Impacts Of Agrometeorological Disasters And Temperature And Precipitation On Grain Yield In North China Plain

Food security is a topic that China needs to pay close attention to for a long time.North China Plain is China's main wheat and maize producing area.Analysis on the impacts of agricultural meteorological disasters,temperature and precipitation on grain yield will provide scientific basis for formulating the adaptation strategies for agricultural adaptation to climate changes.Affected area data from 1986 to 2012 was used to analyze the characteristics of major agricultural meteorological disasters and their effects on grain yield.Based on meteorological data of Henan,Hebei and Shandong provinces of North China Plain from 1978 to 2012,the changes in temperature,agricultural boundary temperature and precipitation of three provinces were analyzed by calculating the climatic tendency rate.Based on temperature and precipitation data and agricultural input data,the Cobb-Douglas function in economics,by introducing the climate revision module,was used to build an economic-climate model.The economic-climate model(C-D-C model)could analyze the contribution of labor,land and technology progress,the technological progress factors can assess the effectiveness of climate change adaptation strategies to grain production.The main conclusions are as followed:(1)Agro-meteorological disasters in Hebei,Henan and Shandong showed a decreasing trend from 1986 to 2012.The grain loss rates caused by agrometeorological disasters in Hebei,Henan,and Shandong were 7.9 to 17.2%,6.0 to 13.3%,and 6.6 to 14.8%,respectively.The disaster loss rate in Hebei Province was in order of drought,hail,flood and low temperature.But the disaster loss rate in Henan Province and Shandong Province was in order of drought,flood,hail and low temperature.Flood and low-temperature occurred occasionally.Flood in Henan was the most fluctuant and low-temperature in Shandong was the most fluctuant.Drought and wind hail were the constant disasters,and drought and hail in Hebei were the least fluctuant.The results showed that drought and hail were constant disasters,and the annual fluctuation was small,which has a great impact on agricultural production.But the effects of flood and low temperature were relatively small,with great annual variability and strong intensity.(2)Average temperature in the three provinces of North China Plain increased significantly throughout the year,winter wheat growth period and summer maize growth period from 1978 to 2012.And the largest increase occurred in 1990 s.The first date of average daily temperature greater than 5? in Hebei Province and Shandong Province and that greater than 0? and 15? in Henan Province were advanced.The last date of average daily temperature greater than 0?,5?,10? and 15? in Hebei Province,Henan Province and Shandong Province showed an insignificant rising trend.The duration of average daily temperature greater than 5? in Hebei Province,that greater than 0? and 15? in Henan Province and that greater than 5?,10? and 15? in Shandong Province increased.The variation of thermal resources and precipitation in the growing season of winter wheat was not significant,and the effect of average temperature and precipitation on the yield was not significant.There was no significant change in the annual precipitation in Hebei Province and Henan Province,and the annual precipitation in Shandong Province increased significantly.There was no significant change in the precipitation during the growth period of winter wheat and summer maize in the three provinces.(3)The winter wheat planting area in Henan Province increased significantly from 1978 to 2012,but Shandong Province significantly decreased.The winter wheat yield and unit area yield increased significantly in three provinces of North China Plain.The sown area,total yield,and yield per unit area of maize also increased significantly in three provinces of North China Plain.The average temperature and precipitation of winter wheat had no significant effect on the yield.Winter wheat sown area,labor input and technological progress all had a positive impact on production.The greatest impact was sown area,followed by technological progress.The precipitation of maize in Hebei Province and Shandong Province had a negative effect on the yield considering irrigation.Maize sown area and technological progress all had a positive impact on production under the premise of considering irrigation.The greatest impact was sown area,followed by technological progress.It showed that in the situation where arable land resources tended to be saturated and the number of rural laborers were decreasing,the future increase in grain yield would mainly depend on technological progress.