靖远县近60年来农业气候资源变化特征

Change Characteristics of Agroclimatic Resources in Jingyuan County for Nearly 60 Years

为了全面分析气候变暖背景下靖远县农业气候资源变化特征,为该区合理利用气候资源及农业生产提供科学参考,利用靖远县近60年来气温、降水、日照观测资料,采用线性趋势分析、Mann-Kendal突变检验、功率谱等数理统计方法,分析了该区农业气候资源的变化特征。结果表明:(1)在全球气候变暖的大背景下,靖远县热量资源明显增加,年平均气温变化倾向率为0.17℃/10 a,存在9年和4年的显著周期,在1994年出现了增温的突变。日平均气温稳定通过0℃、10℃活动积温,平均每10年分别增加25.5℃·d和34.3℃·d。(2)靖远县年降水量呈弱的减少趋势,变化倾向率为-5.3 mm/10 a,降水主要集中在夏季,年际变化大,旱涝灾害易发。降水变化存在7.6年和3年的显著周期。(3)靖远县年总日照时数为2706.4 h,夏作物生长期(4—7月)总日照时数为1010 h左右,秋作物生长期(5—9月)总日照时数为1233.6 h左右。年总日照时数从20世纪70年代开始发生"减少—增多"的转型。年总日照时数变化存在4.5年左右的显著变化周期。

In order to overall analyze the change characteristics of agroclimatic resources in Jingyuan County under the background of climatic warming, providing scientific reference for reasonably utilizing climatic resources and agricultural production. The author used the observation data, including temperature, rainfall and sunlight hours over the recent 60 years and the statistical methods of linear-trend analysis, Mann-Kendall and power spectrum, the long-term changes in agroclimatic resources in Jingyuan County were analyzed. The results showed that：（1） in the context of global warming, the heat resources of Jingyuan County significantly increased tendency of the annual average temperature change rate of 0.17°C/10 a, there were 9 a and 4 a significant periods and mutations of warming in 1994. The active accumulated temperature for daily mean temperature steadily through 0℃ and 10℃ showed increasing trends, with rates of 25.5 ℃.d/10 a and 34.3 ℃.d/ 10 a, respectively.（2） The annual precipitation of Jingyuan County showed a trend of weak reduction and change tendency rate was-5.3 mm/10 a, the precipitation mainly concentrated in the summer, with a large inter-annual change, and prone to droughts and flood disasters. Changes in precipitation showed 7.6 a and 3 a significant periods.（3） The annual amount sunshine duration was 2706.4 h in Jingyuan County, with regard tosummer crop growing season（April to July） and autumn crop growing season（May to September）, the total sunshine duration are about 1010 h and 1233.6 h, respectively. The annual amount sunshine duration transformed reduction into increase from the 1970s and showed 4.5 a significant changes periods.