设施蔬菜越冬期极端低温的分布及重现期特征——以关中、陕北地区为例

【关键词】:设施蔬菜;;严重冻害;;极端低温;;重现期;;陕北;;关中
【摘要】:利用陕西陕北、关中地区1970~2010年66个县/区设施蔬菜越冬期资料建立了各站逐年极端最低气温、低于逐日最低气温5%阈值的气温和逐年出现严重冻害次数等3组资料的时间序列,分别对越冬期极端低温出现几率、强度进行了特征分析,利用耿贝尔分布方法建立了7个代表站年极端最低气温的分布模型及重现期预测。结果表明:1)对于严重冻害出现频次,延安东部的黄河沿岸地区在0.6~3.7次/年,陕北其它地区在4.3~18.7次/年,长武、旬邑和麟游渭北北部塬区在6.5~11.1次/年,关中其它地区在0.0~3.7次/年;2)低于逐日最低气温5%阈值的气温多年平均陕北地区、关中地区分别为-15.1~-19.9℃、-6.1~-8.7℃,严重冻害关中地区出现几率不足5%,陕北部分地区出现几率超过5%;3)陕北地区在不足2a的重现期,关中地区在8a的重现期会出现严重冻害,相同重现期关中地区冻害强度远低于陕北地区。
The time series of each station's annual lowest temperature,extremely temperature that lower than the daily lowest temperature by 5% threshold value and the numbers of yearly serious frozen injury events had established by using the daily lowest temperature data of overwintering period during 1970~2010 from 66 Meteorological stations in arid and semi-arid regions of Shaanxi province.Subsequently the feature analysis of the probability and intensity about the extreme cold disaster of facility vegetables in overwintering period had presented.Gumbel distribution was applied as the analysis method,then probability distribution model was established and recurrence intervals of extreme cold disaster of 7 representative stations were predicted.It had showed that: 1)To the frequency of extreme cold disaster accourred 0.6~3.7 times per year in the Yan'an eastern along the Yellow River,4.3~18.7 times per year in the other regions of North Shaanxi area,6.5~11.1 times per year in Changwu,Xunyi and Linyou of Weibei northern highland,0.0~3.7 times per year in other region of Guanzhong area.2)The multi-annual mean temperature for those the temperature is lower than the daily lowest temperature 5% threshold value were represented,which in North Shaanxi area and the Guanzhong area were respectively-15.1~-19.9℃,-6.1~-8.7℃.The severe cold disaster area in Guanzhong presented the probability of insufficient 5%,some areas of the North Shaanxi presented the probability of surpass 5%.3)The North Shaanxi area was in the insufficient 2a recurrence periods of the severe cold disaster,while the Guanzhong area was in the 8a recurrence periods.In the same recurrence period,the severe cold disaster intensity of Guanzhong area could be far more lower than the North Shaanxi area.