石羊河流域≥10℃积温时空变化特征

Spatial and temporal change characteristics of≥10℃accumulative temperature in Shiyang River Basin

利用1960-2017年石羊河流域5个气象站逐日平均气温资料,采用滑动平均方法,确定了≥10℃积温的界限;通过运用多元线性回归、均方差(σ)、线性趋势系数、累计距平和信噪比等方法,分析了石羊河流域≥10℃积温的时空变化特征。结果表明:石羊河流域≥10℃积温具有明显地域特征,≥10℃积温的均值和极值均为荒漠区高于绿洲平原区,绿洲平原区高于山区,≥10℃积温的空间分布与所受天气系统以及经、纬度和海拔高度的关系非常密切。≥10℃积温正常年份最多,概率超过65%,依次向两端迅速递减。年、年代≥10℃积温呈显著升高趋势。≥10℃积温主要在5~9月,7月为高峰值。≥10℃积温气候突变全流域、民勤和天祝在1996年,永昌、凉州和古浪在1997年。石羊河流域≥10℃积温升高使喜凉作物种植面积缩小,生育期缩短,不利于高产的形成;而使喜温作物种植面积扩大,生育期延长,有利于高产和高品质的形成。本研究将对现代农业结构规划、农作物品种调整以及农业的定量化评估具有重要意义。

Accumulative temperature is an important climate resource and crop growth and development index.In this paper,using daily average temperatures of five meteorological stations in Shiyang River Basin,Gansu Province,China during 1960-2017,acumulative≥10℃temperature was determined using the sliding average method.Spatiotemporal changes in acumulative≥10℃temperature were analyzed via multiple linear regression,mean square deviation(σ),linear trend coefficient,cumulative anomaly,and signal-to-noise ratio methods.The results showed that the acumulative≥10℃temperature of Shiyang River Basin has obvious regional characteristics.In the desert area,the average and extreme values of acumulative≥10℃temperature were higher than those in the oasis plain,and the temperature in the oasis plain was higher than that in the mountainous area.The regional distribution of acumulative≥10℃temperature was closely related to the weather system,longitude,latitude,and altitude.In normal years,acumulative≥10℃temperature was the most common,the probability of which exceeded 65%,which was the ends of decline.Annual and decadal acumulative≥10℃temperatures showed a significant upward trend.The acumulative≥10℃temperature mainly occurs from May to September,with the highest peak in July.Abrupt changes in acumulative≥10℃temperature occurred in the entire basin,including Minqin and Tianzhu in 1996,and Liangzhou,Yongchang,and Gulang in 1997.When the acumulative≥10℃temperature in the Shiyang River Basin rises,the planting zones decrease and the growth period becomes shorter,which is not favorable for the high yields of cool-weather crops and while it is favorable for the warm-weather crops.This paper revealed new pattern of heat resources and its impacts on agriculture in Shiyang River Basin.This is very important for modern agricultural planning,crop variety adjustment,and agricultural quantitative evaluation.