北京地区冬小麦越冬冻害的时空分布与气候风险区划

Spatial-temporal distribution and climatic risk zonation of freeze injury of winter wheat during overwintering stage in Beijing region.

基于1960-2011年北京地区20站逐日气象观测数据和历史冻害资料，利用主成分方法构建了冬小麦冻害指数，同时运用经验正交函数（EOF）、Morlet小波分析和Mann—Kendall突变检验等方法分析了冬小麦冻害的时空分布规律，通过构建综合气候风险指数研究了冬小麦越冬冻害的气候风险区划。结果表明：冻害指数能较好地反映北京地区冬小麦冻害的历史情况，冻害指数越大则冻害程度越重；近52年北京地区冬小麦冻害指数的年际变化呈极显著下降趋势（P〈0．01），但年际波动加大，主周期变化缩短，目前正处于冻害偏多时期；冬小麦越冬冻害的气候风险概率为32．1％-82．8％，其中轻度、中度和重度冻害风险概率的平均值分别为21．5％、17．4％和17．3％；冬小麦越冬冻害的低风险区主要在昌平区，高风险区位于怀柔区东南部、密云县西南部、顺义区东北部和平谷区，其余大部为中风险区。

Based on daily observed data of 20 meteorological stations from 1960 to 2011 and his- torical freeze injury records in Beijing region, freeze injury index （FI） of winter wheat was estab- lished by principal component analysis. Methods of empirical orthogonal function （ EOF）, Morlet wavelet transform analysis and Mann-Kendall test were used to analyze the spatial-temporal distri- bution characteristics of freeze injury to winter wheat during overwintering stage, and the compre- hensive climatic risk index was synthesized to study the climatic risk zonation of freeze injury in the region. Historical freeze injury of winter wheat could be actually characterized by the FI in Beijing region ; the greater the FI was, the more serious freeze injury would occur. In the past 52 years, the trend of annual FI was declined significantly （P〈0.01）, and the variation of annual FI was obviously increased but the main eigenperiod of freeze injury was tended to be shortened. The climatic risk probability of freeze injury ranged from 32.1% to 82.8% in Beijing region, and the probabilities of slight, moderate and severe freeze injury were 21.5% , 17.4% and 17.3%, respectively. The low-risk area of freeze injury was mainly located in Changping dis- trict, while the high-risk areas of freeze injury were mainly located in southeast of Huairou, southwest of Miyun, northeast of Shunyi and Pinggu districts, and the rest of majority areas were moderate-risk zones of freeze injury in wheat production in Beijing region.