近60年陇东地区极端气温变化特征及对农业生产的影响

Variation Characteristics of Extreme Temperature and Its Impact on Agricultural Production in Eastern Gansu in Recent 60 Years

基于陇东地区1961—2020年有代表性的区域环县、庆城、西峰的气象站逐日最高气温、最低气温资料,通过选取12个具有代表性的极端气温指数,应用线性倾向法、距平法研究了陇东地区极端气温指数的变化特征。结果表明:研究区域日最高(最低)气温极值、暖昼日数、夏季日数及热夜日数等指数呈上升趋势,冰冻日数、霜冻日数等指数呈下降趋势,极端暖指标为增加趋势,极端冷指标为减少趋势,日极端最高气温小于日极端最低气温的增温幅度。陇东不同地域极端气温指数变化既有相似性又各具特色,环县的夏季日数增加显著,西峰的霜冻日数减少最为明显,庆城介于两者之间。总体来看,陇东地区热量资源增加,无霜期延长,有利于作物种植结构的调整及特色作物的引种,但极端气温的变化引发的冻害及高温干旱天气使农业生产和粮食安全的不稳定性增加,使农业生产的风险加剧。因此,在农业生产中要顺应气候的变化趋势,充分利用气候资源,大力发展精准农业、高效农业,有效规避或缓解极端气温事件对农业生产带来的不利影响。

Based on the daily maximum and minimum temperature data of meteorological stations in Huanxian,Qingcheng and Xifeng in the representative regions of Eastern Gansu from 1961 to 2020,12 representative extreme temperature indexes were selected,and the variation characteristics of extreme temperature indexes in Eastern Gansu were studied by linear tendency method and anomaly method.The results show that the maximum(minimum)temperature extremes,warm days,summer days and hot night days in the study area show an upward trend,while the freezing days and frost days show a downward trend.The extreme warm index shows an increasing trend.The extreme cold index shows a decreasing trend,and the extreme maximum temperature is less than the temperature increase range of the extreme minimum temperature.The change of extreme temperature index in different regions of Eastern Gansu has both similarities and characteristics.The number of summer days in Huanxian increases significantly.The number of frost days in Xifeng decreases most significantly,and Qingcheng is between the two.In general,the increase of heat resources and the extension of frost free period in East Gansu are conducive to the adjustment of crop planting structure and the introduction of characteristic crops.However,the freezing injury and high temperature and dry weather caused by extreme temperature changes increase the instability of agricultural production and food security,and aggravate the risk of agricultural production.Therefore,in agricultural production,we should comply with the trend of climate change,make full use of climate resources,vigorously develop precision agriculture and efficient agriculture,and effectively avoid or reduce the adverse impact of extreme temperature events on agricultural production.