基于气候变暖背景的西安市冬小麦适播期分析

Analysis on Suitable Sowing Date of Winter Wheat Based on the Background of Climate Warming in Xi’an

【目的】探明西安市冬小麦适播期及预报方法,为当地冬小麦适播温度指标和适播期的确定提供科学依据。【方法】根据西安市7个国家气象站1961-2018年当年9月至翌年2月逐日平均气温资料,采用线性趋势、5日滑动平均、M-K检验、积温学指标法分析冬小麦适播期。【结果】西安市冬小麦适宜播种温度为14~17℃,随时间推移播种期平均气温呈上升趋势,每10年播种期推迟1.0~1.5 d,日平均温度稳定通过14~17℃(14℃、15℃、16℃、17℃)各界限温度、0℃的平均日期变化趋势均由东南向西北递增,东南部明显偏早,东南部与西北部的平均适播期相差3~5 d,停止生长期相差11 d;冬前平均气温、积温均呈上升趋势,在1997年左右发生突变;1977年以来西安市冬季一直偏暖。【结论】在气候变暖背景下,西安市冬小麦适播期为10月9-14日,最晚播期为10月20日。

【Objective】To provide the scientific basis for determination of suitable sowing temperature index and suitable sowing date of winter wheat by discussing suitable sowing date and forecasting method of winter wheat in Xi’an.【Method】The methods of linear trend,5-day moving average,M-K test and accumulated temperature index are used to analyse suitable sowing date of winter wheat based on daily mean temperature data from September to February of the following year during 1961-2018 from 7 national meteorological stations in Xi’an.【Result】The suitable sowing temperature of winter wheat is 14~17℃.The sowing date is postponed for 1.0~1.5 d every 10 years because the average temperature of the sowing date is on the rise with time lapse.The daily mean temperature steadily gets through the limit of different temperature from 14 to 17(14℃、15℃、16℃,17℃)and The mean date change trend of 0℃increases from southeast to northwest.The mean suitable sowing date in southeast is 3~5 d earlier than in northwest and the difference in the stopping growth date between southeast and northwest is 11 days.The mean temperature and accumulated temperature before winter both are on the rise but the abrupt change occurred in 1997.The winter season in Xi’an has been warmer since 1977.【Conclusion】The suitable sowing date and latest sowing date of winter wheat is on October 9-14 and October 20 under the background of climate warming in Xi’an respectively.