中国农业自然灾害可接受风险水平研究

Acceptable Risk Level of Agricultural Natural Disasters in China

农业自然灾害可接受风险水平的确定是实现农业灾害风险管理和区域农业可持续发展的有效途径。基于2010—2020年中国农业和农业自然灾害(包括干旱、洪涝、地质灾害、台风、风雹、低温冷冻和雪灾等)损失数据(不含港澳台地区数据),分析农业自然灾害的时空分布特征,并在最低合理可行原则(As Low As Reasonably Practicable,即ALARP原则)下,应用F-N曲线法,构建不同风险厌恶程度的全国及其7大地理分区的农业自然灾害可接受风险曲线。结果表明:(1)2010—2020年中国农作物受灾率总体呈下降趋势,农作物成灾率为先波动上升至2015年达最高值后又波动下降,农作物绝收率总体呈上升趋势;华北和西北地区是我国农作物年均受灾率和成灾率最大的地区,而华南地区是农作物年均成灾率和绝收率最小的地区;(2)风险厌恶程度分别为1、1.5和2时,农业自然灾害致1万hm^(2)农作物年绝收的累计频率分别不超过0.12、0.07和0.02为可接受风险,超过0.50、0.15和0.07为不可接受风险。不区分风险厌恶程度,农业自然灾害导致农作物年绝收面积超过300万hm2,其年绝收的累计频率为任意值均是不可接受的。同理,7大地理分区的农业自然灾害可接受风险水平也被依次确定。该研究结果可为中国农业自然灾害风险管理提供决策建议。

Determining the acceptable risk level of agricultural natural disasters is an effective way to realize agricultural disaster risk management and regional agricultural sustainable development.Based on the data of China′s agriculture and agricultural natural disaster losses(including drought,flood,geological disaster,typhoon,wind and hail,low-temperature,freezing and snow disaster)from 2010 to 2020(excluding Hong Kong,Macao and Taiwan data),the temporal and spatial distribution characteristics of agricultural natural disasters are analyzed.Under the principle of As Low As Reasonably Practicable(abbreviation for ALARP),the F-N curve method is applied to construct the acceptable risk curve of agricultural natural disasters in China and its seven geographical regions with different risk aversion degree.The results show that:(1)From 2010 to 2020,the crop affected rate in China generally show a downward trend.The crop damage rate first undulate rise to the highest value in 2015,and then undulate fell.The crop failure rate generally showed an upward trend.North China and Northwest China are the regions with the largest annual crop affected rate and annual crop damage rate in China,while South China is the region with the smallest annual crop damage rate and annual crop failure rate.(2)When the degree of risk aversion is 1,1.5 and 2 respectively,the cumulative frequency of annual crop failure of 10000 hectares caused by agricultural natural disasters is not more than 0.12,0.07 and 0.02 respectively,which is an acceptable risk,and more than 0.50,0.15 and 0.07 is an unacceptable risk.Regardless of the degree of risk aversion,agricultural natural disasters lead to an annual crop failure area of more than 3 million hectares,and the cumulative frequency of annual crop failure of any value is unacceptable.Similarly,the acceptable risk level of agricultural natural disasters in the seven geographical divisions is also determined in turn.The research results can provide decision-making suggestions for agricultural natural disaster risk management in China.