关键词: 双季早稻, 倒春寒, 大气环流, 金衢盆地

Abstract:

According to the national standard（GB/T 34816-2017） for the meteorological indicators of late spring cold, using the historical temperature data of major cities in the Jinqu basin, sort out the cases of late spring cold from 1981 to 2020 and calculate the K value of the meteorological index for each late spring cold. The statistical analysis method and wavelet analysis method were used to analyze the frequency and intensity change characteristics of late spring cold in the Jinqu basin and the atmospheric circulation background. The results showed that the late spring cold in the Jinqu basin occurred frequently in the past 40 years, but the mild late spring cold accounted for a large proportion, and the severe late spring cold only accounted for 3.4%. The index K of late spring cold showed a significant wave dynamic trend, and the K value fluctuated around 3. There were obvious interannual and interdecadal cycle changes of late spring cold number and meteorological index K of 3 a, 7 a, 19 a and 4 a, 8 a, and 20 a in Quzhou. The strong late spring cold was affected by the strong cold air moving eastward and southwards in the Baikal region. The cold advection after the trough continues to infiltrate the south of the Jiangnan region, resulting in an abnormal temperature drop in the Jinqu basin and a severe late spring cold weather disaster.

Key words: double-cropping early rice, late spring cold, atmospheric circulation, Jinqu basin