2020年我国南方双季晚稻寒露风危害的变化特征

Variation Characteristics of Chilling Dew Wind for Double-Season Late Rice Across Southern China in 2020

基于高分辨率的土地利用/土地覆被遥感监测数据,融合下垫面信息、格点化寒露风等级和不同尺度寒露风指数,分析了2020年我国南方双季晚稻区的寒露风特点。结果表明:2020年晚稻寒露风发生时间早,持续时间长,普遍出现轻度至重度寒露风。寒露风发生面积占稻田总面积的24.7%,为2000年以来第三高,发生轻度、中度、重度寒露风的面积比例分别为9.7%、12.8%和4.9%;湖南、江西、浙江发生面积比例超过90.0%,其余省(自治区)不足30.0%;2020年湖南、湖北、安徽、江苏发生面积比例为2000年以来最高,江西发生重度寒露风面积比例为2000年以来最高,浙江、福建、广西发生寒露风以轻度为主,广东寒露风发生面积较小;晚稻区寒露风指数达4.21,为2000年以来第二高;2020年湖南、江西、湖北寒露风指数较高,分别达7.16、7.16、12.59,相应分别为2000年以来第二高、最高、最高。

Based on land use/cover change dataset at a resolution of 30 m×30 m,the characteristics of chilling dew wind in 2020 are analyzed for double-season late rice by using the information of underlying surface,gridded monitoring degree and chilling dew wind index.It is shown that the chilling dew wind in 2020 is characterized by earlier start date,longer duration and general low-to-heavy degree occurrence across double-season rice area.There is 24.7%of late rice area exposed to chilling dew wind,which is the third largest since 2000.The area percentages of low,medium and heavy chilling dew winds are 9.7%,12.8%and 4.9%,respectively.In terms of the statistic in provinces,it is obvious that the area percentage of late rice area affected by chilling dew wind is more than 90%in Hunan,Jiangxi and Zhejiang,but is less than 30%in other provinces.The area percentage subjected to chilling dew wind in Hunan,Hubei,Anhui and Jiangsu is the largest since 2020,and Jiangxi has the largest area percentage of heavy chilling dew wind since 2000.The light degree of chilling dew wind occurs in Zhejiang,Fujian and Guangxi,and the occurrence area of chilling dew wind in Guangdong is small.The integrated index for chilling dew wind in double-season late rice area is 4.21 in 2020,which is the second largest since 2000.Moreover,the indexes in Hunan,Jiangxi and Hubei reach 7.16,7.16 and 12.59,which is the second largest,the largest and the largest since 2000,respectively.