Typhoon route
Take the movement path of typhoons in the western North Pacific as an example. There are generally three movement paths:
Westward type: the typhoon moves westward from the east of the Philippines, passes through the South China Sea, and finally reaches the Landing on Hainan Island in China or northern Vietnam. This route mostly occurs from October to November. 2021 is a typical example.
Landing type: The typhoon moves northwest, passes through the Taiwan Strait, makes landfall along the coasts of Guangdong, Fujian, and Zhejiang, China, and gradually weakens into a low pressure. This type of typhoon has the greatest impact on China. The two typhoons "9015" and "9711" that have had the greatest impact on Jiangsu in recent years are both of this type, and they basically follow this type of path from July to August.
Parabolic type: The typhoon first moves northwest. When it approaches the eastern coastal area of China, it does not make landfall but turns northeastward toward Japan. The path is parabolic. This path mostly occurs between May and May. June and September-November.
After a typhoon forms, it usually moves away from its source and undergoes a process of development, weakening and extinction. A mature typhoon has a circular vortex radius of generally 500km to 1000km and a height of 15km to 20km. The typhoon consists of three parts: the peripheral area, the maximum wind speed area and the typhoon eye.
The wind speed in the outer area increases from outside to inside, with spiral cloud bands and bursts of precipitation; the strongest precipitation occurs in the maximum wind speed area, with an average width of 8km to 19km, and there is a ring between it and the eye of the typhoon Wall of cloud; the eye of a typhoon is located in the center of the typhoon. The most common eye of a typhoon is round or oval in shape, with a diameter ranging from about 10km to 70km, with an average of about 45km. The weather in the eye of a typhoon is windless, less cloudy, dry and warm.
Typhoon disasters
Typhoon disasters are mainly caused before and after the typhoon makes landfall. Direct disasters caused by typhoons are usually caused by strong winds, heavy rains, and storm surges.
Typhoon strong winds and the waves caused by it can throw a 10,000-ton ship into the air and break it, or push the ship inland; it can also damage or even destroy buildings, bridges, vehicles, etc. on land. Especially in areas where buildings are not reinforced, the damage is greater.
Floods caused by typhoons and rainstorms are fierce and destructive, and are the most dangerous disasters. When a typhoon moves toward the land, due to the strong winds and low pressure of the typhoon, the seawater accumulates strongly toward the coast, the tide level rises sharply, and the water waves press toward the coast like mountains. In addition, these disasters caused by typhoons can easily induce secondary disasters such as urban waterlogging, house collapse, flash floods, and mudslides.