Definition of short-term heavy rainfall

Short-term heavy precipitation is defined as follows:

Short-term heavy rainfall means that the rainfall in a certain place exceeds 20 mm within 1 hour. Short-term heavy precipitation is a strong convective weather. In summer, due to the high temperature and large evaporation, a large amount of water vapor rises and condenses into clouds; At the same time, the cold air in the upper layer will drop, and they will continue to rise after being heated, so as to circulate and form a large cumulonimbus cloud.

Cumulonimbus clouds will produce short-term heavy precipitation (convective rain), sometimes accompanied by strong winds, thunderstorms, hail and even tornadoes and other bad weather. This kind of weather usually lasts for a short time and will clear up soon. It usually appears in the summer afternoon in the northern region.

Short-term heavy precipitation refers to a relatively large precipitation intensity in a short time, and the precipitation is higher than a certain measured value. The regulation of this value varies from place to place. Generally, the rainfall per hour is ≥ 20mm. Short-term heavy precipitation often causes meteorological disasters such as urban waterlogging and landslides, which seriously affects urban operation and even threatens life.

If you walk in outdoor stagnant water, you should pay attention to observation and walk as close as possible to the building to prevent you from falling into the manhole. When you are driving on the road or under the overpass, the water is too deep, so you should try to bypass and avoid forced passage; When the car stalls in a low-lying water area, the people on board must not stay in the car, but should get off and wait for rescue at a high place.

The influence of heavy precipitation

Agriculture is one of the most seriously affected industries. The heavy rainfall caused the farmland to be flooded and many crops were seriously damaged. Especially in vegetable growing areas, the fruits of farmers' labor were washed away overnight by floods, which brought serious economic losses to farmers. In addition, farmland flooding may also lead to the breeding of crop diseases and insect pests, further affecting the yield and quality of crops.

Secondly, traffic is also one of the affected areas. Flash floods and accumulated water caused by heavy rainfall bring great inconvenience to traffic. Many roads were flooded, causing traffic disruption and people stranded.

Especially in mountainous areas and rural areas, because of the fragile infrastructure, the phenomenon that roads are washed away by flash floods is more serious. Traffic disruption in disaster areas not only brings difficulties to rescue and material transportation in disaster areas, but also has a great impact on the lives and work of local residents.