| In this paper based on the daily mean temperature,daily average precipitation in the 74 meteorological stations in the three provinces of Northeast China from 1978 to 2012,by screening and missing measurement interpolation using many analytic methods,such as 5-day sliding average method,climate tendency rate regression analysis method,the temporal and spatial variation characteristics of annual average temperature,annual average precipitation,and the beginning and ending dates of threshold temperature and the number of continuous days through ?0°C,?5°C,?10°C and ?15°C in three provinces of Northeast China were analyzed.Then based on crop disaster data of flood,drought,wind and hail and low temperature in the three northeastern provinces from 1986 to 2012,by calculating the yield loss rate of a disaster and classifying the disaster,analyzes the general situation of agrometeorological disasters in Northeast China,the trend of each disaster,the occurrence state of main meteorological disasters and the risk probability of serious disasters,and the characteristics of meteorological disasters in Northeast China in recent years are obtained.Finally,based on the total output value of agriculture,forestry,animal husbandry and fishery,the total agricultural output value,the effective irrigation area,the application of agricultural fertilizer,the total power of agricultural machinery,the total sowing area of crops,the sowing area of rice,the sowing area of maize,the three provinces in Northeast China from 1978 to 2012,Total grain yield,total yield of rice,total yield of maize,yield of rice per unit area,yield of maize per unit area,the establishment of economic-climate models and the technological advances resolved,the characteristics of climate change in Northeast China and its influence on grain crop yield are analyzed.It provides a data reference for the next step to put forward the countermeasures to adapt to climate change in Northeast China.The main results are as follows:(1)It is also a disaster-prone region in Northeast China.On the whole,the drought increased year by year,while the chilling injury,wind and hail increased first and then decreased in Northeast China.Combined integrated average loss rate of Liaoning,Jilin,Heilongjiang Province,was 9.9%-20.9%,10.7%-22.5% and 8.3%-17.8%,respectively.Liaoning drought disaster is the most serious disasters,drought loss rate of 68.3%,the average annual occurrence of major disasters once every 15 years,the lightest is Heilongjiang,and the drought loss rate is 54.4%,but the number of major disasters occur more,once every decade.Flood disaster in Heilongjiang is the most serious disasters,flood loss rate is 31%,the lightest is Liaoning,and the flood loss rate is 22%,the average annual occurrence of major disasters once every 15 years.Wind and hail disaster in Jilin is the most serious disasters,accounting for 9%,Liaoning is the lightest.The most serious area of chilling injury is Heilongjiang,accounting for 6.5%,Jilin 4.5%,Liaoning 3.1%.Major wind and hail and chilling injury in northeast China occur once every ten to fifteen years.The coefficient of variation of the disaster shows that wind and hail and drought are normal disaster,which has a great impact on agricultural production.But the effects of chilling injury and flood are relatively small,with great annual variability and strong intensity.(2)From 1978 to 2012,the starting dates of threshold temperatures of ?0°C,?5°C,?10°C and ?15°C in the three provinces of Northeast China showed an advance trend.Liaoning Province advances 1.5,1,0.1,2.2 days per 10 years.Jilin Province advances 0.5,1,1.7,1.5 days per 10 years.Heilongjiang Province advances 1,1.6,2.1,1.1 days per 10 years.But the end date tends to be postponed.Liaoning Province is postponed 0.6,1.8,1.3,1.7 days every 10 years.Jilin Province is postponed 2.5,1.3,1.9,1.7 days every 10 years.Heilongjiang Province is postponed 2.5,1.7,1.7,1.3 days every 10 years.The threshold temperature start date advance rate is less than the end date delay rate.The number of continuous days at the boundary temperature is increasing Liaoning Province increased by 2.1,1.8,2.4,3.9 days every 10 years.Jilin Province increased by 3.1,2.4,3.6,3.2 days every 10 years.Heilongjiang Province increased by 3.5,3.3,3.7,2.4 days every 10 years.Provide abundant heat resources for agricultural production in Northeast China.With the decrease of latitude,the starting date of the boundary temperature change is earlier,the end date is delayed,and the number of continuous days is increased.The beginning of the limit temperature is most early in the southern parts of the provinces,the earliest termination dates were in the northern and north-eastern provinces.There is a great difference between the north and south of the threshold temperature starting date,the difference between the north and the south on the end date is small,and the difference between the north and the south of the limit temperature lasting.(3)In recent years,crop sown area has the greatest effect on crop yield,followed by technological progress,and labor input has little effect on maize and rice yield in Northeast China,and both of them have positive effects.Temperature had no significant effect on maize yield and rice yield in Northeast China,but precipitation had no significant effect on other crop yields except for rice yield in Liaoning Province.The results show that the effects of temperature and precipitation on maize and rice yield in Liaoning Province belong to the normal type.The variation of temperature and precipitation had no effect on the yield of maize and rice in Northeast China from 1978 to 2012.As a result of technological progress,the effect of chemical fertilizer input on crop yield was significant,while agricultural machinery input had no significant effect on the yield of maize and rice in Heilongjiang province,while the others were significant.The effect of effective irrigation area was not significant,and the input of agricultural machinery was negative. |
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