Effects Of Drought On Grain Yield Of Main Grain Producing Areas In China And Countermeasures For Drought Resistance

Drought is one of the major disasters in China.The grain production of 13 major grain producing provinces accounts for more than 75% of that the whole country,It is of great significance to improve the drought resistance and disaster reduction capacity of major grain producing provinces by analyzing the change trend of grain production the impact of drought on grain production in 13 major grain producing provinces since the founding of the people's Republic of China.In this study,we collected the data of crop sown area,drought disaster area and grain yield of 13 major grain producing provinces in China since the founding of the people's Republic of China,systematically analyzed the change trend of grain production and the impact of drought on Grain Yield in 13 major grain producing provinces in China,and summarizes the drought relief measures in different regions with some provinces as examples.Finally,based on the global climate model,simulated and predicted the frequency of different drought levels and the proportions of different drought levels in China from 2031 to 2060 in China's country-wide and main grain producing province under RCP4.5 and RCP8.5 scenarios,predict the evolution trend of drought in China's main grain producing areas under future scenarios.The main conclusions of the paper are as follows:(1)Since the founding of the People's Republic of China,the drought-affected and drought-suffered areas in Northeast China have gradually increased.The drought-affected rate and drought-suffered rate are higher than those of the other three regions.Among them,Inner Mongolia Province has the highest average drought-affected and drought-suffered rate,followed by Liaolin.The grain planting area of Heilongjiang,Jilin and Inner Mongolia in the northeastern region has gradually increased.The planting area with grain in the Huanghuaihai area has remained basically stable.In the middle and lower reaches of the Yangtze River and the southwestern region,droughts have significantly reduced grain yields and total yields,and drought-affected and drought-suffered rates were negatively correlated with grain yields and total yields.The drought-affected and drought-suffered rates of most major food-producing provinces are negatively correlated with the annual rate of change of grain yield and total production to a significant or extremely significant level,the year with higher drought-affected and drought-suffered rates corresponds to the year with larger reduction of grain yield per unit area and total yield.(2)Different planting areas have different drought disaster resistance and reduction measures.In the Northeast,there are mainly drought-resistant measures such as seedling transplanting,ridge cultivation,film mulching and no-tillage for maize,and drought-resistant technologies such as adjustment of farming methods and emergency supplementary irrigation for soybeans.For winter wheat and summer maize in North China,there are mainly straw mulching,emergency supplementary irrigation technology and optimized irrigation measures for drought resistance and disaster reduction technologies.In Southwest Sichuan Province,drought mitigation measures mainly include four aspects: reasonable planting system and crop layout,reasonable farming technology,adjusting appropriate sowing date and management technology to avoid the impact of drought,and agricultural measures for disaster mitigation.Hunan Province is located in the south of China,with a large annual rainfall,but prone to seasonal drought.In Hunan Province,we mainly adopt the planting mode of avoiding drought and reducing disaster,using chemical agents to control the technology of avoiding drought and reducing disaster,and the high-yield cultivation technology of drought adaptive prevention and control.(3)Under the condition of continuous climate warming,the occurrence of drought in China will be further intensified.In this paper,based on the global climate change model,the drought degree of main grain producing area in 2031-2060 will be simulated and predicted,The results show that the frequency of drought in most areas of China is more than 15% under the scenario of RCP 4.5.The frequency of drought in Northeast,Huanghuaihai,Southwest,South China and the middle and lower reaches of the Yangtze River is more than 15%,among them,the frequency of drought in northern Heilongjiang,southern Shandong,Guangdong,Fujian,Jiangxi,Sichuan,Shaanxi and southern Tibet is more than 25%.Under the RCP 8.5 scenario,the frequency of drought in different areas of China is quite different,and the frequency of drought in most areas of Northwest China is less than 5%,The frequency of drought in Northeast,Huanghuai,southwest,South China and the middle and lower reaches of the Yangtze River is more than 30%,Among them,the frequency of drought in Northeast of Heilongjiang,south of liaolin,south of Shandong,north of Jiangsu,Guizhou,Yunnan,Guangxi,Guangdong,Fujian and is more than 40%.The frequency and degree of drought in RCP 8.5 scenario are higher than those in RCP 4.5 scenario.The drought predictions of different major grain producing areas in China indicate that the drought frequency and degree in the northeast region,the Huanghuaihai region and the middle and lower reaches of the Yangtze River are aggravated under the RCP8.5 scenario.In the Southwest,the drought in the RCP8.5 scenario slowed down compared to the RCP4.5 scenario.