关键词: 冬小麦, 豫北地区, 气候变化, 播种面积, 产量, GEE

Abstract: In order to study the impact of climate change on the sown area and yield of winter wheat in Northern Henan，the Landsat image data from 1985 to 2019 were constructed by using Google Earth Engine （GEE）cloud platform.The distribution information of winter wheat was extracted by random forest（RF）algorithm，and the changes in the sowing area of winter wheat in northern Henan were analyzed.Combined with the meteorological observation data of 9 known meteorological stations in northern Henan，spatiotemporal trends of the average temperature，precipitation，sunshine hours at the sowing date，jointing⁃heading stage，and heading⁃milk ripening stage were analyzed.The data of sowing area and yield in the study area were quantitatively analyzed.The correlation analysis，importance evaluation and sensitivity analysis of winter wheat yield to climate were carried out.The results showed that，the relative errors of the classification and extraction results of RF algorithm were all within 3.5%，the average accuracy of sample points was 94.94%，and the Kappa coefficient was between 0.88 and 0.94，reaching a high precision level.The total sowing area of winter wheat showed an increasing trend from 1985 to 2019，mainly distributed in the central and eastern regions，and the sowing frequency was higher in the central region.The temperature increasing at sowing date had a positive effect on the sowing area（P=0.013<0.05）.The importance of climate factors on the sowing area was ranked as follows：average temperature > sunshine hours > precipitation at sowing date. Winter wheat yield showed a trend of increasing in northern Henan.Precipitation at jointing⁃heading stage significantly promoted winter wheat yield（P=0.003<0.01）with a relatively higher contribution rate，while sunshine hours significantly inhibited winter wheat yield（P=0.022<0.05）.The yield of winter wheat was most sensitive to sunshine hours during heading⁃milk ripening stage. The order of importance of climate factors on winter wheat yield in northern Henan was as follows：precipitation at jointing⁃heading stage>average temperature at jointing⁃heading stage>precipitation at heading⁃milk ripening stage>sunshine hours at jointing⁃heading stage>sunshine hours at heading⁃milk ripening stage>average temperature at heading⁃milk ripening stage

Key words: Winter wheat, Northern Henan, Climate change, Sowing area, Yield, GEE