1961-2013年东北三省玉米低温冷害频率的时空动态研究

基于东北三省1961-2013年气象数据，结合具有生物学意义的热量指数，利用SPSS聚类分析方法给出了东北三省低温冷害分类标准，并对低温冷害频率时空特征和年代际空间变化规律进行了分析。研究指出：东北三省玉米（轻、中、重度）低温冷害发生范围随时间呈减小-增大-减小变化趋势，1999年后东北三省出现低温冷害的范围显著减小，变化幅度均为中度> 重度> 轻度低温冷害。近10 a东北三省的轻度低温冷害仍时有发生，而中度和重度低温冷害发生较少。东北三省低温冷害频率呈由北向南呈减小趋势，轻、中、重度低温冷害频率高值区分别位于营口、哈尔滨和大兴安岭地区。各年代的重度低温冷害发生范围变化不大，中度与轻度低温冷害发生范围变化较大。研究结果可为东北三省低温冷害风险评估提供依据。

Temporal-spatial dynamics of maize chilling damage frequency in Northeast China during 1961-2013

Based on the meteorological data of Northeast China during 1961-2013, combined with the biology-based thermal index and SPSS cluster analysis method, the classification of maize chilling damage in Northeast China were established and the temporal-spatial dynamics of maize chilling damage frequency were analyzed. The results indicated that the frequency of different maize chilling damages (mild, moderate, severe) in Northeast China presented a time-dependent reduced-enhanced-reduced trend, and has reduced significantly since 1999. The decreased amplitude of chilling damage frequency was ranged as moderate> severe> mild chilling damage. The mild chilling damage occurred occasionally during recent 10 years, while the moderate and severe chilling damages seldom occurred in Northeast China. The chilling damage frequency decreased from north to south in the three provinces of northeast China, and the high frequency areas of mild, moderate and severe chilling damages were located at Yingkou, Harbin and Daxinganling districts, respectively. The occurrence area of decadal severe chilling damage changed less than those of decadal moderate and mild chilling damages. The results will provide scientific reference for maize chilling damage risk assessment and policy-makers.