乐平市晚稻寒露风灾害风险区划

利用景德镇市气象局观测站、乐平市气象局观测站和气象哨所1958～2010年的观测资料，分析了乐平市9月11日～10月10日期间日平均气温≤22℃持续3d或日平均气温≤22℃持续2d且其中1d最低气温≤16℃，日平均气温≤20℃持续3d或日平均气温≤20℃持续2d且其中1d最低气温≤16℃的发生情况；并以稳定通过22℃的终日作为轻度寒露风的标准、稳定通过20℃的终日作为重度寒露风的标准，统计出现频率为10％（10a一遇）、20％（5a一遇）、25％（4a一遇）、33％（3a一遇）、50％（2a一遇）、66％（3a二遇）、75％（4a三遇）、80％（5a四遇）、95％（1a一遇）的日期，以及这些日期随海拔高度的变化情况；最后利用ARCGIS软件，采用1：250000的地理数据，对乐平市晚稻轻度和重度寒露风进行了风险区划。结果表明：乐平市大部分地区轻度寒露风发生的频率为2a一遇，重度寒露风发生的频率为5a一遇；洪岩镇、涌山镇、塔前镇、双田镇、高家镇、众埠镇、名口镇、十里岗乡、礼林镇等地海拔为100rn的山区轻度寒露风发生的频率为3a二遇，重度寒露风为3a一遇；海拔为200m的山区轻度寒露风发生的频率为4a三遇，重度寒露风为2a一遇；在海拔为300m的山区轻度寒露风发生的频率为4a三遏，重度寒露风为3a二遇；在海拔〉400m山区轻度、重度寒露风发生的频率均较高，不适宜晚稻种植。在农业生产上，要科学运用寒露风预测，合理安排生产；同时选育抗低温高产晚稻品种，加强田间管理，改善农田小气候来防御寒露风为害。

Risk Regionalization of Cold Dew Wind Disaster for Late Rice in Leping

Based on the meteorological observation data in Jingdezhen and Leping from 1958 to 2010,we analyzed the occurrence of the daily mean temperature ≤22 ℃ lasting 3 days,or the daily mean temperature ≤22 ℃ lasting 2 days and the minimum temperature ≤16 ℃,and the daily mean temperature ≤20 ℃ lasting 3 days or the daily mean temperature ≤20 ℃ lasting 2 days and the minimum temperature ≤16 ℃ from September 11 to October 10.By using the final date when the temperature steadily passed 22 ℃ as the standard of light cold dew wind,and the final date when the temperature steadily passed 20 ℃ as the standard of heavy cold dew wind,some dates including the frequencies that reached 10%(once every 10 years),20%(once every 5 years),25%(once every 4 years),33%(once every 3 years),50%(once every 2 years),66%(twice every 3 years),75%(three times every 3 years),80%(four times every 5 years),and 95%(once every year)were analyzed,as well as their variation with altitudes.Using ARCGIS and 1: 250 000 geography data,the risk of cold dew wind disaster in Leping was regionalized.The results showed that the light cold dew wind occurred every 2 year in most areas of Leping,while the heavy one occurred every 5 year.The light cold dew wind occurred twice every 3 year,and the heavy one occurred every 3 years in hilly areas with the altitude above 100 m,such as Hongyan Town,Yongshan Town,Taqian Town,Shuangtian Town,Gaojia Town,Zhongbu Town,Mingkou Town,Shiligang Town and Lilin Town.In hilly areas with the altitude above 200 m,the light cold dew wind occurred 3 times every 4 years,and the heavy one occurred every 2 year.In hilly areas with the altitude above 300 m,the light cold dew wind occurred 3 times every 4 years,and the heavy one occurred twice every 3 year.In hilly areawith the altitude above 400 m,the frequency of heavy cold dew wind was so high that late rice was not appropriate to grow.The cold dew wind disaster could be defended by predicting the disaster scientifically,planning production reasonably,breeding low resistant and high yield late rice varieties,and strengthening field management.