in 10- 1 1 month, and 202 1 year is a typical example.

Landing type: The typhoon moved to the northwest, crossed the Taiwan Province Strait, landed in the coastal areas of Guangdong, Fujian and Zhejiang, and gradually weakened into a low pressure. This typhoon has the greatest impact on China. The two typhoons "90 15" and "97 1 1" which have had the greatest impact on Jiangsu in recent years belong to this type, and the paths from July to August are basically the same.

Parabolic type: the typhoon first moves to the northwest, and when it approaches the eastern coast of China, it turns to the northeast without landing, and turns around Japan. The path is parabolic, mostly occurring in May-June and September-165438+1October.

After the typhoon is formed, it will generally move out of the source and experience the evolution process of development, weakening and extinction. A mature typhoon has a circular vortex radius of 500 km ~ 1000 km and a height of 15 km ~ 20 km. Typhoon consists of three parts: peripheral area, maximum wind speed area and typhoon eye.

The wind speed in the peripheral area increases from outside to inside, with spiral clouds and precipitation; The strongest precipitation occurs in the maximum wind speed area, with an average width of 8 km ~ 19 km, and there is a circular cloud wall between it and the typhoon eye; The typhoon eye is located in the center of the typhoon. The most common typhoon eye is round or oval, ranging in diameter from 10 km to 70 km, with an average of about 45km. The weather in typhoon eye is calm, partly cloudy, dry and warm.

The disaster of typhoon

Typhoon disasters mainly occurred before and after the typhoon landed. The direct disasters caused by typhoons are usually caused by strong winds, heavy rains and storm surges.

Typhoon and strong wind and the waves caused by it can throw a 10,000-ton ship into the air and smash it, or push it inland. It is also enough to destroy or even destroy buildings, bridges and vehicles on land. Especially in areas where buildings are not reinforced, the damage is even greater.

The flood disaster caused by typhoon and rainstorm is fierce and destructive, and it is the most dangerous disaster. When the typhoon moves to land, due to the typhoon's strong wind force and low air pressure, the sea water accumulates strongly in the direction of the coast, the tide level rises sharply, and water waves flood the coast. In addition, these disasters of typhoons are also easy to induce secondary disasters such as urban waterlogging, house collapse, mountain torrents and mudslides.