张家口地区43年寡照日数特征分析

Analysis on Climatic Characteristics in the Spare Sunlight Conditions in Zhangjiakou Region in Recent 43 Years

采用1972—2015年43年的逐日日照资料,分析张家口地区寡照(逐日日照时数≤3 h)日数特征分析,结果表明:43年日照时数呈减少趋势,光照条件坝上大于坝下;寡照日数总体呈上升趋势,2000年后趋势明显;6年滑动平均分布曲线分为低值期和和上升期;43年寡照日数仅占全年日照的14.8%,各季略有差异:秋冬2季占全年寡照日数的57%,具有冬多春少的分布特点,寡照日数8—12月较多,特别是11—12月,日照时数过短对设施作物生长有不良影响;轻度和中度寡照次数变化曲线与6年滑动平均分析结果相比提前5年,重度寡照次数出现次数极少,主要在坝下南部4县,各等级寡照次数均呈显著的上升趋势,轻度寡照事件(较显著)发生次数明显多于中度事件(显著)次数。寡照天气设施蔬果生长缓慢,灰霉病发病率增多,菜农要尽量延长蔬果见光时间,通过清洁棚膜增加透光度,进行棚内小气候调控,加强蔬果病害监测防治,确保蔬果安全生产。

In this paper,the character of spare sunlight （daily sunlight hours ≤ 3 hours） days was analyzed based on daily data in Zhangjiakou regian from 1972 to 2015.The results showed that in the past 43 years, annual sunlight number decreased, the sunlight condition in Bashang region was better than that in Baxia region.The number of spare sunlight days generally showed an upward trend, and the trend was even more obvious since 2000 ; 6-year moving average curve was divided into low value period and rising period.In recent 43 years, spare sunlight clays accounted for only 14.8% of the total sunlight days, and there was a little difference in each season.The spare sunlight days in autumn and winter accounted for 57% of the annual days.The distribution of spare sunlight was more in winter and less in spring.There were more spare sunlight clays between August and December, especially in November and December.Short duration of sunlight had adverse effects on the growth of the facility crops.The curves of spare sunlight in mild and moderate grade varied 5 years earlier than the 6-year moving average curve.The severe spare sunlight condition was very rare, mainly appeared in four county towns which were in the south of Baxia region.The upward trend for the number of spare sunlight in different grade was obvious ,and the mild spare sunlight condition was more than the moderate ones.The facility crops growed more slowly and had higher Gray Mold disease incidence in the spare sunlight condition.Therefore, to ensure the safety of production, farmers should prolong the sunlight time of crops, improve the light transmittance through cleaning greenhouse film, adjust the greenhouse microelimate, strengthen the monitoring of crops diseases.