Three conditions for the formation of rainstorm

The main physical conditions of rainstorm are: 1. Adequate water vapor; 2. Strong and persistent updraft; 3. The atmospheric structure is unstable. The favorable combination of various scales of weather system and underlying surface, especially topography, can produce heavy rain.

torrential rain

According to China's meteorological regulations, heavy rainfall with 24-hour precipitation exceeding 50 mm is called "rainstorm". Due to the different characteristics of precipitation and topography, the standards of rainstorm and flood are different in different places. 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 blocked areas, rainwater can't be discharged quickly, which leads to water accumulation in farmland and supersaturation of soil moisture, which will lead to more geological disasters.

The harm of rainstorm

Rainstorm is one of the main meteorological disasters in China. Long-term rainstorm is easy to produce water accumulation or runoff flooding low-lying areas, resulting in floods. According to the statistics of 1950 ~ 1999, the average flood disaster area in China for many years is 9.424 million hectares, and the affected area of farmland in severe flood years can reach more than130,000 hectares. Rainstorm is a kind of disastrous weather with serious influence.

Continuous rainstorm, heavy rainstorm and extremely heavy rainstorm in a certain area will often lead to flash floods, reservoir dam breaks, rivers flooding, houses being washed away, farmland being flooded, traffic and telecommunications being interrupted, which will bring serious harm to the national economy and people's lives and property. Heavy rain, especially large-scale continuous heavy rain and concentrated heavy rain, not only affects industrial and agricultural production, but also may endanger people's lives and cause serious economic losses.