我国冬小麦霜冻灾害致灾因子危险度评价——基于作物生育阶段气象指标

霜冻是一种威胁农业生产的气象灾害,对其致灾因子危险度的研究,可为大尺度的作物霜冻灾害区划及农业保险提供依据。根据作物生长发育的阶段性原理,以全国751个气象台站56年的逐日最低气温资料以及作物生育期资料为基础,统计得到冬小麦各个生育阶段不同灾害等级（轻霜冻、中霜冻、重霜冻）的年霜冻日数,并计算出冬小麦全生育期内不同等级霜冻的发生概率,基于以上两项指标对冬小麦霜冻致灾因子危险度做出评价。结果表明,研究期内重霜冻年霜日最大值为129d,而轻霜冻和中霜冻霜日最大值分别为23 d和19 d,冬小麦受重霜冻危害时间较长;冬小麦霜冻的频发区、多发区、少发区从北向南依次分布,随着霜冻等级增加,频发区的面积差异不大,但多发区的面积减小、少发区面积增大;冬小麦霜冻灾害危险度等级最低的地区主要分布在低纬度的几个省份,如海南、广东、广西、云南等,危险度等级最高的地区集中在青藏高原地区。

Frost Hazard Risk Assessment of Winter Wheat: Based on the Meteorological Indicator at Different Growing Stages

Frost is a meteorological disaster which is a threat to agricultural production. The research on its hazard risk can provide a basis for the large-scale agricultural disasters regionalization and agricultural insurance.According to the theory of crop growing stages, the average annual number of frost days on different degrees (light frost damage, medium frost damage, serious frost damage) in every growing stage of the winter wheat is counted and the probability of the occurrence of frost on different degrees in the whole growth of winter wheat is calculated as well based on the daily minimum temperature data and information about crop growing period of 751 meteorological stations nationwide in the period of 56 years. The winter wheat frost hazard risk degree is assessed based on the above two indicators. The result shows that the serious frost damage frost day is in a maximum of 129 days, and the light and medium frost damage frost day are respectively in a maximum of 23 days and 9 days, so that the winter wheat in China is suffered from serious frost damage for a long time. The probability of the occurrence of frost increases from south to north. With the increase of hazard risk degree, there is bttle different in the area of where there is high-frequency frost. However, the area of where there is frequent frost is decreased, and the area of low-frequency is increased. The lowest degree of frost disaster risk is mainly distributed in low-latitude provinces, such as Hainan, Guangdong, Guangxi, and Yunnan. The highest is mainly distributed in Qinghai-Tibet Plateau.