Quantitative Analysis of the Impact of Climate Change on Winter Wheat Yield in Henan Province

T The daily observation data of meteorological stations in Henan Province from 1979 to 2018 are utilized, together with the teleconnection factors such as PDO (Pacific Decadal Oscillation) and ENSO (EI Nino Southern Oscillation), to analyze the impact of precipitation, temperature, sunshine hours, relative humidity, PDO and ENSO on the winter wheat yield in Henan Province during its growth period.The research results exhibit the upward trend of the precipitation, the average temperature, the maximum temperature and the minimum temperature as well as the downward trend of sunshine hours and relative humidity.Moreover, the average temperature and the minimum temperature have increased significantly, while the relative humidity has decreased dramatically.The climate output separated by the H-P filtering method increases with the increase of the period, and the amplitude of the volatility within the period decreases; the residual trend method is used to analyze the relative contribution rates of climate change and human activities to winter wheat yield, which are 30.15% and 69.85% respectively.The fluctuation of winter wheat yield in Henan Province is lessening, and climate change is not the leading factor causing yield variation of winter wheat.