Distribution of Chilling damages and Hail Disaster in China.
Crops in different growth stages encounter unexpected attacks of low temperature,
causing serious damage to fertility, resulting in disaster and yield reduction.
There are four types in China: 1. Low tide cold damage in winter, the most influential
areas are the northwest pastoral areas and the South China tropical crop areas; 2. low
temperature cold damage in summer; 3. frost damage in spring; 4. frost damage in autumn.
Cold wave chilling injury
The distribution area of low temperature chilling injury in autumn in southern rice
cultivation area (mean temperature < 20 ℃ for the first consecutive 5 days from September to November).
The distribution area of cold injury of crops in Northeast China (the frequency of
cold injury is more than 30%). Distribution area of rubber chilling injury in South
China (annual extreme minimum temperature averaged 0-4 ℃ for many years).
Frost damage in spring and autumn (the temperature below 0 during the overwintering period of crops),
frequent areas of frost damage (the frequency of frost damage is more than 16%), a few
years of frost damage areas (the frequency of frost damage is 8-16%) hail damage, hail
from strong cumulonimbus clouds. Although the duration of hail is not long, it is
destructive when large hail falls. Generally speaking, hail occurs more regularly in
mountainous areas than in flat areas, in the north, in the south, in the mid-latitude
semi-arid areas, in the South and in the northwest desert areas.