Spatial And Temporal Patterns Of Typical Farming Meteorological Disasters In China In Recent 30 Years And Drought Risk Assessment

Under the background of global climate warming,the meteorological disasters occur frequently and agricultural production is increasingly serious impacted by meteorological disasters,China is a large agricultural country,agricultural production facilities are also relatively weak,we cannot get away from depending on the weather,so that studying changes of agricultural meteorological disasters in China is very important.This paper use most of provinces in China' disaster area causing 10%yield loss,disaster area causing 30%yield loss and sown area,rate of disaster causing 10%yield loss and rate of disaster causing 10%yield loss as the index,using Empirical Orthogonal Function(EOF)analysis to analysis spatial and temporal changes on China's drought,flood,low temperature and hailstorm disasters.The results show that there is a decreasing trend of drought(starting in 2000),hailstorm(beginning in 2001)and low temperature(starting in 2008)except for flood(without obviously change).The EOFs of rate of drought causing 10%yield loss and rate of drought causing 30%yield loss are similar;the situation in the north is obviously higher than that in the South,such as The Loess Plateau.But the EOFs of rate of flood causing 10%yield loss and rate of flood causing 30%yield loss are different,flood area causing 10%yield loss are common in the country,but flood area causing 30%yield loss mainly in the Yangtze River Basin and the Northeast.The EOFs of rate of low temperature causing 10%yield loss and rate of low temperature causing 30%yield loss are basically nonexistent.Roughly,the northern disaster was more severe than the South.There is slight influence form hailstorm in most of China,the West and the North is more serious.Droughts and floods will not continue to affect the northeastern plain all the year round,but will cause serious losses in the event of a disaster.Low temperature disaster will continue to affect most areas of our country without causing serious losses;and the hailstorm will cause sustained and serious losses.Combined with statistical analysis and empirical orthogonal function(EOF)analysis,disaster area causing 10%/30%yield loss of this 4 kinds of disaster do not exactly match.The degree of disaster area causing 10%yield loss and disaster area causing 30%yield loss change is different;the areas affected by disaster area causing 10%yield loss and disaster area causing 30%yield loss focus are different,the sustainable or un sustainable of disaster area causing 10%yield loss and disaster area causing 30%yield loss are not identical.Based on the natural disaster risk theory,a drought risk assessment model was constructed using the PLS-SEM structural equation model.The results show that the structural equation model is feasible in the field of disaster risk assessment and can be used to make hazard factors vulnerable and fragile.The four latent variables of sex and sensitivity,disaster prevention and mitigation capabilities,and disaster risk are quantified.Using the model,taking Liaoning Province as an example,a drought risk assessment was conducted.The hazard,vulnerability,and sensitivity of the hazards,and the ability of disaster prevention and reduction to explain drought risk were as high as 78%.