江苏省冬小麦春霜冻害发生规律及其气候风险区划

根据江苏省1980-2009年常规气象台站资料和冬小麦生育期观测数据,提出冬小麦春霜冻的致灾指标,同时运用正交经验函数EOF分析和Morlet小波分析方法探讨江苏省冬小麦春霜冻害的时空分布规律,构建冬小麦春霜冻的灾害风险指数,并用该指数分析江苏省冬小麦春霜冻的气候风险区划。结果表明,(1)1980-1987年间江苏省冬小麦春霜冻年总发生站次以6.11站次/a的倾向率呈显著(P=0.0478<0.05)增加趋势,1988-2009年呈明显减小趋势,减幅为0.9站次/a(P=0.0063<0.01);各等级春霜冻害发生站次也表现出相同的变化趋势;(2)江苏全省冬小麦春霜冻害的历年总发生站次有明显的22a、准11a、4a和2a周期;(3)重霜冻发生次数最多的地区是淮北地区的沐阳县,轻、中春霜冻害发生次数最多的地区是苏北沿海的大丰市;(4)冬小麦春霜冻的高度风险区分布在苏北的新沂市、沭阳县、大丰市、如皋市和如东县;中度风险区分布在徐州(新沂除外)、连云港、宿迁(沭阳除外)、淮安、盐城(大丰除外)、扬州(高邮除外)、泰州(兴化除外)和南通(如皋、如东除外)等地区;低度风险区为整个苏南地区和里下河地区的兴化市和高邮市。

Occurrence Pattern on Spring Frost Injury of Winter Wheat in Jiangsu Province and Its Climatic Risk Division

Based on the observed data of conventional meteorological stations and the investigated data of the winter wheat during the different growth periods in Jiangsu province from 1980 to 2009,in this paper,some plaguing indices for the spring frost injury were designed,an empirical orthogonal function（EOF） and a method of wavelet analysis were used to investigate the spatial-temporal distribution of the spring frost injuries in the province and an risk index was suggested to evaluate the climatic risks of the injuries and decide their divisions in the province.The results showed：（1） the annual occurrence frequency of the spring frost injuries of winter wheat in Jiangsu province had been increasing from 1980 to 1987 and it had been decreasing since 1987.In this 30 years,the temporal evolving tendencies of the spring frost injuries in different grades were consistent with the change of the annual occurrence frequency.（2）There were different occurrence cycles of the spring frost injuries such as a obvious cycle of 22 years,11 years definitely,4 years and 2 years.（3） The maximum occurrence frequency area of the heavy spring frost injuries was Shuyang county where situated in the north side of Huaihe river valley,but the largest occurrence frequency area of the middle and light injuries appeared in Dafeng city along the Yellow Sea coast of Jiangsu province.（4） The high risk areas distributed in Xinyi city,Shuyang county,Dafeng city,Rugao city and Rudong county in the northern part of Jiangsu province.The moderate risk regions were Xuzhou region（Xinyi city was excluded）,Lianyungang region,Shuqian region（Shuyang county was excluded）,Huaian region,Yancheng region（Dafeng city was excluded）,Yangzhou region（Gaoyou city was excluded）,Taizhou region（Xinhua city was excluded） and Nantong（Rugao city and Rudong county were excluded）.The low risk areas were the south part of the province and Xinhua city,Gaoyou city of the Lixiahe river region.