石家庄地区冬小麦适播期时空变化分析

Spatial and temporal variations in optimum sowing date of winter wheat in Shijiazhuang City

气候变暖改变了作物的生长环境,冬季积温的增加使冬小麦的最佳播种期发生了改变,因此,为了更好地指导农业生产,分析气候变暖背景下冬小麦最佳播期的变化就显得尤为必要。基于这个目的,本文利用石家庄地区9个气象站1963—2012年的逐日气象数据,采用趋势分析、Mann-Kendall突变检验和Morlet小波等分析方法,对该地区冬小麦适播期（冬前积温为495~570℃·d）的时空变化进行了分析。结果表明：近50 a来,石家庄地区山区冬小麦的适播期后延了3~4 d,山前平原区后延了5~7 d；在近50 a的时间序列里,山前平原区冬小麦的适播期发生了突变过程,突变发生年出现在1995年左右,在2006年左右适播期后延趋势显著增强；该地区冬小麦适播期自北向南相差3~4 d。山区部分的冬小麦适播期随气候变暖的变化不明显,近50 a的变化趋势为-0.1~0.4 d·10a^-1；山前平原变化趋势较大,增加趋势为0.4~1.3 d·10a^-1。该研究对当地冬小麦可起到积极的指导作用。

Global warming can change the ecological environment. The optimum sowing date of winter wheat has changed with increasing accumulated temperature before winter. Thus there was the necessity to analyze the changes in optimum sowing date of winter wheat under warming climate conditions. To this end, the spatial and temporal variations in optimum sowing date of winter wheat were analyzed using daily meteorological data （accumulative temperature before winter was in range of, 495-570 ℃·d） for 1963–2012 from 9 meteorological observatory stations in Shijiazhuang. Statistical methods including Trend Analysis, Mann-Kendall Mutation Test, Morlet Wavelet Analysis were used in the study. The results showed that the change in optimum sowing date of winter wheat in the mountain area of Shijiazhuang was not obvious, with a change trend of 0.149–0.296 d·10a-1. Then the change in optimum sowing date of winter wheat in the piedmont plain was statistically significant, with a change trend of 0.822–1.211 d·10a-1. The optimum date of sowing of winter wheat delayed 5–7 days in the investigated 50-year period. The Mann-Kendall Mutation Test result showed a temporal process of change in optimum sowing date of winter wheat around 1995, with an obvious delaying trend after 2006. The results of the Morlet Wavelet Test showed the existence of about 5-year periodic change in optimum sowing date of winter wheat during the investigated 50-year period. The cycles of change in optimum sowing date of winter wheat were the same for both the mountain and plain regions. From the cycles, it was deduced that the trend in optimum sowing date of winter wheat relatively accelerated after 2010. There was 3–4 days difference of optimum sowing date of winter wheat from the north to south of Shijiazhuang. The change in optimum sowing date of winter wheat in the mountain area of Shijiazhuang due to climate warming was moderate, which was-0.1–0.4 d·10a^-1 in the investigated 50-year period. However, the change in optimum sowing date of winter wheat in the piedmont plain area was obvious, with a trend of 0.4–1.3 d·10a^-1. The trend of change in optimum sowing date of winter wheat in the plain area was far faster than that in the mountain area. The research result was critical for optimizing local winter wheat production in the Shijiazhuang study area.