乌兰地区日照时数变化特征及其对牧草的影响

THE VARIATION CHARACTERISTICS OF SUNSHINEHOURS IN THE WULAN REGION AND THEIR IMPACT ON FORAGE

根据乌兰地区2个地面气象观测站1988~2022年的逐月日照时数资料和2013~2017年牧草资料,运用线性回归、滑动平均、相关分析和小波分析法分析了乌兰地区日照时数变化特征和日照对牧草的影响。结果表明:乌兰地区近35a各月日照时数最大值出现在5月,为274.6h,月最小日照时数出现在2月。各季节的日照时数春季呈上升趋势,其他季节总体呈下降趋势;秋季日照时数以17.2h/10a的速率显著减少,冬季日照时数下降趋势最小。年日照时数以44.2h/10a的速率呈下降趋势。乌兰地区日照时数存在8~10a和1~2a的周期振荡。乌兰地区牧草生长季(4~8月)日照时数为1328h,为全年日照时数的45%,2013~2017年总产草量呈缓慢上升趋势,日照时数与产草量呈负相关。

Based on the monthly sunshine hours data from two ground meteorological observation stations in the Wulan region from 1988 to 2022 and Grassland data from 2013 to 2017 in Wulan,Linear regression,moving average,correlation analysis,and wavelet analysis were used to analyze the characteristics of sunshine duration changes and the impact of sunshine on forage in the Wulan region.The results showed that the maximum monthly sunshine hours in the Wulan region in the past 35 years occurred in May,with 274.6 hours of sunshine.The minimum monthly sunshine hours appeared in February.The sunshine hours in different seasons in the Wulan region showed an upward trend in spring,while in other seasons,they generally showed a downward trend.The trend of autumn sunshine hours in the Wulan region was significantly decreased at 17.2h/10a,while the trend of winter sunshine hours was the smallest decline.The annual sunshine hours showed a decreasing trend at a rate of 44.2 h/10 a.There are periodic oscillations of 8~10 years and 1~2 years of sunshine hours in the Wulan region.In the grass growing season(April-August)in Wulan region,the sunshine duration were about 1328 hours,which was 45%of the total sunshine duration of the whole year.The total grass yields were increased slowly from 2013 to 2017.There was a negative correlation between sunshine duration and grass yield in Wulan.