Estimation for Weather Yield of Winter Wheat Under A2 and B2 Scenarios in Hebei, Shandong and Henan Provinces

Winter wheat is one of the main crops in China. Hebei, Shandong and Henan provinces are the main planting areas for winter wheat in China. It is important for China to recognize the change of weather yield for winter wheat in the next several decades.Trend yield models of winter wheat are built based on statistical yield from 1978 to 2008 using nonlinear simulation method for Hebei, Shandong and Henan provinces. Multiple correlation coefficients of trend yield models are greater than 0.90 for each province. Then, weather yields of winter wheat are got by subtracting the trend yield from statistical yields for each province. Historical meteorological data from 1978 to 2008 are disposed to get the average data (or maximum or minimum or sum) of every ten days for three provinces. Disposed meteorological data and weather yields of winter wheat are used to establish the models, whose significance reaches 0.05 level.In order to predict the weather yields of winter wheat, meteorological data coming from regional climate model (PRECIS) are used. The average data (or maximum or minimum or sum) of every ten days for each province for the reference period of 1978—1990 are achieved, as well as the data for future climate change under A2 and B2 scenarios of 2011—2050. Weather yields of winter wheat for the reference period are computed by using disposed meteorological data with weather yield models for Hebei, Shandong and Henan provinces. Meanwhile, trend yields of winter wheat are calculated using trend yield models by province. The total yields of each province from 1979 to 1990 are summed by weather yields and trend yields, which are compared with statistical yields. The results show that the correlation coefficients are 0.928, 0.792 and 0.837 for Hebei, Shandong and Henan. The significance reaches 0.001 level for Hebei and Henan, 0.002 level for Shandong.Weather yields of winter wheat are simulated based on weather yield models under A2 and B2 scenarios from 2012 to 2050 with disposed regional climate model (PRECIS) data for Hebei, Shandong and Henan provinces. The results show that in both A2 and B2 scenarios, the weather yields of winter wheat deduce for Hebei and Henan, with increase for Shandong for most years of 2012—2050.