中文摘要：

根据作物气候指标距平，利用经验正交函数和小波分析方法，研究了华北地区冬小麦干旱的空间分布和时间演变特征。研究结果表明，主要有3种空间分布类型：以中西部为中心的全区一致型；西北、东南相反分布型，其正值中心分布在北京、霸州等区域，负值中心分布在济南、淄川、临沂等区域；东、西相反分布型，其正值中心分布在河北省东北部的唐山、秦皇岛和山东省的烟台、福山、海阳为等区域，负值中心分布在河北省的邢台、石家庄以及河南省的安阳和新乡等区域；3种空间分布型时间系数变化趋势都表明，20世纪90年代以后华北地区冬小麦干旱呈加重的趋势。，

英文摘要：

Based on crop climate index anomaly data, the spatiotemporal features and changes of drought for winter wheat in north China were analyzed using the empirical orthogonal function（EOF） and wavelet analysis methods. The results show that there are three typical distribution patterns of drought for winter wheat in north China, which are： the ＂all region consistency＂ type centering the west-midst in north China, the ＂northwest-southeast contrary＂ type, with the positive value centering Beijing, Bazhou, et al. and the negative value centering Jinan, Zichuan, Linyi, et al. , and the ＂west-east contrary＂ type with the positive value centering Tangshan , Qinhuangdao in Hebei Province and Yantai, Fushan, Haiyang in Shandong Province, and the negative value centering Xingtai, Shijiangzhuang, Anyang in Hebei Province, and Xinxiang in Henan Province. The analysis of time coefficients of the three spatial distribution modes of drought all show that drought has an increasing tendency since 1990s.