Definition of rainstorm What is rainstorm?

1, rainstorm refers to rain with strong precipitation intensity, which is often formed in cumulonimbus clouds. According to China's meteorological regulations, heavy rainfall with 24-hour precipitation exceeding 50 mm is called "rainstorm".

2. According to the intensity of precipitation, it is divided into three grades, namely, the 24-hour precipitation of 50-99.9 mm is called "rainstorm", 100-249.9 mm is called "heavy rainstorm", and more than 250 mm is called "extraordinary rainstorm". However, due to the different characteristics of precipitation and topography, the standards of rainstorm and flood are different in different places.

3. In business practice, rainstorm can be divided into local rainstorm, regional rainstorm, large-scale rainstorm and extremely heavy rainstorm according to its occurrence and influence scope. The local rainstorm lasts only a few hours or dozens of hours, generally affecting tens to thousands of square kilometers, causing less harm. However, when the rainfall intensity is particularly high, it will also cause serious casualties and property losses. Generally, the regional rainstorm lasts for 3-7 days, and the affected area can reach more than10-200,000 square kilometers, and the disaster situation is average. However, sometimes due to the particularly strong rainfall intensity, it may cause serious regional rainstorm and flood disasters. The torrential rain lasts the longest, and it is generally a combination of continuous rainstorms in many areas. Rainfall can last intermittently for about 1 ~ 3 months, and the rain belt can last for a long time. Rainstorm is a kind of disastrous weather, which often causes floods and serious soil erosion, leading to major economic losses, such as engineering accidents, dike breaches and crop flooding. Especially for some low-lying and closed terrain areas, rainwater can not be discharged quickly, resulting in farmland water accumulation and soil water supersaturation, which will cause more disasters.