Frost: Variation Characteristics and Its Influence on Crops in Wuwei
To enhance meteorological service for agriculture and reduce the loss caused by frost, the authors analyzed the characteristic of frost and the probability and impact of frost disasters based on data of frost and growth and yield of crop from 1961 to 2015 in counties (districts) of Wuwei. The results showed that: (1) the first frost date was 17-23 days delayed in Wuwei in recent 55 years, the last frost date was 20-29 days advanced and the frost-free period was prolonged for 39-48 days; the variation coefficient was: frost-free period>last frost date>first frost date; (2) the last frost date was mostly positive anomaly from 1960s to 1990s, while was most negative anomaly in the 21st century; the first frost date and frost-free period were mostly negative anomaly from 1960s to 1990s, and were mostly positive anomaly in the 21st century; the anomaly amplitude was bigger in 1960s and 1970s; (3) concerning the average ground lowest temperature when frost appeared, the probability of serious frost damage was 9％ and 2％ at Minqin and Liangzhou, respectively; the probability of middle frost damage was 7％, 7％ and 2％ at Minqin, Liangzhou and Gulang, respectively; the probability of light frost damage was 84％, 91％ and 98％ at Minqin, Liangzhou and Gulang, respectively; (4) the influence of frost on warm-prefer spring corn was significantly greater than that on spring wheat, and the most sensitive period of spring corn to frost damage was 3-7 leaves stage; when the first frost was earlier, the frost-free period was shorter, spring wheat, spring corn and grain crops were easily harmed by early frost and the influence on yield was obvious; but when the last frost date was later, the crops' probability of suffering late frost hazard risk was increased.
NETL
NSTL
万方数据
维普
