摘要
从山西省阳城县1957-2013年春季晚霜冻出现日期中找出最晚出现日期作为0点,求出各晚霜冻日期与0点的相对日期,将灾变点的相对日期确定为灾变阈值。绘制相对日期年际变化曲线和阈值水平线,把二者第二个交点及之后各交点分别到第一个交点的间距作为灰色GM(1,1)模型建模的原始数据序列,从而建立GM(1,1)传统模型,利用优化序列、优化背景值和灰数等维递补方法逐步改进模型,并对各改进型模型进行相对误差、方差比和小误差概率检验,将检验后的最优模型用于预测晚霜冻。结果表明,3种改进方法同时结合后所建模型的预测效果最理想,用来预测晚霜冻具有较高的可信度,根据模型预测,阳城县在2001年最后一次出现晚霜冻后,未来出现晚霜冻的年份为2030年和2044年。研究结果旨在为当地农业生产防御晚霜冻提供可参考的理论依据。
The latest beginning date of late frost in springs in 1957 -2013 about Yangcheng county of Shanxi province was as zero point, and then the relative dates that they were zero point minus those appearance dates could be obtained. More recent,the abrupt date from zero point was the catastrophic threshold. Further, the interannual variation of the relative date and its intersection point with the threshold line were drawn. Then, the distance about the second intersection point and the first point was worked out. And every other distance behind the second intersection point and the first point were obtained. Finally, the original date sequence of Model GM （ 1, 1 ） was obtained, and the traditional model GM （ 1, 1 ） was set up. This model could be improved through those methods, which had majorized sequence, the background value, pessimistic sequence of equidimensional filling vacancies method and so on. And different improved models had been tested by means of the relative error, variance ratio and small error probability. The optimal model tested could be applied to forecasting late frost. The results showed that, this model established through the three improvement way had the best prediction effect, and had higher credibility to predict the last frost. According to the model prediction, late frost would be appeared in 2030 and 2044 in Yangcheng after 2001. The results can be a referentially theoretical basis for defending late frost.
出处
《中国农业气象》
CSCD
北大核心
2014年第3期305-310,共6页
Chinese Journal of Agrometeorology
