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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MannKendall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 the daily meteorological observation data and historical frost damage data of 20 stations in Beijing area from 1960 to 2011, the freezing damage index of winter wheat was constructed by using the principal component method. At the same time, winter wheat was analyzed using empirical orthogonal function (EOF), Morlet wavelet analysis and Mann-Kendall mutation test, The spatial and temporal distribution of frostbite was analyzed to study the climate risk zoning of winter wheat overwintering frost damage by constructing comprehensive climate risk index. The results showed that the frost damage index could well reflect the history of winter wheat frost damage in Beijing, and the more the frost damage index was, the heavier the frost damage degree. The interannual variation of frostbite index of winter wheat showed a very significant decrease (P <0.01) in recent 52 years. , But the interannual fluctuation has increased and the main period change has shortened. At present, it is in the period of excessive frost damage. The climate risk probability of winter wheat overwintering frost damage is 32.1% ~ 82.8%, and the average of the risk probability of mild, moderate and severe frost damage respectively 21.5%, 17.4% and 17.3% respectively. The low-risk areas for winter wheat frost damage were mainly in Changping District, high-risk areas were located in southeast of Huairou District, southwest of Miyun County, northeast of Shunyi District and Pinggu District, Area.